127.0.0.1:9051 doesnt work after apache, mysql, php installation?

Tor is neither HTTP proxy nor a web server, and under no motive it will run in port 80. The port 9051 is a control port which Vidalia uses to talk with Tor, while port 9050 is the SOCKS port where you should point your browser. I installed Apache, Tor and Vidalia and no problem arrises.

Vidalia and Tor should always communicate using localhost or 127.0.0.1. If localhost doesn't work, is probably because is preferring ipv6 and apache has nothing to do with it. In the control port type 127.0.0.1:9051 and restart the system. Don't autostart Tor yourself, Vidalia should bring Tor up when Vidalia starts. If you start Tor before Vidalia it will fail.


How to set my virtual box display for Red Hat Linux to 1366X768

With the virtual machine open, click on Devices --> Install Guest Additions.  See image below.


issue with vmd install not working any more. lubuntu 12.10

Ok here is how I fixed it.

I uninstalled rlwrap. hit

  make install

and then vmd ran!

Cheers.


Check in Settings Manager - Session and Startup.

That Automatically save session is not enabled

Then in Application Autostart you do not have an entry for the Applications you find starting.

Then you can clear any saved sessions from the Session Tab


Try installing the following packages + dependancies (worked for me on ubuntu 12.04):

libmono-microsoft-visualbasic10.0-cil
libmono-system-Data-Linq4.0-cil
libmono-system-xml-Linq4.0-cil


Ubuntu 14.04 black screen after switch GPU to nvidia at nvidia-prime

Because it's a relatively old post, I'm not sure if the problem still exists, but I still will provide a possible solution.
It seems you have both graphics adapters from nvidia and intel, which is called nvidia optimus.
So you might want to look at the package bumblebee, which was written for this.
 sudo apt-get install bumblebee
(type the above in a terminal, shortkey ctrl-alt-t)To use it, you have to provide optirun in front of the executable program (for instance in front of the executable in a terminal) to be able to use the graphic power of the nvidia card. Else, the intel igp will be used.


How can I automate a "conffile" prompt in unattended upgrades?

This appears to be the desired answer: https://unix.stackexchange.com/a/139554/5571

  I also want to keep original config files while doing automatic updates. You can add the following to /etc/apt/apt.conf.d/50unattended-upgrades

Dpkg::Options {
   "--force-confdef";
   "--force-confold";
};

  See here for a good explanation of the options: http://raphaelhertzog.com/2010/09/21/debian-conffile-configuration-file-managed-by-dpkg/


How to fix boot issue ? VFS: cannot open root device "mapper/x" or unknown-block(0,0)

Your most recent kernel, 3.5.0-47-generic, is missing its corresponding initrd image.  Pick the previous kernel version from the boot menu and once the system comes up, run sudo update-initramfs -c -k 3.5.0-47-generic to create the initrd, and sudo update-grub.


Minecraft 1.8.9 doesn't work, although 1.14.4 does

I would suggest trying to make a folder just for 1.8, in /home/blabla/.minecraft.
Run mkdir 1.8folder and change it in the Minecraft launcher.


Ubuntu NoRoot is an app available for Android phones.

  This app will install Debian or Ubuntu onto your device.
  You will need a mouse or stylus to use it.

  This app is NOT full Ubuntu OS - it is a compatibility layer, which allows you to run Ubuntu applications. This is NOT official Ubuntu.com release.

You can keep both OS the full version take 1.5 to 2 GB space you can download it from here.


Can't install Skype or update in Kubuntu 15.04

Enable the partner repository

How do I enable the "partner" repository?

Then update index by sudo apt-get update and use sudo apt-get install skype to install it.

The partner repository for main server in Trusty is like this one

deb http://archive.canonical.com/ubuntu trusty partner

You should change the trusty with vivid or your specific release name.


Only one processor core could be enabled according to dmidecode

Section 7.5.7 of the SMBIOS specification (http://dmtf.org/sites/default/files/standards/documents/DSP0134_2.7.1.pdf) states:

"Core Enabled is the number of cores that are enabled by the BIOS and available for Operating System use. For example, if the BIOS detects a dual-core processor, it would report a value of 2 if it leaves both cores enabled, and it would report a value of 1 if it disables multi-core support."

