I had the same PCIe BusError messages in boot and spamming my logs on Asus x550v (Skylake cpu).

Try this:

Current workaround is to add pci=noaer to your kernel command line:

1) edit /etc/default/grub and and add pci=noaer to the line starting with GRUB_CMDLINE_LINUX_DEFAULT. It will look like this:

GRUB_CMDLINE_LINUX_DEFAULT="quiet splash pci=noaer"

2) run sudo update-grub

3) reboot

from Workaround here

note: If pci=noaer doesnt work try use pci-nomsi instead.


cannot boot ubuntu 13.10 with my usb, Can i change the kernal on my laptop to run it?

Your laptop is ok, just try to download the 32 bit version and reinstall. Remember to format the pendrive before.


monitor or watch a process and restart if it goes down

I'd suggest Monit. You can install it from Synaptic or sudo apt-get install monit. I use it on my server to monitor my SSH, Apache, etc and restart them if they fail.


Warning: If you follow these instructions you must install testdisk on a different Ubuntu system than the one you're trying to recover (for example, you could install it in a live environment, or you could put the hard disk into another computer that has Ubuntu on it). If you install anything on a disk from which you wish to recover data, or save anything to it, it becomes far harder to recover anything because more data are overwritten.

You can try testdisk to recover it. I hope you can recover it, because you didn't formatted the space it. Only the partition table is changed.

Install it via Software center testdisk

or by using sudo apt-get install testdisk command in the terminal.

Then run it with sudo command, i.e sudo testdisk. Please Don't forget to read the manual of it. manpage for the testdisk command


Answer here:  Fixed it with this:  http://ubuntuforums.org/showthread.php?t=2300362


What purpose does this ppa file in sources.d serve and why did they create errors on apt-get update?

Yes, those lines are causing the errors. They do not make any sense all and may be the result of a copy&paste error or something similar.

Just remove the whole file.


Unity problems after installing GNOME desktop (ubuntu-gnome-desktop)

Fixes for my ubuntu-gnome-desktop post-installation problems...

Desktop problems: Use the Gnome Tweak Tool, and set "Icons on Desktop" to ON
Font problem: Use the Unity Tweak Tool, and set the fonts back to Ubuntu default fonts
Touchpad problems: Fix taken from How to invert touchpad scrolling on Ubuntu 16.04

If you use libinput, then add a config file to /etc/X11/xorg.conf.d/ such as 20-touchpad.conf with this content:

Section "InputClass"
    Identifier "libinput touchpad catchall"
        MatchIsTouchpad "on"
        MatchDevicePath "/dev/input/event*"
        Driver "libinput"
        Option "NaturalScrolling" "off"
        Option "MiddleEmulation" "on"
        Option "Tapping" "on"
        Option "DisableWhileTyping" "on"
        Option "PalmDetection" "True"
EndSection

Login screen problem: User desktop must be set to display a desktop picture, not a solid color
Default DE problem:

In terminal...

gksudo gedit /etc/lightdm/lightdm.conf

add in this text snippet under [SeatDefaults]...

[SeatDefaults]
user-session=ubuntu

don't duplicate [SeatDefaults] if it's already there.

Boot/shutdown screens problem: Partially taken from How do I revert the Plymouth theme back to default after purging Kubuntu?

In terminal...

ls -al /etc/alternatives/*plymouth*
sudo update-alternatives --config default.plymouth
sudo update-alternatives --config text.plymouth


How to change default program for http(s):// links in Xubuntu/XFCE

Change default browser using update-alternatives --config x-www-browser:

$ update-alternatives --config x-www-browser

There are 2 choices for the alternative link group x-www-browser \
(providing /usr/bin/x-www-browser).

  Selection    Path                Priority        Status
------------------------------------------------------------
* 0            /usr/bin/firefox         50        auto mode
  1            /usr/bin/chromium        10       manual mode

Press <enter> to keep the current choice[*], or type selection number:

The current choice has a *. Just press the number of the browser you want to use. In this example I would type 1 to make Chromium the default browser.


Django Project Runs With runserver, But Not With Gunicorn and nginx

This is what the documentation says:

Virtual Environment and Python Version
When using a Python virtual environment with mod_wsgi, it is very important that it has been created using the same Python installation
that mod_wsgi was originally compiled for. It is not possible to use a
Python virtual environment to force mod_wsgi to use a different Python
version, or even a different Python installation.
You cannot for example force mod_wsgi to use a Python virtual environment created using Python 3.5 when mod_wsgi was originally
compiled for Python 2.7. This is because the Python library for the
Python installation it was originally compiled against is linked
directly into the mod_wsgi module. In other words, Python is embedded
within mod_wsgi. When mod_wsgi is used it does not run the command
line python program to run the interpreter and thus why you can’t
force it to use a different Python installation.


Grep -E, Sed -E - low performance when '[x]{1,9999}' is used, but why?

Note that it's not the matching that takes time, but the building of the RE. You'll find that it uses quite a lot of RAM as well:

$ valgrind grep -Eo '[0-9]{1,9999}' < /dev/null
==6518== HEAP SUMMARY:
==6518==     in use at exit: 1,603,530,656 bytes in 60,013 blocks
==6518==   total heap usage: 123,613 allocs, 63,600 frees, 1,612,381,621 bytes allocated
$ valgrind grep -Eo '[0-9]{1,99}' < /dev/null
==6578==     in use at exit: 242,028 bytes in 613 blocks
==6578==   total heap usage: 1,459 allocs, 846 frees, 362,387 bytes allocated
$ valgrind grep -Eo '[0-9]{1,999}' < /dev/null
==6594== HEAP SUMMARY:
==6594==     in use at exit: 16,429,496 bytes in 6,013 blocks
==6594==   total heap usage: 12,586 allocs, 6,573 frees, 17,378,572 bytes allocated

The number of allocs seems roughly proportional to the number of iterations, but the memory allocated seems to grow exponentially.

That's down to how GNU regexps are implemented. If you compile GNU grep with CPPFLAGS=-DDEBUG ./configure && make, and run those commands, you'll see the exponential effect in action. Going deeper than that would mean going through a lot of theory on DFA and dive into the gnulib regexp implementation.

Here, you can use PCREs instead that doesn't seem to have the same problem: grep -Po '[0-9]{1,65535}' (the maximum, though you can always do things like [0-9](?:[0-9]{0,10000}){100} for 1 to 1,000,001 repetitions) doesn't take more time nor memory than grep -Po '[0-9]{1,2}'.


Keyboard shortcut for terminal in Ubuntu 16.10 not working

As stated by David Foerster Nautilus doesn't support the accel map anymore (currently I'm testing on Ubuntu 17.10).

I found the answer on https://askubuntu.com/a/696901/44054

Just a note, the script on ~/.local/share/nautilus/scripts must have no extension. If you put an extension it won't work (at least in my case it didn't). Also, remember to make it executable.

Solution

(In case the link and the solution is broken)

So in my case it was a

echo "#! /bin/sh
gnome-terminal" > ~/.local/share/nautilus/scripts/Terminal

chmod +x ~/.local/share/nautilus/scripts/Terminal

Then, I just created

echo "F12 Terminal" > ~/.config/nautilus/scripts-accels

Then, after restarting nautilus, the terminal is opened through that script by pressing F12.


If you don't intend to keep Deepin Linux, an easier and standard way of doing this is to create a live USB disk. As long your computer is not old (not more than a few years old), your computer should be able to boot from the USB disk. To create a live USB disk, download UNetbootin, run it and select Ubuntu as the distribution and the version, or if you have the disk image downloaded enter the path in the text field at the bottom. Then go through the wizard and let it do its job.


Runaway "Bouncy Ball" widget that can't be caught or killed

GOT IT !!!

vi /home/username/.kde/share/config/plasma-desktop-appletsrc

then edit the line

AutoBounceEnabled=true
Gravity=4

to something like this

AutoBounceEnabled=false
Gravity=88

then logged out and back in. Then I was able to grab a hold of it and remove it.

OMG that was so hilar. What a screwup that was.


Try install the broadcom driver and wireless tools packages:

sudo apt-get install broadcom-sta-common wireless-tools


I did not install postgresql, so why do I have postgresql related binaries in 12.04?

Probably some other installed package depends upon postgresql, so the binaries got pulled in.  You can run

apt-cache rdepends postgresql

to see all the reverse dependencies.


Cannot connect client to landscape server: certificate issue

I will answer with the solution that worked for me, but it might be very specific. My problem was a machine-name problem. When I ran either "hostname" or "hostname -f" on the server, I got the response

servername

but I couldn't ping that server - ping servername fails. I had to ping servername.local to get a response (notice that local is NOT a placeholder. If my server was named "servername", the actually thing I'm typing is ping servername.local).

Anyway, the answer is to change servername to servername.local in all the landscape configuration files, as well as the SSL you created via those instructions. This includes the apache2 configuration files, and anywhere else in the landscape configuration files you specified the name of the server. Also, connect to servername.local from the Landscape clients.

(Again, it's possible this is a quirk of my local network, since I am not the manager and don't quite know how names are resolved on it. In any case, I was getting very similar error messages)


Taken from Nathan Campbell's answer to this question:  Wine can't find gnome-keyring-pkcs11.so

Getlibs can be found here: https://launchpad.net/~jcollins/+archive/jaminppa/+build/1482994/+files/getlibs_2.06-0ubuntu1%7Eppa2_all.deb


Speakers not working properly on HP Elitebook 8440p

Finally I fixed it.

I followed the instruction of the last post of this thread:
link (linked by this other one: link ),

and I set the last line of alsa-base.conf as follows:

options snd-intel-hda model=auto,auto enable_msi=1,0 index=0,1 id=Intel,NVidia

After shutdown (simply rebooting does not work, I don't know why) everything seems to work fine..


matplotlib error : MatplotlibDeprecationWarning

You have a MatplotlibDeprecationWarning when using the version of Matplotlib that was installed by pip. Install Matplotlib from the default Ubuntu repositories instead. Open the terminal and type:
sudo apt install python2.7 python-matplotlib # 18.04 and earlier
sudo rm -r /usr/lib/python2.7/site-packages/matplotlib/

Run the following commands in python:
matplotlib.get_configdir()
matplotlib.get_cachedir()

Remove the matplotlib packages in the output paths of these commands. If there aren't any matplotlib packages in the output paths of these commands continue on to the next step.
Remove the matplotlib files in the .local folder.
mv /home/rishabh/.local/lib/python2.7/matplotlib* /home/rishabh/tmp

Type python to start the Python interpreter and then after the prompt type:
from matplotlib import pyplot as plt

You might also like to try running the plots inline in Spyder Python IDE.
sudo apt install python2.7 ipython python-matplotlib spyder # in Ubuntu 18.04 and earlier

After the ipython prompt in the IPython console copy/paste the below code and press the Enter key to run it.
import matplotlib.pyplot as plt
x, y = [-1, 12], [1, 4]
plt.plot(x, y, marker = 'o')


How to disable the discrete gpu? I get 'Kernel failure' with the normal method

The correct command isn't OFF but IGD. If you  Exerpt from the wiki:

  Once you've ensured that vga_switcheroo is available, you can use
  these options to switch between GPUs. Be prepared for a lockup (either
  immediately, or after a minute), the existence of this file does not
  mean that the machine is supported.

echo ON > /sys/kernel/debug/vgaswitcheroo/switch

  ^ Turns on the GPU that is disconnected (not currently driving outputs),
  but does not switch outputs.

echo IGD > /sys/kernel/debug/vgaswitcheroo/switch

  ^ Connects integrated graphics with outputs.

echo DIS > /sys/kernel/debug/vgaswitcheroo/switch

  ^ Connects discrete graphics with outputs.

echo OFF > /sys/kernel/debug/vgaswitcheroo/switch

  ^ Turns off the graphics card that is currently disconnected.

You should run then sudo sh -c "echo DIS > /sys/kernel/debug/vgaswitcheroo/switch" to switch to the discrete graphics card. For switching back to full power use sudo sh -c "echo IGD > /sys/kernel/debug/vgaswitcheroo/switch".

To look into kernel failures message, you should check the /var/log/kern.log.0 and /var/log/dmesg.0.


Values cannot be changed in CompizConfig System Manager (CCSM) when using

Found a workaround but still don't understand why the super key is locked from usage.

Steps for the workaround:

1. Change the key in CCSM to something without super (Should work).

2. Find the new key in dconf dump. dconf dump / | less + search for the new key combination. Found something of the following:

[org/compiz/profiles/unity/plugins/grid]

put-maximize-key='<Control><Alt>Up'

put-restore-key='<Control><Alt>Down'

left-maximize='<Alt>Left'

3. Write the new value. Example:

dconf write /org/compiz/profiles/unity/plugins/grid/left-maximize "'<Super><Control>Left'" (see the left-maximize in the command)

4. Check that it was written correctly:

$ dconf read /org/compiz/profiles/unity/plugins/grid/left-maximize

'<Super><Control>Left'


To change the name on Ubuntu (unlike OS X) you need to right-click and then choose 'rename'.  If you then cannot type to change the name, that's a bug.  As a workaround you could try then left-clicking on the name to see if that puts focus in the right place.

It could be that you're hitting the problem described in gnome bug 646900, which is fixed upstream and should be fixed in Ubuntu in a bit.  That bug reports suggests some workarounds.

If that doesn't sound like your bug, I suggest you report it by running in the Terminal:

apport-bug nautilus


How to login with non-root user on crouton Chromebook

startxfce4 starts XFCE as the user you run it as - root in this case.

To use GUI login, you have to install a display manager. For Xfce4 I believe it's LightDM.


not command 'subl' found, trying to open ~/.bash_profile with it

subl is a command in OSX, not Linux.

I would suggest using the simple text editor nano for editing files. The correct command would be:

nano ~/.bash_profile

If you really need to use sublime-text there's a guide to installing it here. If it's already installed you'd have to make alias files, or symlinks, to use subl, which is described near the bottom of the linked article.


Ubuntu 18.04 on WSL cron daemon not running after reboot

As it is described in the article Starting Linux Background Services on Windows Login you need to trigger your command sudo service cron start from Windows. You can use Windows Task Scheduler for this purpose. Here are the steps from the mentioned article with a slight modifications:

1. Create startup script and make it executable:

echo "service cron start" | sudo tee /usr/local/bin/cronstart.sh
sudo chmod +x /usr/local/bin/cronstart.sh

Thus cronstart.sh will be accessible as shell command system wide.

2. Create a file within /etc/sudoers.d/ with purpose to allow your $USER to execute cronstart.sh by sudo without password. Run the following command to generate the line that must be placed in the sudoers file:

echo "$USER ALL=(ALL) NOPASSWD: /usr/local/bin/cronstart.sh"

Copy the output of the command, use the command sudo visudo -f /etc/sudoers.d/cronstart and paste the copied line as content of the newly created file. Save the file and exit.

3. Within Windows, go to the search bar, find and run Task Scheduler (as administrator if your current account isn't administrators one).

Now, click Task Scheduler Library on the left and then Create Task… on the right to create a new task. You can use the following parameters to configure the task:

General tab:

Name the task anything you want, like WSL service cron start.

Choice the option Run whether user is logged or not.

Mark Do not store password and Run with highest privileges.

In the Configure for dropdown select Windows 10.

If you need to setup a task for another user click on the button Change User or Group....
Triggers tab:

Click New… to add a new trigger for this task.

In the Begin the task dropdown select At startup.

Within the Advanced settings you can check Delay task for 1 minute.
Actions tab:

Click New… to add a new action for this task.

Pick Start a program for the action type and then enter C:\Windows\System32\wsl.exe as the program to run.

At Add arguments (optional) set this: sudo cronstart.sh.

That’s it. Reboot the system, then open WLS terminal and use service cron status to check whether cron is running.

I've made some tests and unfortunately I found Windows 10 experiences some bugs and it is almost impossible to setup such task for a non-administrator user's account, while you are using Windows account instead of local one ... complete mess :O

As workaround in this case you can create a file called cronstart.bat in the folder shell:startup with content as follow:

C:\Windows\System32\wsl.exe sudo cronstart.sh

How to use VBS instead of a bat file to achieve the same result is shown here:

Windows Subsystem for Linux Autoload Apache2 and MySql


Upgrade from Linux Mint 12 to Kubuntu 12.04?

You can't.

Mint and Ubuntu, no matter how closely related they are (or aren't, as the case might be) are still two different operating systems.

This is a bad idea.

First, you're mixing two different distributions' packages together. For various reasons, this is a bad idea:

Security.
Stability.
Conflicting updates.
If you let updates go through, you encounter the first two problems, and then you're in deep trouble if say, as an example a kernel update comes through!

Also, this makes getting an accurate bug report or stacktrace almost impossible, if not entirely impossible.


Is there a list of suggested hardware specs for trying Ubuntu Openstack?

CPU and storage requirements are not mentioned because it varies greatly. Generally speaking, your cloud will deploy just fine on server-class hardware that meets the two disks and two NICs requirement.

The resources - number of instances you can start, storage space available, etc, will depend on the specs of the hardware you use to build your cloud. You should have hardware appropriate to your intended usage.


How to create package including source codes, which compile during installation

That's not how .deb packages work. They contain pre-compiled software, you can't just make a deb package with source code. I have a suggestion: why don't you make a .tar.gz package containing your source code and a script to compile it? The script should look like this:

#!/bin/bash

# here comes the code to compile your source code, like the usual. Change to fit your needs.

./configure

make

make install


how to generate missing pages in libreoffice writer

From a thread in the OpenOffice.org forums: you need to enable the option "Print automatically inserted blank pages" in Writer's Print options (Menu "Tools" -> "Options" -> "LibreOffice Writer" -> "Print"). It's not active by default.

Notice that this will affect only printing. When exporting the file to PDF, the option to automatically insert blank pages will be ignored. As a workaround, you could use a "PDF Printer" to create a PDF.


Ubuntu 16.10 Acer Swift-3 multiple problems

The answer is simple, but first a little bit of backstory. I too, own one of these machines, and I was famished when I found that Ubuntu would hang and would boot 1/10 percent of the time.

The reason is the following. The Acer Swift 3 firmware and the ACPI firmware in Linux 4.11 & below have a bit of a conflict...

But the solution is this! Linux kernel Devs fixed it in Kernel 4.12 and above! Ubuntu 17.10 officially comes with the latest kernel, but it will release after a few months. so a TEMPORARY solution (not recommended by me, see below why) is to boot an Ubuntu ISO with the Mainline / unstable 4.12 or above kernel, or boot Ubuntu with acpi=off, use a separate mouse and keyboard, install the Mainline Kernels, and remove that acpi=off from the grub boot commands.

Why is this not a good solution? because Mainline kernels have many bugs and stuff, and I got harsh karma from using Mainline kernels. my new Acer Swift 3's battery total went from 100% to 98%!!! I can never charge my laptop to its full potential now! And that is to be expected in any laptop, but the reason why this is such a big problem is because the battery went down in 1 day!! within a day, the total of my new laptop took a hit. that is why I will use Linux on MY Acer Swift 3 only once Ubuntu 18.04 releases (for stability, but 17.10 will also work) But you are free to go ahead and use risky software and kernels.

LINK for Ubuntu ISO with mainline kernel -> http://linuxiumcomau.blogspot.com/2017/06/interim-ubuntu-1704-iso-with-mainline_29.html
TIP - Install That ISO, and upgrade its Mainline kernel to the latest, or at least to 4.12, because it comes with 4.12RC7. Or maybe try an "unstable" Ubuntu kernel, but be warned, battery life takes a hit when using these kernels, so remember to use TLP ;) Good Luck!


How do I rename a mounted Truecrypt volume?

The prior solutions did not work if you have ext3/4 volumes.  This is a solution for that case:

Find the ID using >> sudo fdisk -l

  Disk /dev/mapper/truecrypt2: 128.8 GB, 128000000000 bytes
  255 heads, 60 sectors/track, 15000 cylinders, total 250000000 sectors
  Units = sectors of 1 * 512 = 512 bytes
  Sector size (logical/physical): 512 bytes / 512 bytes
  I/O size (minimum/optimal): 512 bytes / 512 bytes
  Disk identifier: 0x1234567

Find the ID (bolded above) for the volume of interest.  Your location WILL be different!

Use e2label: >> sudo e2label /dev/mapper/truecrypt2 newname

Again, make sure you use YOUR drive information.


Why does Firefox (update in background) fail while in use? Is it a Firefox or Ubuntu 20.04 thing?

I have had Firefox automatically update for me all the time in the past.  But, this can be disabled.  The version of Firefox that is in the Ubuntu repositories no longer has the checkbox under the General tab of Preferences to enable or disable the automatic updates.
However, if you go to your address bar and type in about:config and bring it up you can set the automatic updates to disabled so that you only update Firefox then with the apt upgrade command.
Open Firefox and go to about:config

Accept the risk and continue

Type in update into the search box then double click app.update.auto to false for disable the automatic updates.


Intel 8265 Bluetooth finds unavailable devices

Have the same notebook with same config and had the same problem with Debian Stretch.

The location is /var/lib/bluetooth/

There is a folder XX:YY:Z1.... (MAC of your build-in bluetooth device).

In this folder (XX:YY:Z1....) are other folders with the naming shema XX:YY:Z2.... (already configured bluetooth devices) and also a folder named cache, which contains files with the naming shema XX:YY:Z3....  (already found bluetooth devices).

You should look in the cache folder and delete all files there. Then they will not appear as already found.

If you want to delete a already configured device delete the XX:YY:Z2.... folders in the "main" folder of your build-in bluetooth device.

to be able to invoke

sudo -i

to get root access and delete files with

rm file_name

or folders with

rm folder_name -rf

Hope this helps.