If you are seeing 4 CPUs online then I personally suspect that this maybe just a goof-up in the SMBIOS table.


It really depends on how much RAM you have. If you have more then 4 GB of RAM, and if it's Alienware, I'm assuming you do, then you should definitely install Ubuntu 64 Bit to take advantage of all of that RAM.


How to find a binary name with only the prefix?

You can list all the programs in the $PATH variable, search for the ones you want with grep and then sort numerically with the following command:

version=$(echo -e ${PATH//:/\\n} | while read line; do find "$line" -name "llvm-dll*"; done | grep llvm-dll | sed 's/[^0-9]*//' | sort -n | tail -n 1)
whereis $(echo -e ${PATH//:/\\n} | while read line; do find "$line" -name "llvm-dll*"; done | grep llvm-dll | grep $version) | sed 's/.*: \//\//'

The whereis command will give you the user's path to that command. Finally cut will only ouput the actual location of said command. I pulled the version number first so that the sort command can process it seperately. Otherwise, llvm-dll-10 would be sorted before llvm-dll-9

Edit: Added ls flags to prevent errors.

Edit: Made it space compatible.


try this WXCAM , I heard this is also one of the good software to get the webcam recording .


Managing large scale Snappy Core IoT deployment

snapd exposes a REST API locally, allowing anyone to communicate with the device. In reference to your questions-

You will need an agent on the device that talks REST with snapd.socket and uses whatever northbound protocol (that best suits your need) to communicate with your management agent in the cloud/on-prem.
You can upload your snap to the Ubuntu Core store. It allows you access to 4 channels- edge, beta, candidate and stable. Devices listening to the store can install a snap from any channel and will automatically track updates to that snap from that channel.
REST APIs will allow you to remotely monitor and reboot your devices (provided the device is online to begin with)


I mistakenly deleted php-fpm 7.0 pool.d/www.conf, how could I restore it?

I found a version that suited for me here:

https://gist.github.com/mustafaturan/3942448


These packages contain files that are part of the source code of the Linux kernel, available under /usr/src if you would like to take a look. They are just the makefiles and header files (file extension .h), which define the public API of the kernel, which is needed to compile programs that interact with the kernel directly (two examples that come up in internet searches are device drivers and virtualization software).

You have two versions because one is for your current kernel and the other is for an older kernel that you used previously. Ubuntu by default is very conservative with kernel-related files and takes a number of precautions to avoid removing them when they are still needed, and sometimes this results in a gradual accumulation of such packages as new versions are installed.


RFC7217 (stable privacy addresses) implementation in Ubuntu 16.10

I could be missing something but I don't see anything in the changelog that indicates to me that the RFC7217 support integrated into the network-manager for Xenial has been removed in Yakkety.

On 16.04 I get.

sudo sysctl -a | grep stable_secret
sysctl: reading key "net.ipv6.conf.all.stable_secret"
sysctl: reading key "net.ipv6.conf.default.stable_secret"
sysctl: reading key "net.ipv6.conf.eth0.stable_secret"
sysctl: reading key "net.ipv6.conf.lo.stable_secret"

On 16.10 I get:

sysctl: reading key "net.ipv6.conf.all.stable_secret"
sysctl: reading key "net.ipv6.conf.default.stable_secret"
sysctl: reading key "net.ipv6.conf.enp0s3.stable_secret"
sysctl: reading key "net.ipv6.conf.lo.stable_secret"

since the only difference I see here is a change in the naming for the NIC and furthermore there doesn't appear to be any change at /proc/sys/net/ipv6/conf/all/stable_secret I think it's logical to say Ubuntu 16.10 still implements support for RFC7217. While this is unset by default according to the kernel documentation

stable_secret - IPv6 address
    This IPv6 address will be used as a secret to generate IPv6
    addresses for link-local addresses and autoconfigured
    ones. All addresses generated after setting this secret will
    be stable privacy ones by default. This can be changed via the
    addrgenmode ip-link. conf/default/stable_secret is used as the
    secret for the namespace, the interface specific ones can
    overwrite that. Writes to conf/all/stable_secret are refused.