I also have the

[bluetooth]# Failed to pair: org.bluez.Error.AuthenticationCanceled

Error while trying to pair a Microsoft 3600 mouse.

If someone finds a way to solve it or knows what this error message means please let us now :)


How can I slove postgresql-9.3-postgis-2.1 unmet dependencies Ubuntu 14.04

After some additional research I found the answer via the following questions
How do I resolve unmet dependencies after adding a PPA? which can be applied to this question as a solution.

In your terminal run

software-properties-gtk

Under Ubuntu Software tab, enable all the repositories

Next run

sudo apt-get update
sudo apt-get upgrade

Finally run

sudo apt-get install  postgresql-9.3-postgis-2.1

Worked successfully for me I hope this helps someone with the same issue install postgresql-9.3-postgis-2.1 with unmet dependencies on Ubuntu 14.04


Apt supports a few protocols, listed in man sources.list. The default is usually HTTP, but FTP and HTTPS repositories are also available. Check your /etc/apt/sources.list to be sure. Since you can specify ports in the URIs, (like deb http://foo.bar:9090/xyz ...), non-standard ports can also be used.

URI SPECIFICATION
   The currently recognized URI types are:

   http (apt-transport-http(1))
       The http scheme specifies an HTTP server for an archive and is the
       most commonly used method. The URI can directly include login
       information if the archive requires it, but the use of
       apt_auth.conf(5) should be preferred. The method also supports
       SOCKS5 and HTTP(S) proxies either configured via apt-specific
       configuration or specified by the environment variable http_proxy
       in the format (assuming an HTTP proxy requiring authentication)
       http://user:pass@server:port/. The authentication details for
       proxies can also be supplied via apt_auth.conf(5).

       Note that these forms of authentication are insecure as the whole
       communication with the remote server (or proxy) is not encrypted so
       a sufficiently capable attacker can observe and record login as
       well as all other interactions. The attacker can not modify the
       communication through as APTs data security model is independent of
       the chosen transport method. See apt-secure(8) for details.

   https (apt-transport-https(1))
       The https scheme specifies an HTTPS server for an archive and is
       very similar in use and available options to the http scheme. The
       main difference is that the communication between apt and server
       (or proxy) is encrypted. Note that the encryption does not prevent
       an attacker from knowing which server (or proxy) apt is
       communicating with and deeper analyses can potentially still reveal
       which data was downloaded. If this is a concern the Tor-based
       schemes mentioned further below might be a suitable alternative.

   file
       The file scheme allows an arbitrary directory in the file system to
       be considered an archive. This is useful for NFS mounts and local
       mirrors or archives.

   cdrom
       The cdrom scheme allows APT to use a local CD-ROM, DVD or USB drive
       with media swapping. Use the apt-cdrom(8) program to create cdrom
       entries in the source list.

   ftp
       The ftp scheme specifies an FTP server for an archive. Use of FTP
       is on the decline in favour of http and https and many archives
       either never offered or are retiring FTP access. If you still need
       this method many configuration options for it are available in the
       Acquire::ftp scope and detailed in apt.conf(5).

       Please note that an FTP proxy can be specified by using the
       ftp_proxy environment variable. It is possible to specify an HTTP
       proxy (HTTP proxy servers often understand FTP URLs) using this
       environment variable and only this environment variable. Proxies
       using HTTP specified in the configuration file will be ignored.

   copy
       The copy scheme is identical to the file scheme except that
       packages are copied into the cache directory instead of used
       directly at their location. This is useful for people using
       removable media to copy files around with APT.

   rsh, ssh
       The rsh/ssh method invokes RSH/SSH to connect to a remote host and
       access the files as a given user. Prior configuration of rhosts or
       RSA keys is recommended. The standard find and dd commands are used
       to perform the file transfers from the remote host.

   adding more recognizable URI types
       APT can be extended with more methods shipped in other optional
       packages, which should follow the naming scheme
       apt-transport-method. For instance, the APT team also maintains the
       package apt-transport-tor, which provides access methods for HTTP
       and HTTPS URIs routed via the Tor network.


How to configure GRUB loader during apt-get upgrade on Ubuntu 12.04

From OP's comment, we came to know that, he solved the problem by installing GRUB on both /dev/sda and /dev/sdb. The comment reads as

  FYI, I got it to work, installed GRUB on both /dev/sda and /dev/sdb.


Anything similar to Maya for making animation-movies under Ubuntu?

Yes there is a very powerful 3D modelling and animation package called Blender.  You can get the latest version from the link.

Blender is an integrated 3d suite for modelling, animation, rendering,
post-production, interactive creation and playback (games). Blender has its
own particular user interface, which is implemented entirely in OpenGL and
designed with speed in mind. Python bindings are available for scripting;
import/export features for popular file formats like 3D Studio and Wavefront
Obj are implemented as scripts by the community. Stills, animations, models
for games or other third party engines and interactive content in the form of
a standalone binary are common products of Blender use.

Alternatively you can find a earlier version in the software centre.


Hard disk makes weird noises during installation

If you think you may have hardware issues with your HDD, you should check it's SMART status. Boot your computer with an Ubuntu LiveCD and check your drive status through Disk Utility (System -> Administration menu).
See this answer for a more detailed explanation.


That is supposed to be done by Ubuntu Maintainers in their repository unless you build it from sources (a bad practice to new bees which I presume you did not do). So just install the package needed, that is:

sudo apt-get install  build-essential


Differences between Qt and GTK programs?

GTK and Qt are user interface toolkits and frameworks. GTK is the standard toolkit for GNOME/Ubuntu while Qt is used in KDE/Kubuntu. From the user's point of view I'd say it's just the looks that differ.


How to delete this files with wildcards in ubuntu terminal

You don't need the " ' " around your wildcard. Just use rm -rf *.upload. And if they are just files you don't need the -r option.

EDIT:

Actually, because you have a "-" at the beginning of your file's name, the command line tries to interpret it as an option for the command, messing things ups. What you need to do is to select the file using ./ like so: rm ./*.upload. I can't explain more why it does that, but this should work.


Where is the system-wide $PATH variable set?

The (default) system wide PATH is set in the /etc/environment file.

$ cat /etc/environment
PATH="/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games:/usr/local/games"

It is basically the place to save the global environment variables.


Format Windows partition (to delete all) and expand my Ubuntu partition

Could work but the partitions are in the wrong order for it to have good result. Once the windows partition is gone and divided up then grub will fail on your existing install as the location on the drive will change for the partition number. Really your best option is to backup your home on the Ubuntu install and re-install with a corrected partitioning as you want it to be. Leaving space at the start of the drive for a new Windows install. If installing Windows again it will mess up the boot loader of Grub, then this will need a re-install. So the Windows should be installed onto that first partition on the drive you are allowing for too first before the Ubuntu, then everything is in place as you want it to be with both OSs installed in working configuration.


Why Chromium version 37 is shutting down when I search something on Google?

I disabled all extensions and the browser started to work again. It seems the extension that generated the crashes was Buffer 2.6.4. Problem solved, thx to @Rinzwind's advice.


On which partition is my bootloader installed?

sudo fdisk -l /dev/sda

Where sda is the disk you want to check the partitions, one of them should be listed as boot partition, if you have more then 1 disk there can be other partitions marked as boot, the next logical disk is sdb followed by sdc, etc.

If you have more then a disk and more than 1 partition is marked as boot the booting will be determined by the selected boot device in your BIOS.


So, after lots of research from multiple websites and hours of reading (and no help from this post):
Here is what I used to increase my battery life from 45min to 2:15 fully charged.
Installed the following programs
Powertop
Laptop Mode Tools
Jupiter

I then figured out how to enable Intel i915 RC6 by using the following commands:

gksudo nautilus

which enabled me to have root access to the /etc/default/grub file
that I then modified the following lines

GRUB_CMDLINE_LINUX_DEFAULT="quiet splash"

to:

GRUB_CMDLINE_LINUX_DEFAULT="quiet splash i915.i915_enable_rc6=1"

and then used the terminal command:

sudo update-grub

Next I uninstalled all programs I was not using or would not use (including all the default media applications which I replaced with VLC) especially anything related to "bluetooth" as I have no bluetooth devices.

I also made sure that beagle and updatedb are disabled such that they won't consume unnecessary power.

I managed to do all of this after literally hours of reading about how to properly use the terminal, multitudes of google searches, and a composition notebook now half filled with terminal commands and lists of apps.

Ultimately I feel as though powertop, laptop mode tools, and jupiter are all basically doing the same thing from different angles and should all just be things that Ubuntu already should have, but that would just be crazy wouldn't it?


How can I update vim to a newer version than 11.04's repo version (7.3.35)

Similarly, can't find a more up-to-date PPA on Launchpad.  The 11.10 repositories have yet to be updated with a more recent version than in Natty.

You could uninstall VIM and compile the most recent source as per this AU answer: Where can I find Vim 7.3?

Alternatively you could try the Debian unstable packages here: http://packages.debian.org/sid/vim


how to find a word in text files from a directory

If you don't want to  install additional software, you can simply use grep in the terminal. To recursively search through directories, you can use the -r option (see man grep for details). The syntax you are looking for is probably:

grep -r "[STRING TO SEARCH FOR]" "[DIRECTORY TO SEARCH]"

So, for instance if I want to search for the string "asdf" in all files in all subdirectories of "/tmp/testdir/" the command looks like this:

grep -r "asdf" "/tmp/testdir/"

The quotation marks are not strictly necessary, but if your string or directory path contains whitespaces, you otherwise would have to mask them using the \ character...


How can I find out which package is triggering the installation of i386 libraries when using Ubuntu 64bit?

What I would try to identify which package triggered installation of 32 bit packages:

start synaptic
find a 32-bit package which has been installed as a dependency (libc6-i386 is a good candidate)
try to uninstall it. If another package depends on it (which should be the case because that's why the library has been installed in the first place), Synaptic will tell you that you need to uninstall that another package as well.
once you uninstalled the package which triggered installation of the 32-bit libs, you can run sudo apt-get autoremove to remove packages which were installed as dependencies of uninstalled packages.

Similarly, to find all packages which depend on 32-bit libs, try to uninstall, say, libc6-i386 - this should trigger un-installation of all 32-bit packages in the system.

I'm sure there's also a magic command line one-liner involving dpkg, awk and grep which does the same :)


mono 3.2.8 (or 3.4) installation on ubuntu 12.04 help needed

This should install the latest version:

sudo apt-key adv --keyserver hkp://keyserver.ubuntu.com:80 --recv-keys 3FA7E0328081BFF6A14DA29AA6A19B38D3D831EF
echo "deb http://download.mono-project.com/repo/debian wheezy main" | sudo tee /etc/apt/sources.list.d/mono-xamarin.list
sudo apt-get update
sudo apt-get install mono-complete


Your mount command is not the good one. You must call the disk drive device, not the root symbol ie

sudo mount /dev/sdZX /mnt/root
sudo mv /mnt/root/var /mnt/root/var.old
sudo umount /mnt/root


How do I get 'Run' on the Lubuntu Start menu to respond to the R key?

You do realize that you can start a program from the terminal.  Anyway, according to the Lubuntu documentation https://help.ubuntu.com/community/Lubuntu/Keyboard#Create_New_Keyboard_shortcuts

  There is no automatic way to create new keyboard shortcuts or hotkeys
  in lubuntu. You will either have to edit Lubuntu's openbox
  configuration file (~/.config/openbox/lubuntu-rc.xml) and edit, or
  alternatively install xbindkeys.

  Obkey will edit the keyboard parts of your Openbox configuration file
  for you. Download the .tar.gz and unarchive it. After unpacking the
  tar.gz, open a command line in the new folder and run obkey like this:
  ./obkey ~/.config/openbox/lubuntu-rc.xml Hint: back up your config
  file. After saving the config file, you will need to run this command
  to have openbox use the changed config: openbox --reconfigure

  For more information on the syntax of the configuration file, please
  check out the official Openbox documentation on bindings. Note that
  Super_R and Super_L are the two "Windows" keys when you just want to
  use those keys. If you want to couple them with something else, use W-
  plus whatever key you want to use.


PlayOnLinux is a front-end for Wine.  Wine actually uses CUPS to print.  You might need to configure CUPS for your printer of choice so you can print from your Wine applications.

First, make sure CUPS is installed:

sudo apt install cups

After CUPS is installed, you can access the CUPS admin page from a web browser by accessing the following address:

http://127.0.0.1:631

Check the printers tab to see if any printer has been added:

If you have a printer, then you should be good to print.  If not, add one by clicking on the Administration tab.  Then click on the Add Printer button:

Next, it should come up and show you all printers on your system.  Click the printer you want to use:

Click continue.  It should be now showing you the information about your printer.

If it all looks good, click continue again.  Now you get more information.

If that looks good, now click Add Printer button.  It should bring you to the default settings.

Click Set Default Options.  Now your printer should be added.

You will need to close all Wine apps first.  Now, in your Office 2007 apps, when you print you should now see the printer to print to.

Hope this helps!


How do I get a display resolution above 1024x768 on my ATI Radeon x800

Exactly which model of X800 do you own?  This Link states that for the "Pro" variant the maximum resolution is "1600x1200" which falls short of the HDTV's expected 1080p resolution of 1920x1080.  Different models have different maximum resolutions so specifying the exact model you own and also whether it is AGP, PCI, or PCIe will help as well.


The .virtualenvs directory is usually in your home directory.
The output suggests that the python executable cannot be found.

Try running ~/.virtualenvs/sk/bin/python3 main.py


How to access files in Windows partition from Ubuntu live USB?

You need to mount the partition that contains you files.
Run this on Terminal:

sudo fdisk -l

It should be something like

   Device Boot      Start         End      Blocks   Id  System
/dev/sda1   *        2048      206847      102400    7  HPFS/NTFS/exFAT
/dev/sda2          206848   209717247   104755200    7  HPFS/NTFS/exFAT

To locate which partition has your files, probably the one Windows 7 is installed in, then perform the following command:

sudo mount -t ntfs-3g /dev/sdaX /~/choose-a-folder-name-you-want

Where X is the number of the partition you want to mount, like /dev/sda1 or /dev/sda2.

It should mount the disk with full access, so you can copy and paste files to those folders. More about mount.

Remember, it will mount your whole Windows 7 partition to a folder, so be carefull not to delete anything important.


I have never used this thing, simply downloaded binary from official site.

At first install Koala (as normal user):

sudo apt install git npm ruby ruby-dev libgconf-2-4

cd ~/Downloads
wget https://github.com/oklai/koala/releases/download/v2.3.0/koala_2.3.0_x86_64.tar.gz
tar -xf koala_2.3.0_x86_64.tar.gz
usr/share/koala/Koala

It launches normally:

but I do not how to test it further.


I use an old Samsung laser printer myself and it works fine. When I first got it, there was not a specific driver for it available. In cases like this you can generally use the "next nearest" model's driver with little or no loss in functionality.

If the printer understands PostScript, you can use the printer with a generic PostScript driver if you only print structured documents instead of bitmap images or the like.

Depending on what country you are in, local consumer law may also allow you to buy the printer and then return it if it is "not fit for purpose", but this is of course inconvenient and not really fair on the vendor either.

Also have a gander at openprinting.org and see if there's any info on your model.


From your wireless-info output:

wlp3s0    Link encap:Ethernet  HWaddr <MAC 'wlp3s0' [IF2]>
          inet addr:172.21.227.43  Bcast:172.21.255.255  Mask:255.255.0.0
          inet6 addr: fe80::a06b:d623:7a53:48a/64 Scope:Link
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:95202 errors:0 dropped:0 overruns:0 frame:0
          TX packets:81103 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000
          RX bytes:124882281 (124.8 MB)  TX bytes:8863246 (8.8 MB)

On the 4th line, MTU:1500 shows the misconfiguration. MTU is the Maximum Transmission Unit, the size, in bytes, of the largest packet your system will send. Any larger lump-of-data to send will be split into multiple packets.

An MTU:1500 setting will cause your system to send 1500 byte packets to wlp3s0, which, because it's wireless, will wrap your 1500-byte packet in some additional metadata, making the actual packet length larger than 1500. Your ONE packet will have to be split into TWO packets to transmit. It takes longer to send two packets.

What can be done?

Install the iputils-tracepath package:

sudo apt-get install iputils-tracepath

Read man tracepath, then

tracepath -n slashdot.org

and look at the pmtu (Path MTU) value. Remember this number! Or, have the shell remember it for you:

 newMTU=$(tracepath -n slashdot.org| grep -o 'pmtu [0-9]\+'| tail -n 1 | awk '{print $2}')

Then, change the MTU. Since the MTU configuration setting is used in setting up the connection, you must do the Down-Change-Up dance. Note this is going to break all connections going through wlp3s0, so, if you're administering this system remotely (via ssh) you will be disconnected.

sudo ifconfig wlp3s0 down
sudo ifconfig wlp3s0 mtu $newMTU
sudo ifconfig wlp3s0 up

Alternate method:

Change the configuration of your router to provide the $newMTU value via DHCP, then take wlp3s0 down and up.


All SMS are stored in $HOME/.local/share/history-service/history.sqlite.

So you can try (if you know well sqlite) to import all of it manually via SQLite (but, before do anything, backup the sqlite file, you might lose all of your sms is you do an mistake).

So an ability in SQL and XML is required to follow this "method".


18.10 Getting "Package sgml-base is not configured yet." when running apt-get -f install as root

Try to remove remove problematic file with

sudo rm -rf /var/lib/sgml-base/supercatalog

and then reinstall three packages:

sudo apt-get install sgml-data metacity-common sgml-base --reinstall


How to reset the channels and get back to the stable release

This is not possible. There isn't a "safe" way to downgrade packages between releases. The only way is a total reinstall of the system.


How to stop a bash while loop running in the background?

I started

while true; do yad; sleep 60; done &

and closed the terminal to test it, now I got the same problem.

If you already closed the terminal you've started the loop in

Let's get an overview of running processes with ps fjx, the last lines on my machine read

 2226 11606 11606 19337 ?           -1 S     1000   0:00  \_ /bin/bash
11606 22485 11606 19337 ?           -1 S     1000   0:00  |   \_ sleep 10
 2226  9411  9411  8383 ?           -1 S     1000   0:00  \_ /bin/bash
 9411 17674  9411  8383 ?           -1 Sl    1000   0:00      \_ yad
    1  2215  2215  2215 ?           -1 Ss    1000   0:00 /lib/systemd/systemd --user
 2215  2216  2215  2215 ?           -1 S     1000   0:00  \_ (sd-pam)

You can see yad as a subprocess of /bin/bash, if I close yad it changes to sleep 60 in the output of ps. If the tree view is too confusing you can also search the output as follows1:

ps fjx | grep "[y]ad"  # or respectively
ps fjx | grep "[s]leep 60"

The output lines begin with two numbers, the first being the PPID, the process ID of the parent process and the second being the PID, the ID of the process itself. It's because of that 9411 appears in both rows here:

2226  9411  9411  8383 ?           -1 S     1000   0:00  \_ /bin/bash
9411 17674  9411  8383 ?           -1 Sl    1000   0:00      \_ yad

That's the bash subshell we want to kill and we just found out its PID, so now everything that remains is a simple

kill 9411  # replace 9411 with the PID you found out!

and the annoying subshell is gone for good.

1: The notation as grep "[y]ad" instead of simply grep yad prevents the grep process itself from showing up in the results list.

If you have the terminal still open

bash provides the variable $!, which “expands to the process ID of the job most recently placed into the background”, so the following just kills the latest process in the background:

kill $!

If it's not the latest process, just can get a list of running jobs with the jobs builtin, example output:

[1]-  Running                 while true; do
    yad; sleep 60;
done &
[2]+  Stopped                 sleep 10

There are two jobs in the job list, to kill one of them you can access it with the job number or the shortcuts %, %+ (“current job”) and %- (“previous job”), e.g. to kill the loop running in the background you could do

kill %1  # or
kill %-

and to kill the suspended sleep 10 job:

kill %2  # or
kill %+  # or
kill %


How do I fix laptop speakers popping when no sound is playing?

I suspect it is the power save mode kicking into action which is causing the popping sounds.  Save the following into a file called audio-power-save-off

#!/bin/bash
for dev in /sys/module/snd_*; do
        [ -w "$dev/parameters/power_save" ] || continue
        echo 0 > "$dev/parameters/power_save"
done

and do the following:

chmod +x audio-power-save-off
sudo ./audo-power-save-off

and see if it helps


At the suggestion of my colleague @heynnema, let's try, with a temporary working internet connection:

sudo apt update && sudo apt install -y git
git clone https://github.com/ulli-kroll/mt7610u.git
cd mt7610u
make
sudo make installfw
sudo insmod mt7610u.ko

We anxiously await your good report.


Ctrl+Alt+Arrow up/down LIbreOffice Writer vs Workspace

You can disable the Ctrl+Alt+Arrow keybinding and use the alternative keybinding Super+Arrow (or define your own) to switch workspaces. That way, the keybindings are not anymore intercepted by the Shell, and will work in Libreoffice.
You can use dconf-editor (not installed by default) to change the keybindings using a graphical tool, but it is much faster and more precise to change the keybindings using commands:
gsettings set org.gnome.desktop.wm.keybindings switch-to-workspace-up ['<Super>Page_Up']
gsettings set org.gnome.desktop.wm.keybindings switch-to-workspace-down ['<Super>Page_Down']
gsettings set org.gnome.desktop.wm.keybindings move-to-workspace-up ['<Super><Shift>Page_Up']
gsettings set org.gnome.desktop.wm.keybindings move-to-workspace-down ['<Super><Shift>Page_Down']

This removes all Ctrl+Alt+Arrow combinations for switching workspace and moving windows between workspaces, leaving only Super combinations.
To undo, i.e., reset to default, use reset in the commands above and leave out the key definition.