    It is recommended to generate this secret during installation
    of a system and keep it stable after that.

Further research indicates that since the release NetworkManager 1.0.4. the privacy extensions are turned on by default and  you can control them with ipv6.ip6-privacy property.

You can confirm that the version of your installed network-manager meets or exceeds that with the command dpkg -l network-manager

If anyone has found information to the contrary, drop me a comment as I'd be interested in seeing it!

Sources:

https://unix.stackexchange.com/questions/251401/cannot-read-key-net-ipv6-conf-all-stable-secret-in-sysctl/255955#255955

https://www.kernel.org/doc/Documentation/networking/ip-sysctl.txt

https://blogs.gnome.org/lkundrak/2015/12/03/networkmanager-and-privacy-in-the-ipv6-internet/

http://changelogs.ubuntu.com/changelogs/pool/main/n/network-manager/network-manager_1.2.6-0ubuntu1/changelog


User not appearing but exists, cannot give it sudo privileges

One thing comes to mind: GDM is patched in Ubuntu on Xorg to be started with /bin/bash instead of upstream's /bin/sh. Possibly fish isn't compatible with that configuration.


Set up rEFInd to boot Ubuntu directly (no Grub menu displayed)

Unless you have reasons for not using rEFInd's auto-detection that you've not mentioned, you're going about this the wrong way. Namely, you should rely on auto-detection for both the GRUB and direct-boot options. A default install with default options should definitely pick up GRUB automatically. This would be equivalent to your menuentry Grub option, except that the description and icon shown by rEFInd would be different. (You can easily change the icon in a number of ways, as described here.)

Depending on where your kernel is and how you installed rEFInd, your kernels might or might not be auto-detected. If not, the usual solution is to install an EFI filesystem driver for whatever filesystem holds your kernel. Drivers for ext2/3fs, ext4fs, ReiserFS, Btrfs, and a few on which your kernels will likely not appear all ship with rEFInd; and drivers for lots more come in the efifs package. Drop the appropriate driver in the drivers or drivers_x64 subdirectory of your rEFInd installation directory and rEFInd should be able to detect your kernels in their normal location. (Note that rEFInd 0.10.0 made some changes that help when using Btrfs; with earlier versions, you had to add @/boot to the also_scan_dirs line in refind.conf to detect kernels on Btrfs volumes. This is no longer necessary with rEFInd 0.10.0.)

Using auto-detection has some big advantages over what you're trying to do:

There's no need to manually copy your kernel; rEFInd should detect them from their normal "homes."
When you upgrade your kernel, rEFInd will auto-detect the newly-installed version with no need for re-copying the kernel or updating your configuration file.
It's easier. In most cases, auto-detection "just works," or works with minimal extra configuration. (You may need to run mkrlconf in Ubuntu to get the right kernel options to be used in some cases.) The manual initrd= option can be finicky (non-obvious typos and simple mistakes often wreak havoc), but auto-detection of the initrd file is typically flawless on Ubuntu systems.

The biggest disadvantage to auto-detection is that you can't control the name displayed as a prompt for the kernel. IMHO, this is a small price to pay for the advantages.

If you insist on doing it the way you're trying, the problem you're having is caused by the fact that, unless I've missed something, you've copied the kernel, but not the initrd file, to the ESP. The easiest way to get it to work is to copy both files to the same location. You must then specify the initrd file using the same path you use to refer to the kernel. For instance:

menuentry Ubuntu {
    loader /EFI/ubuntu/vmlinuz-3.19.0-31-generic.efi.signed
    icon /EFI/refind/icons/os_linux.png
    ostype linux
    options "root=UUID=92f926f7-19f8-4a2b-9e9a-bf91db475a3c ro"
    initrd /EFI/ubuntu/initrd.img-3.19.0-31-generic
}

Note that you should identify the initrd file either on the options line or on a separate initrd line, not both. (It would probably work with redundant specifications, but I can't guarantee that. At best, it could lead to confusion and/or extra work when you need to modify the settings.)