In my Ubuntu 16.04, the low version zim will damage my maintained notebook folder?

Zim works based on a hierarchical structure of your notes in plain text files with some markup. At first run, it indexes these text files and stores the index in a sqlite3 database in a hidden .zim directory in the top-level folder of the notebook.
This design ensures that your actual data and folder structure will not be damaged trying to open it with a previous version. At most, you may need to reindex the data: use "Tools - Update index".


Device Browse using Bluetooth not working in Ubuntu 11.10

If you use backports, then just purge package linux-backports-modules-cw-3.1-oneiric-generic

sudo aptitude remove linux-backports-modules-cw-3.1-oneiric-generic

and reinstall kernel

aptitude reinstall linux-image-generic

Now reboot.
It's working for me.


You should boot from an Ubuntu live-cd or something like supergrubdisk to install GRUB in the correct location.

For some more information, you could check out this wiki page which contains a few other possibilities and general useful information.


After disabling Touchpad from system settings it disappeared 18.04

i used this to solve the issue: gsettings set org.gnome.desktop.peripherals.touchpad send-events 'enabled'
but still even after it comes back, if you disable from the settings pane, you have to use gsettings again to make it work!


How to run a program for a fixed period of time?

Why not use /usr/bin/timeout?

$ timeout --help
Usage: timeout [OPTION] DURATION COMMAND [ARG]...
  or:  timeout [OPTION]
Start COMMAND, and kill it if still running after DURATION.


A strange account appear at login to Ubuntu 12.04?

There's a bug in the last Ubuntu where service accounts that are disabled for login, show up in the login screen. For instance, in mine the user Postgres appears since I installed postgresql service (database system).

Check if the user really exist by listing the home directory:

ls /home/

If there's not something like /home/student maybe the user is one of those service accounts. You can check them with users-admin:

sudo apt-get install users-admin
users-admin

May I add, in my case, this phantom user also shows up under the users menu on the top left of the Unity panel.


Viability of using "CMT" touchpad drivers on desktop

I found a PPA for Ubuntu with this driver, you could use this to test it, if something does go wrong, it is easy to remove from a PPA

sudo add-apt-repository ppa:hugegreenbug/cmt
sudo apt-get update
sudo apt-get install xf86-input-cmt
sudo reboot

The PPA also contains the dependencies libgestures libevdevc so it should work out of the box.

If you face any issues, just remove the driver like this

sudo apt-get purge xf86-input-cmt

From what I can see this is tested and working on Chromebooks with Ubuntu, although not by me.

Here is a link to the repository


When installing such application, its better to Visit the application website and get proper instrucions. So its better you to visit www.trimaran.org and Read the software requirements and Follow the installation manual


Does LibreOffice encrypt password-protected files

LibreOffice uses the OpenDocument Format which is a zip encrypted archive containing mainly xml files representing the document.
If you set a password to read the document, all those contained files inside the zip archive will be encrypted separately, except the metadata which remains as clear text.
Up to LibreOffice 3.5 (up to ODF 1.1), the Blowfish algorithm is used for encryption, current versions use AES-256 instead.
Here are some resources providing further details:

From http://listarchives.libreoffice.org/global/users/msg15359.html:

Saving a document with password is indeed an encryption. The encryption methods are specified in the ODF Specification for encrypting the parts of the Zip package. (There is no ODF-specified encryption for the single- XML-file form of an ODF document.)
The default method, that works for all ODF 1.0/1.1/1.2 documents in packages (e.g., ODT, ODP, and ODS files), is by Password Based Key Derivation (PBKDF2) using HMAC and SHA1 starting with an SHA1 digest of the UTF-8 user-chosen password. The encryption with the derived key is Blowfish with 8-bit Cipher Feedback (8-bit CFB). This is done on each file of the Zip package that carries the parts of the ODF document. (Each part has a different, randomly-derived initialization vector, but the derived key is the same for all of them.)
Starting with ODF 1.2, additional encryption methods can be chosen. However, there are interoperability issues if the document is intended to be opened with anything but the computer and software that was used to encrypt it (actually a common use case but not when secure interchange is intended).

From https://wiki.documentfoundation.org/ReleaseNotes/3.5#Different_Encryption_Algorithm:

In LibreOffice 3.5, a different and more secure encryption algorithm (AES-256) is used for password protected files in the ODF 1.2 and ODF 1.2 Extended file formats. The new cipher is activated by default. Blowfish encryption in ODF 1.2 files is considered deprecated

From https://en.wikipedia.org/wiki/OpenDocument_technical_specification#Encryption:

When OpenDocument file is password protected the file structure of bundle remains the same, but contents of XML files in package are encrypted using following algorithm:

The file contents are compressed with the DEFLATE algorithm.
A checksum of a portion of the compressed file is computed (SHA-1 of the file contents, or SHA-1 of the first 1024 bytes of the file, or SHA-256 of the first 1024 bytes of the file) and stored so password correctness can be verified when decrypting.
A digest (hash) of the user entered password in UTF-8 encoding is created and passed to the package component. ODF versions 1.0 and 1.1 only mandate support for the SHA-1 digest here, while version 1.2 recommends SHA-256.
This digest is used to produce a derived key by undergoing key stretching with PBKDF2 using HMAC-SHA-1 with a salt of arbitrary length (in ODF 1.2 – it's 16 bytes in ODF 1.1 and below) generated by the random number generator for an arbitrary iteration count (1024 by default in ODF 1.2).
The random number generator is used to generate a random initialization vector for each file.
The initialization vector and derived key are used to encrypt the compressed file contents. ODF 1.0 and 1.1 use Blowfish in 8-bit cipher feedback mode, while ODF 1.2 considers it a legacy algorithm and allows Triple DES and AES (with 128, 196 or 256 bits), both in cipher block chaining mode, to be used instead.


Unable to execute the laravel command "laravel new myapp"

Perhaps your missing a global install of laravel with composer:
Now run composer -version from a terminal, if you don't see a version printed out then start there.  Install it using this link. If composer is there check if laravel is installed globally, run laravel -version from a terminal you should see something similar to this:
Laravel Installer version 1.3.3

Now if that doesn't appear then it's not installed, install using:
composer global require "laravel/installer"

Now add composer to your system PATH so you can run laravel command. Open your /home/$USER/.bashrc file and this line export PATH=$HOME/.composer/vendor/bin:$PATH to it.
Steps:

Open .bashrc with nano:
 nano /home/$USER/.bashrc

Add this line export PATH=$HOME/.composer/vendor/bin:$PATH.

UPDATE: On Ubuntu 18.04 the line should be export PATH=$HOME/.config/composer/vendor/bin:$PATH

Source the file with source /home/$USER/.bashrc

Now run laravel -version from terminal to ensure all went well. At this point you can now run the laravel command to create applications.
Source:
Install laravel 5 on Ubuntu 16.04
https://laravel.com/docs/5.4#installing-laravel
UPDATE
Since your still seeing that error simply install that extension with:
sudo apt install php7.0-zip

Now run that laravel command again.


Mount from rc.local fails; how to do it properly?

The problem must be that at boot time your network isn't available yet, and it's the reason why it mounts after boot. You must use another mechanisms to mount the device, like upstart. Example using upstart:

# mount CIFS share

start on (local-filesystems and net-device-up IFACE!=lo)
stop on runlevel [!2345]

pre-start script /bin/mount /mnt/mediaDrive
pre-stop script /bin/umount /mnt/mediaDrive

You can modify it to suit your needs. The file name must end with .conf and saved in the /etc/init directory.


How to partition disk in Ubuntu and then install Windows 7?

You can use gParted to partition your harddrives.

To make a new partition, first shrink an existing partition (if you don't have enough unallocated space). The remaining space would be turned into unallocated space. Then you can make a new partition in that space.

Here is the tutorial for gparted: http://www.addictivetips.com/ubuntu-linux-tips/use-gparted-to-manage-your-disk-partitions-in-ubuntu-linux/

After that, you can normally install your Windows. But you won't be able to boot back into Ubuntu as the GRUB, needed to boot Ubuntu, would be replaced by the boot loader of Windows.

You would need a Live USB/CD/DVD of Ubuntu. After installing Windows, boot with any Live media. Open up a terminal and run the following commands:

sudo grub-install /dev/sda
sudo update-grub

Note that here /dev/sda is the name of the harddisk. To check the name of your harddisk run sudo fdisk -l. You'll see several names like /dev/sda1, /dev/sda2, etc. These are the names of the partitions, but /dev/sda is the name of the disk.


What process is used under the covers to load the Ubuntu Linux kernel?

Booting the Ubuntu Linux kernel From Disk For Traditional i386 and amd64 Architecture Computers Without EFI

Modern desktop and laptop computers with the EFI feature. As opposed to the traditional BIOS systems used for more than 20 years these systems virtually have an operating systems in their firmware--capable of loading substantial software items in one go. Furthermore these can be started on the computer with more security in the face of attacks by software that has somehow acquired the ability to store startup software.

More traditional hardware has less firmware and starts little-by-little. Those systems, described here, run self-tests in their firmware and then start off the boot process.

Here's the firmware code that booted the first PC's from floppy diskette (after the diskette sub-system was reset):

   MOV AX,201H
   SUB DX,DX
   MOV ES,DX
   MOV BS,OFFSET BOOT_LOCN
   MOV CX,1
   INT 13H
   JNC H4

What followed was error handling (4 retries) starting with resets.

H4 was located a little bit earlier and was:

   JMP BOOT_LOCN

The BOOT_LOCN was defined as location 7C00H

[1] IBM PC Technical Reference Manual (1984)

There's not much there to get your system started. The first sector of the storage media, the Master Boot Record, is read into the computer's memory at location 0:7c00 and then execution jumps to its start.

It's said that boot refers to picking oneself up by your bootstraps. There's a thin string of events that must take place correctly to get your system started. Once enough code has been loaded from disk and started the system can provide things like error messages, prompts, and error handling. A single sector doesn't have enough room for any of that complexity.

By the way, eventually the code changed a bit. The high order byte of DX was set to 80H to refer to the first disk rather than the first diskette. Of course still later additions to a PC's BIOS incorporated bent geometry and packet-based I/O for larger sector addresses and the ability to allow it to boot from CD's, over USB, etc. The idea on traditional PC hardware is still the same, read the first sector and transfer control.

Other than that not much happened until EFI.

It's up to that first sector to find what should happen next and load at least its first sector, then up to that sector to load several sectors--and your system should then be off and running. That's how modern Ubuntu systems boot on almost-modern hardware.

MBR

Sources:
http://bazaar.launchpad.net/~ubuntu-branches/ubuntu/utopic/grub2/utopic/view/head:/grub-core/boot/i386/pc/boot.S

The first sector is the MBR and the next sector is the first part of Grub2. I should add that the four primary partitions are also defined in the MBR, and one of those can describe a region of the disk containing a chain of extended partitions. The first sector's address is sector 0.

What can go wrong:
If Windows is installed or reinstalled after Grub, it can replace The Grub MBR code with its own. With that the pointer to the Grub code is gone and the new Windows code will search for a partition with the Boot flag, loading a sector from its beginning and transferring control to it.

In a usual installation the remainder of the core of the grub code follows directly and the Grub MBR points to the next sector, sector 1. If you install Grub to a partition the pointer may get changed. That grub pointer is in 0x5c-0x60 of the MBR and must be changed correspondingly.

00000050  f7 c1 01 00 74 03 fe 46  10 66 00 80 01 00 00 00  |....t..F.f......|
                                               ^

The largest sector number that 4 byte pointer will hold is 2^32, 2,294,967,296 sectors, or less than 2.2 x 1012 bytes. The following grub code must be within that part of the disk.

Grub2 core.img Start

Sources:
http://bazaar.launchpad.net/~ubuntu-branches/ubuntu/utopic/grub2/utopic/view/head:/grub-core/boot/i386/pc/diskboot.S

Usually starting at sector 1 (if you installed Grub2 to /dev/sda, for example) are the parts of the core.img. The whole image must be loaded for grub to give you a prompt. At the very end of its first sector is a blocklist, a list of sectors and counts from which the rest of the image must be loaded. Unlike the MBR there is enough room in the sector to load multiple sets of multiple sectors. Now we are getting somewhere. Sectors are positioned every 0x200 bytes. Each extent is described in 16 bytes.

         |
00000360  00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00  |................|
00000370  00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00  |................|
00000380  00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00  |................|
00000390  00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00  |................|
000003a0  00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00  |................|
000003b0  00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00  |................|
000003c0  00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00  |................|
000003d0  00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00  |................|
000003e0  00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00  |................|
000003f0  00 00 00 00 02 00 00 00  00 00 00 00 63 00 20 08  |............c. .|

What can go wrong:
GPT formatted drives have the partition descriptors located starting on the second sector. In that case the grub image must be located somewhere else in a partition. It would probably be best to format a small partition just for grub to hold its core image. Place it somewhere close to the beginning of the disk where you won't be tempted to move or disturb it. It mustn't be moved without re-installing grub to it.

If something, like a whole disk encryption system was installed in this location it is wiped out. It probably has to be there to boot your system or to access your data. Ouch.

If you later install encryption or other software that uses this area for some of its contents core grub will no longer start.

The blocklist reserves 2 long words for sector number, so every bit has to be stored within 2^21 terabytes of the beginning of the drive. That should be good enough for a while. Much of what it loads is compressed. Older systems had space between the MBR and the first partition of only 1 track - 1 MBR sector. This might be about 63 sectors and 63 sectors is what Ubuntu 14.04 loads at this writing. The compression is so that the whole grub kernel in the image can fit, along with a couple of handy grub modules. This will comprise the whole grub system when it first starts.

lzma_decompress.image

Sources:
http://bazaar.launchpad.net/~ubuntu-branches/ubuntu/utopic/grub2/utopic/view/head:/grub-core/boot/i386/pc/startup_raw.S
http://bazaar.launchpad.net/~ubuntu-branches/ubuntu/utopic/grub2/utopic/view/head:/grub-core/boot/i386/pc/lzma_decode.S

This is the beginning of what is loaded by the last step, and typically is in sector 2, the third sector.

The whole core image is now all loaded. This part takes the rest of the information following it and uncompresses it in memory.

Grub2 Start

Sources:
http://bazaar.launchpad.net/~ubuntu-branches/ubuntu/utopic/grub2/utopic/files/head:/grub-core/
http://www.gnu.org/software/grub/manual/html_node/index.html

At this point a substantial amount of Grub2 code is loaded and uncompressed. This code includes a couple of modules as long with the grub2 kernel. Sort of appearing like a module is a short segment containing the grub prefix. This is a string like:

(hd0,msdos5)

When grub starts, if you enter the c key you can enter a grub command, if you do that and enter the set command you can see what prefix was set when your Grub2 code was installed on your disk. (Press ESC to go back).

Grub can now access, and navigate through, many kinds of file systems and the prefix is key to where it will start to look.

From the directory described by the prefix grub loads the grub.cfg file. This file is (re-)created by the update-grub command which find all the places you may want to boot from, and specifies these in the menu structure defined by the file. The file also specifies if the grubenv file should be loaded. That file loads a grub2 environment, possibly including, for some grub configurations, the last successfully loaded boot menu. The grub.cfg file also directs the loading of more grub modules from the same directory.

grub can now display a menu if there are choices to be made.

When you select an item from the menu that item is used to run the grub commands in that menu entry. These may load further modules necessary to deal with the kernel and initrd image at the location referred to by that menu item.

The final commands of the menu item are of particular interest.

The linux command specifies the linux kernel grub is to load, and the linux boot command that should be passed. Of special interest in the Linux kernel command is the root= parameter. It will tell the kernel, in the kernel's terms rather than in grub's, what partition should be mounted as root.
The initrd command specifies the location of the matching compressed cpio initramfs file (called initrd.img-version) that contains an in-memory file tree containing extra information the linux kernel needs to start up, and kernel modules it may need.
The boot command then transfers CPU control to the loaded kernel for it to start up.

What can go wrong:
If the prefix is wrong, grub will not start properly, and cannot load a menu or appropriate modules. This can be caused if partitions are reordered or previous partitions deleted, changing the partition numbering. It can also be caused if the information in the specified partition has been changed. It should always match what is stored by grub-install, which was given a particular directory to install from. If the actual grub code is changed on the partition from which grub is working grub should probably be reinstalled on the drive with grub-install. Even so, if you can find the correct partition you should be able to manually set the prefix and get grub to work.

Things to know when running Grub2:

Enter the command pager=1 to avoid items rolling off the top of the screen.
Enter the command debug=all to put out debugging messages to give you extra information about what is happening as you enter commands.

Kernel Boot

That kernel initialization up begins generically and is described in books, etc. After a bit it refers to Debian and Ubuntu specific information in the initrd file system image. In part: the partition designated for the root directory is found, checked if necessary, and mounted for writing, the in-memory log is copied to it, and upstart is run. Upstart takes over system initialization, including running the traditional scripts in the /etc/rc.#/ directories in its /etc/init/rc-sysinit.conf job.

What can go wrong:
Perhaps the most frequent grub-introduced problem is that the root= kernel command passed from grub to the kernel is wrong. This can cause an early halt in the initialization of the kernel with a busybox prompt as the root of the desired system can't be found.

[1] IBM Personal Computer Hardware Reference Library: Technical Reference; Part number 6361453 (1984), Page 5-50 (for the IBM 5150 Personal computer, the only "PC™" at the time)
http://www.minuszerodegrees.net/manuals/IBM_5150_Technical_Reference_6322507_APR84.pdf page 143


That is not an error; it is a notice. tar archives have relative paths so this is correct behaviour: when you "untar" the file you provide the command with a place it should extract and in case of absolute paths it will install it into the root directory regardless of what you told it should use as a path. Makes the untarring illogical.

See man tar and the P option if you want absolute paths (but please do not).

 -P, --absolute-names
       don't strip leading '/'s from file names


Why do I need to install Nvidia driver for Flatpak applications?

Flatpak applications run in a sandboxed environment, where they can't access the outside world. That's why a separate copy of the driver needs to be installed.

Due to the fact it's sandboxed, it won't replace the system driver. It just supplements it.


You can update the driver to the latest version by

sudo apt purge bcmwl-kernel-source
sudo apt install broadcom-sta-dkms

It will update the wl driver from 6.30.223.248 to 6.30.223.271.

But I am not sure that it can seriously improve anything. But it can, since Broadcom released this new blob for some reason.

As far as I know, there are no other drivers supporting this device on Linux.


a sub-net mask of /20 means that the two IP addresses you mention are in the 172.16.16.0/20  sub-net not the 172.16.0.0/20 sub-net.

You should not include /etc/bind/zones.rfc1918 first in your /etc/bind/named.conf.local file, but rather after your own reverse zone declarations.

To answer your actual questions: I suppose it might be possible to edit /etc/bind/zones.rfc1918 directly, but no it would not be good practice.


In Ubuntu, Should I update the Chrome Browser through the browser or the system's package manager?

"purge" will remove everything including settings.

just like how they would be deleted if you used the package manager to update chrome

No, apt never uses purge automatically. It uses "apt remove".
Chrome is not part of a default install and if it is in the apt repository then you are using a 3rd party repository. So... either method will use the same method to update: either from an update through that repository or by adding a new repository where it disables the old one.


Signature by key C47415DFF48C09645B78609416126D3A3E5C1192 uses weak digest algorithm (SHA1)

Those warning messages can just be ignored. All repositories used to use SHA1 signatures, but it was found that SHA1 had problems, and they're converting over to SHA256 type of signature. Not all repositories have completed that transition.

If somebody can provide more technical details, please chime in.


Can't login to GUI, only to tty1-6, /bin is not included in the PATH environment

Log in on a tty1 (Ctrl+Alt+F1) and run these commands:

export PATH="/usr/lib/lightdm/lightdm:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games:/usr/local/games:$PATH"
sudo chown -R $USER:$USER /home/$USER/

You can replace $USER with your actual username.

Now, try logging in again.


Is a block size of 4 MiB on a partition of 99.06 GiB too big?

It depends on size of whole drive. If your drive is bigger than 750 GB it is highly recommended to use block size 4 MiB. Otherwise, you can use smaller, for example 500 KiB.


When will xrandr version 1.5.1 be available in Ubuntu?

Actually, unlike libXrandr.so.2, the xrandr program is far from being mission-critical. It's just an X client — an unprivileged app you could install into your home directory to avoid clobbering the system one. Here's how you could do it (as a normal, non-root user!):

cd ~/Downloads
wget https://xorg.freedesktop.org/archive/individual/app/xrandr-1.5.1.tar.xz
tar xvf xrandr-1.5.1.tar.xz
cd xrandr-1.5.1
./configure --prefix=$HOME/opt/xrandr/
make install

For the compilation to work, you have to have installed the build dependencies: namely, the following command should do it.

sudo apt build-dep x11-xserver-utils

Then you can just launch it from the install directory:

$ ~/opt/xrandr/bin/xrandr --version
xrandr program version       1.5.1
Server reports RandR version 1.5

Or you can prepend $HOME/opt/xrandr/bin to your PATH and launch it as you normally launched the system xrandr. Once you are sure it works as you need, you can replace the system /usr/bin/xrandr (maybe having backed up it), so that any other users run it by default.

If you do replace the system binary, don't forget to hold corresponding package (on Ubuntu 16.04 it's x11-xserver-utils) to prevent updates from replacing it with an (most likely) earlier version.


Ubuntu 12.04 2D mode after upgrading my Nvidia graphic driver

First remove all Nvidia packages (if you haven't done so already):

sudo apt-get purge nvidia*

Then install the current Nvidia drivers:

sudo apt-get install nvidia-current

Reboot, and you're good to go.


The default fonts you're disatisfied with are those which are set within your browser, and overriding the system fonts may not be the best approach. If you are using Firefox there are font setting preferences, and if using Chromium you will need to install an extension. You can then preview and choose your preferred fonts in a more flexible way. To get the Microsoft default system fonts in Ubuntu, install the package ttf-mscorefonts-installer via your preferred method (ie apt in a terminal, synaptic, or otherwise) to get Arial. As an alternative to Arial, I also recommend the fonts-texgyre package, with TeX Gyre Heros as the best free Helvetica alternative (actually a highly developed and extended set of Nimbus, a grotesk which has a history prior to Helvetica).

More specific to your situation, the diagonal stroke thinning on the "S" and "s", as well as the compressed counters and narrowed aperture in "e", and too-low middle stroke of the "E" seems to indicate that you are using the infinality package. To my taste, this package is very unsuited to the default tweaks Ubuntu is already applying to the freedesktop font rendering, and much better for most other distros (like Fedora or OpenSUSE). Basically, it's correcting in addition to the corrections that are built into Ubuntu by default, rather than replacing them. I think the Ubuntu defaults are the best font rendering on any desktop operating system, but if you are a long-time Windows user they will look very different (much less strongly aliased). I recommend uninstalling infinality if you do have it on an Ubuntu installation, and if you want to try a tweak, use unity-tweak-tool to turn font hinting off completely (allowing the renderer to make all the decisions itself).

Some example screen shots of Youtube at different magnifications, in Chromium. Note that changing system hinting preferences in unity-tweak-tool (and logging out and back in to restart the session) did not change the rendering of these tiles in-browser.

Roboto (Youtube default, to compare with OP's screenshot):

Roboto (size decreased as a test of the compositor's aliasing capabilities):

Arial (as alternative font) this is with hinting turned off completely, RGBA aliasing. The font renders in a very crisp, MS way.


For version look at this post. For graphic driver look at this pages from Ubuntu documentation:

For Nvidia
For AMD


virt-install using location with iso image no longer working

@Programster - I reported this issue to the virt-manager maintainers on their mailing list.  See http://www.redhat.com/archives/virt-tools-list/2016-August/msg00009.html. You can follow that thread for more details. Knowing that this worked in Ubuntu 14.04 and not in Ubuntu 16.04 was key to resolving the problem.

Bottom line, this is fixed now in the master branch of https://github.com/virt-manager/virt-manager.

The commit that fixed it is: https://github.com/virt-manager/virt-manager/commit/3f15a489cda87f8028828d567848193dd2640a43

I'm not sure when this will make it into the various virt-manager packages. But you can grab the source and run virt-install from there. (Note: you'll need to add some packages, and probably should create a Python virtual environment, so you might want to experiment on a VM before messing about with extra packages on a system you need to remain stable and clean.)


z.Z. kannst du die "nomodeset" option beim booten nutzen.

im Grub Menü Taste "e" drücken
nomodeset an der richtigen Stelle einfügen (s.h. ubuntuusers nomodeset)
"F10" drücken
bei jedem bootvorgang

oder dauerhaft in /boot/grub/grub.cfg eintragen
bis die Inteltreiber aktualisiert wurden.

currently you can use the "nomodeset" option when booting.

Press the "e" key in the Grub menu
Insert nomodeset in the right place (see ubuntuusers nomodeset)
Press "F10"
with every boot process

or enter it permanently in /boot/grub/grub.cfg
until the Intel drivers have been updated.


Should I enable backports repositories on Ubuntu Server (LAMP)?

If you are happy with your current setup and want stability then backports are not for you but if you want cutting edge for some reason, then enable them, I wouldn't on a server.


AndroidStudio install on Chromebook - crouton-Skript Ubuntu14.04

I don't think this is currently possible as Android SDK is not available pre-compiled for ARM, only for x86(64) architecture.
In theory, Android Studio should work as its Java, but I suspect it has native executable (.so) library dependencies as well as they would need to be recompiled for ARM as well trying to run Android Studio on a HP Chromebook 14 (Tegra K1 based) with ubuntu installed crouton and openjdk installed via apt just causes the java exe to stop - not error message or segfault, just does nothing.


I am confused, I download ubuntu into my windows 8 laptop and cannot get ubuntu to start,

It sounds like you need to reboot the computer and boot into Ubuntu from the DVD.  See: https://help.ubuntu.com/community/LiveCD#Using_your_LiveCD

The Live-DVD will let you try Ubuntu directly from the DVD and will provide an icon with which Ubuntu can be installed on your computer.


You do something like:

// Main.qml
MyItem {
    id: thisIsMyItem
}
Button {
    onClicked: console.log(thisIsMyItem.name)
}

The idea is that you can use the components you declared in the same document referenced by their id. You call these files "documents" in QML.

Another thing is that you don't need to use the myItem id in MyItem.qml, you can simply reference the name property with its name. Of course, using the id is necessary when you have multiple components in the same document with the 'name' property.

// MyItem.qml
Item {
    id: myItem
    property string name: "Myself"
    Item {
        id: secondItem
        property string name: "Second Item"
        Component.onCompleted: console.log("This item's name is " + name + ", and parent item's name is " + myItem.name)
    }
}

One remark: that onClicked in your MyItem.qml would give a syntax error, as Item has no clicked() signal.

Hope this helps.


How can I resize dash app icons on Ubuntu 18.04?

In nautilus, the minimum size of 48px is hard-coded within their software. The setting that control this is:

You can see by running this command it's already set to small, so it can't get smaller:

gsettings get org.gnome.nautilus.icon-view default-zoom-level

Now, depending on your preference, you can set the zoom level by altering the value within the quotes from the list of values listed below

gsettings set org.gnome.nautilus.icon-view default-zoom-level 'value'

small
standard
large
larger
largest

For fine grain control, use

gsettings set org.gnome.nautilus.icon-view thumbnail-size 100

Replace 100 with your desired size


Is there an Anglicized transliteration IME for typing Arabic?

The Buckwalter Arabic transliteration is available in 11.04 at least for Egypt and Syrian Arab Republic keyboard layouts, so go to Keyboard Preferences > Layouts > Add... and then pick Country: Egypt and Variants: Arabic Buckwalter, and give it a try. I don't know if there are regional differences between the same variant in different countries.


Rename *FINAL.mkv to *.mkv keeping original "*"

Assuming the word FINAL comes only once in the filenames, you can do:

rename -n 's/FINAL//' *.mkv

This will do the dry run. After being sure you can carry out the operation :

rename 's/FINAL//' *.mkv


The default file manager in Ubuntu is Nautilus.

And yes, you can install dolphin in Ubuntu. As you can install any Kubuntu software in Ubuntu by installing the package as you would with any other piece of software.

Good idea? Not really. Since you will be mixing 2 operating systems there is a lot of overhead (libraries that do the same for a specific program are installed twice for each operating system).

Installing dolphin from the software center:

and you can also tick the "add-ons" if you want.


Upgrade Ubuntu 16.04.1 from 14.04, no desktop appears

After upgrading from 14.04 to 16.04.1 I got the exact same problem. Just start your Ubuntu and press Ctrl+Alt+F1 to enter on console and then download and re-install the package libstdc++6_5.3.1-14ubuntu2.1_amd64.deb via dpkg -i :

wget http://launchpadlibrarian.net/259210936/libstdc++6_5.3.1-14ubuntu2.1_amd64.deb
sudo dpkg -i libstdc++6_5.3.1-14ubuntu2.1_amd64.deb

After that apt-get works fine, but I got some errors (due to mySQL and another installed libc). I try to remove those via apt-get remove which returns an error. Then I just run the command suggested by apt-get and now everything works fine.

Found the solution here: Upgrade from 14.04 to 16.04 dependency issues


It depends on what sort of USB connection you are talking about.  If your enclosure only supports USB 2.0, then the maximum speed you can talk to the drive will be 60 megabytes a second.  This is the maximum speed: if anything else is using that USB bus, then performance may be lower.

To put this in perspective, OCZ sells solid state drives with maximum speeds ranging from 250 megabytes per second (a slow, high capacity drive) to 550 megabytes per second (a high performance, lower capacity drive).

So a USB 2.0 enclosure is going to greatly constrain the performance of almost any SSD.  If you can't mount the drive internally, then an eSATA or USB 3.0 enclosure would be a better choice (assuming your system supports one of those connection methods.


How do I encrypt files after skipping the option during installation?

I use the following two encryption programs: truecrypt and openssl; the first allows you to create any size of encrypted container, and the second allows you to encrypt individual files; folders must be tarred before encrypting, as the target to be encrypted must be one single chunk of data.

Truecrypt is an excellent program, but is not available in the repositories, so you must go to truecrypt.org to download the program; you want the 'standard' version, and it is available in 32 or 64bit. After downloading, open the terminal and cd to the containing folder and enter tar -zxvf <truecrypt download file>, and then chmod +x <truecrypt setup file>, and then sudo ./<truecrypt setup file>.  (You need to use sudo as it will install to the system folders.)
Then follow the onscreen prompts and truecrypt will be installed. After that it is best to run it as normal user when you want to create a volume, but with gksudo when you want to mount a volume. (If you create a volume as gksudo, root will own it, and so you would have to chown it for your user to regain ownership.)
When creating a volume in truecrypt, there are a lot of options, and even whole usb flash drives, external hard drives, internal hard disk partitions, and more can be encrypted. Even though a long discussion of these aspects of the program is not relevant to this answer, there are several other important things to note. In particular, it can be useful to format the truecrypt volume's filesystem in FAT32. The volume will then be easy to open if the file is transferred to a Windows system, as a volume created with the FAT32 option will be able to be opened by the Windows truecrypt executable.
The volume truecrypt creates is in a sense similar to that created with virtualbox; i.e. a virtual disk with its own filesystem. There is good documentation on the site that explains in great detail how to use the program. Also, after installation the pdf guide should be in /usr/share/truecrypt/doc/TrueCrypt User Guide.pdf.
I also use openssl (installed as default) to encrypt various files and tarred archives. I use the same commands as given in this section of the Unix toolbox, but I repeat them here for completeness, credit to Colin Barschel. The first command encrypts; the second decrypts in both the files and the folder examples:

For files:

Encrypt:

openssl aes-128-cbc -salt -in file -out file.aes

Decrypt:

openssl aes-128-cbc -d -salt -in file.aes -out file

For tarred folders:

Encrypt:

tar -cf - directory | openssl aes-128-cbc -salt -out directory.tar.aes

Decrypt:

openssl aes-128-cbc -d -salt -in directory.tar.aes | tar -x -f -


systemctl status mysql says that the MySQL system database was not found. Did you delete it?
In any case you will need to recreate the database as it says using mysqld --initialize


HD .mkv files - any hope for improvement in 18.04

If you're concerned about a particular behaviour in a version you haven't installed yet, then you can download an iso of that version and install it to a USB key and run Ubuntu that way.

You can install packages in the demo and verify that drivers and things work the way you expect.

I can't speak to the specific concern about the N2870 other than to say that Intel made the active decision to merge their graphics drivers directly into the kernel tree recently which means that they are now built in to Ubuntu rather than requiring a separate install.  This means you should expect your graphics to work out-of-the-box and only need to install additional (in-tree) packages if you want something special like DRM or DVDCSS that are geographically controlled.


Adding "Boot to Windows 10" in Grub (Other Solutions Suck)

Have you try to boot with Boot-Repair live cd, and select the option

"Restore MBR" under Advanced Options?
Boot-Repair Option

Here you can get the 32/64bit version of Boot-Repair ISO: https://sourceforge.net/projects/boot-repair-cd/files/


What sort of a performance hit can I expect if I use Bumblebee and Wine with an Optimus laptop? Can I even use Bumblebee in ivy bridge?

The performance hit is much worse with Bumblebee. Bumblebee uses VirtualGL as bridge between the rendering on the Nvidia card and outputting on the Intel display. VirtualGL was made as a more general purpose program for splitting 3D rendering from displaying. It works, but the performance is not as good as a native solution.

Consider Eric Appleman's results on https://github.com/Bumblebee-Project/Bumblebee/issues/37#issuecomment-4062386. I also did a test on a GT 425M (Fermi) and that also showed a 10 times worse frame rate using glxspheres. The first command below used Bumblebee/VirtualGL, the second renders the program "natively" on the Nvidia card (although the program is not visible because there is no external monitor attached).

$ optirun glxspheres
Polygons in scene: 62464
Visual ID of window: 0x21
Context is Direct
OpenGL Renderer: GeForce GT 425M/PCIe/SSE2
72.460542 frames/sec - 75.205347 Mpixels/sec
74.386601 frames/sec - 77.204366 Mpixels/sec
75.740174 frames/sec - 78.609212 Mpixels/sec
74.906713 frames/sec - 77.744179 Mpixels/sec
75.722470 frames/sec - 78.590838 Mpixels/sec
75.897246 frames/sec - 78.772233 Mpixels/sec
76.254962 frames/sec - 79.143500 Mpixels/sec
76.083521 frames/sec - 78.965565 Mpixels/sec
$ DISPLAY=:8 glxspheres
Polygons in scene: 62464
Visual ID of window: 0x27
Context is Indirect
OpenGL Renderer: GeForce GT 425M/PCIe/SSE2
734.081618 frames/sec - 819.235085 Mpixels/sec
728.918580 frames/sec - 813.473136 Mpixels/sec
730.108078 frames/sec - 814.800615 Mpixels/sec
730.416062 frames/sec - 815.144325 Mpixels/sec
730.235888 frames/sec - 814.943251 Mpixels/sec
730.164017 frames/sec - 814.863043 Mpixels/sec

If you do not mind buying an external monitor and leaving the laptop screen black, you can take full advantage of the Nvidia card even if it is an Optimus laptop. The alternative is looking for Lenovo laptops, these have a BIOS option for choosing between the integrated and discrete card or Optimus mode. Other vendors can learn a lot from Lenovo in regard to that...

PRIME is the real solution to the Optimus issue (Bumblebee is more a workaround/hack), but it is likely not adopted soon by Nvidia due to licensing issues.

Ivy Bridge is unrelated to Bumblebee, whether that gives issues has more to do with driver support from Intel.


To list all sleeping process in your database

sudo /mysql_rms/bin/mysqladmin -S /mysql_rms/var/mysql_rms.sock -p processlist

Here you will get list of data , among that list the first field is pid.

To Kill all of them

sudo /mysql_rms/bin/mysqladmin -S /mysql_rms/var/mysql_rms.sock -p kill <id1>,<id2>

Id's are nothing but pid which was taken above. You can kill one after one or you can kill all of them at a time by appending them one after one by separating with comma (,).


WSL Ubuntu app on Windows 10 closes immediately

I reinstalled Ubuntu and that seems to have fixed the problem. The original problem did start when I was required to restart for a Windows update on my system. After the update I started having the above issue in Ubuntu. Now after reinstallation, it seems to be working fine.


What can I do when a Python virtual environment doesn't find modules?

With "pip list" you can always check which packages are installed in your venv.

(venv)user@home:~/venv$ pip list
pip (9.0.1)
setuptools (32.3.0)
wheel (0.29.0)
...


Overheating problem in Samsung NP550P7C Laptop

I've had issues like this with my laptop (Asus U46.) I switched to version 3.4 of the Linux Kernel and the laptop is heating much less (10 celsius degrees down compared to kernel 3.2)

Just an idea...


Ubuntu Server 16.04: connect to wifi network (usb wifi adapter)

To configure the wireless networks from the terminal you can use (nmcli)

sudo nmcli --help

man nmcli

You can also use (nm)

sudo nm-connection-editor --help

Goodluck


Problem installing Ubuntu 12.04 on Sony Vaio with Windows 8 and UEFI

First, I recommend you disable Secure Boot. Although Ubuntu theoretically supports Secure Boot, in practice it sometimes causes problems. Given the way you installed, though, this step alone won't solve your problem. I have two recommendations for how to proceed:

Download the USB flash drive or CD-R version of my rEFInd boot manager. You should be able to boot from it, and with any luck it will give you an option to boot Linux via an entry whose description includes the string vmlinuz. If this works, install the Debian-package version of rEFInd, which should make it your default EFI boot manager. If you can't boot to Linux from the rEFInd USB flash drive or CD-R, you may still be able to use it (see below), but try this only if the next suggestion doesn't help.
Run the Boot Repair tool from an emergency disc. This often fixes the problem, but sometimes it doesn't do any good, and on occasion it can even make matters worse. If it doesn't help, and if rEFInd also doesn't help, post the URL that Boot Repair gives you; this will give us detailed diagnostic information about your system.

If an EFI-mode boot is impossible, you may be able to use rEFInd to manage a switch between EFI-mode and BIOS-mode booting. You can test this with the USB flash drive version of rEFInd: Mount it and open the EFI/BOOT/refind.conf file in a text editor. Locate the line that begins #scanfor. Uncomment it (by removing the lading #) and add hdbios to the options. When you restart with rEFInd, you should see a new option with a grayscale diamond-shaped icon. This should launch your BIOS-mode version of GRUB. If this works, you can install rEFInd on the hard disk from Windows and change the disk-based version of refind.conf to get it working.


How to I enable jumbo frames on just one network interface?

The question is phrased like there's a way to globally turn it on. I'm not aware of that method, here's how I'd turn it on:

sudo ip link set eth1 mtu 9000

Or (as this is a server) if you're using the /etc/network/interfaces configuration, you can simply stick it in at the end like so:

auto eth1
iface eth1 inet static
        address ...
        netmask ...
        network ...
        broadcast ...
        gateway ...
        dns-nameservers ...
        mtu 9000

I suggest you test the MTU rate with ip before you persist it in /etc/network/interfaces. Oh and you'll need to run sudo service networking restart if you only used the second method there.

You can verify the configuration with ip:

ip link show eth1

And there are various things like traceroute --mtu that can measure and test that MTU.


Logitech dinovo edge Bluetooth dongle stop working after upgrade to 12.10

I have the DiNovo Cordless Desktop too, the old version (LZ845AG).

The problem reside in the dual mode functionality of the USB dongle. It is a full btusb dongle, but it has a second operating mode: it works as a (non-bluetooth) HID device.

This is neccessary if, for example, you want to enter BIOS with the keyboard. There is no bluetooth stack available at BIOS stage, so the dongle works in HID mode. Otherwise you could not use the keyboard in BIOS / DOS / any non-bluetooth environment, so the dual mode does make sense.

However, full functionality is somewhat broken (again) in 12.10., depending on your setup. I have tested 3 choices so far:

1.) You are working on a non-dualboot machine: No problem. Just bind the keyboard / mediapad / mouse once. Re-insert the stick if it does not work. Re-insert the stick while pressing the red button on the stick if it still does not work (this will force bluetooth mode manually). When the bluetooth icon finally appears on screen (top bar, left to the time clock): Press the red buttons one the devices, then use the bluetooth icon to add the devices, one by one.

2.) You are using a different usb dongle with the hardware: Works too, see above, but you need additional software on dual boot machines, e.g. for Windows. May be tricky there, but works for Ubuntu just fine.

3.) You have a dual boot machine and want to use the original usb dongle as well as the standard Logitech Windows software: At least with my DiNovo (old version) the problem is now that you are forced to re-bind all of the devices everytime you switch operating systems. There are rumours the newer DiNovo does not have this problem, but I did not find a way around it with my old DiNovo so far. Very sad, as the DiNovo is not the cheapest keyboard / mouse combo around at USD $180.

So everytime you switch, enjoy the hen and egg problem: Try to add keybard and mouse in Ubuntu without having keyboard nor mouse. Good luck. ;)

On older Ubuntu versions you could circumvent this by uninstalling the Logitech software in Windows and let the DiNovo run in HID mode under windows, and in Bluetooth mode in Ubuntu. For some reason, this does not work in 12.10. anymore.


mysql server is failing to get installed to my machine

AFAIK the package you are looking for is indeed mysql-server.

dpkg -l 'mysql*' should list possible candidates.

Otherwise what are your packages sources in /etc/apt/sources.list, and which Ubuntu version are your running?


According to https://launchpad.net/ubuntu/+mirror/mirror.biznetgio.com-release the PT. Biznet Gio Nusantara mirror is up-to-date for 20.04 again, however the latest libglu1-mesa package for i386 architecture is missing from this mirror.
The libglu1-mesa package for amd64 architecture is not missing from this mirror and an earlier version of the latest libglu1-mesa package for i386 architecture for Ubuntu 20.04 is not missing from this mirror either. The only thing that's missing is the latest libglu1-mesa package for i386 architecture for 20.04. If you prevented the libglu1-mesa package for i386 from updating with How to prevent updating of a specific package? you would probably be able to unhold this package and update it with sudo apt update in a few days. This would save you from needlessly downloading ~200MB of files which happens every time you switch download server mirrors.
The linked duplicate answer to the question would also work, but it would be like using a hammer instead of your thumb to push a thumbtack into a corkboard.


Changing visudo caused a problem with sudo

Since sudoers appears to be screwed up, you will have to first log in as root. To do this, simply type su -

You should then be prompted for the root password. After you log in as root, run:
visudo

After you're into the sudoers file, find the mistake and fix accordingly.

If you don't know the root password, then unfortunately you may have to "single" the host and reset it. If this is the case, do a search for "single user mode Ubuntu" and you'll find instructions on how to reset the root password.


How can I connect to the recovery console of a remote server?

I dont't think that you can access this server without IMPI or a solution by the one who has acccess to the hardware.