Press Alt+F2, type gksudo gedit /etc/default/grub press Enter and enter your password.
You will see the following contents:

GRUB_DEFAULT=0
GRUB_HIDDEN_TIMEOUT=0
GRUB_HIDDEN_TIMEOUT_QUIET=true
GRUB_TIMEOUT=10
GRUB_DISTRIBUTOR=lsb_release -i -s 2> /dev/null || echo Debian
GRUB_CMDLINE_LINUX_DEFAULT="quiet splash"
GRUB_CMDLINE_LINUX=""

You can change the default from 0 to any number, corresponding to the entry in the Grub bootup menu (first entry is 0, second is 1, etc.)
You can change the "hidden timeout" (no menu); and also display the countdown (TIMEOUT_QUIET=false)
You can force the grub menu to show by commenting out the two GRUB_HIDDEN lines with a # at the beginning of the line
And set the grub menu timeout (default is 10 seconds)
Make your changes, press Ctrl+S to save and Ctrl+Q to exit.
This will change your timneout
To change the order of your OS menu go to the directory /etc/grub.d

In this directory change the prefix of the Windows7 and make it less than of the Ubuntu one
- Important: Open a terminal with Ctrl+Alt+T and type sudo update-grub to apply the changes you just made.
- Reboot and you should see your timeout/default entry change.


There's nothing wrong. It's a normal message that shows to 'warn' you  that after this step your disk will be used entirely for the Ubuntu installation. This message appears every time an Ubuntu installation is done.


How can I install and uninstall themes in Ubuntu 14.04 .?

You can change your Ubuntu theme by going into

System Settings --> Appearance

Your custom themes are present in the ~/.themes directory  ( and  in /usr/share/themes/ unless you have not installed it as root user ) with their own name.

Simply deleting the folder (name of the theme you want to delete) will remove the theme.


How do I preserve the line ordering for two "equal" strings while sorting and ignoring the case?

I think you mean Stable sort. sort command does have a flag -s which does stable sort.

Snippet from sort manpage:

  -s, --stable
                      stabilize sort by disabling last-resort comparison

Output of sort fred -f:

END
START
test
tEST
TEST

Output of sort fred -fs:

END
START
test
TEST
tEST


Firefox cannot save Adobe Flash Player settings

Try to edit Flash settings here.

It should help :)


How To Create A Custom ErrorDocument Page In Ubuntu 14.04?

Finally I searched and tried myself and got my code working. I found that I am not activating .htaccess files in my Apache2 service. I did the following steps and got it working.

Step 1:) First Open /etc/apache2/sites-available/000-default.conf File To Edit.

Step 2:) Add The Below Codes Just Before </VirtualHost> And Save This File.

AccessFileName .htaccess (.htaccess is the default filename)
<Directory /var/www/>
 Options Indexes FollowSymLinks Includes
 AllowOverride All
 Order allow,deny
 Allow from all
</Directory>

Step 3:) Now Restart The Apache Service Using Following Command In Terminal.

service apache2 restart

Step 4:) Its Done. Now Open Any File That Doesn't Exists And You Will Get Your Custom Designed Error File.

Note: Use the same .htaccess file as I added in my question.


You may want to try this, for your second question, it's got instructions on how to do it without a windows recovery disk... and how to do it with, and a whole lot more information as well.
https://sites.google.com/site/easylinuxtipsproject/grub

Is the deleted partition now unallocated space?  There is a scenario I can think of that would cause this, if the partition you deleted is not side by side with the partition you want to expand.  If this is the case I'm not sure how to go about doing exactly what you want...  you can turn it into a logical drive, you can probably wipe some partitions between the space and the partition you want to expand (if their not hidden.)  There are probably other maybe better options I'll keep an eye open.

UPDATE: Okay found it here http://www.disk-partition.com/resource/add-unallocated-space-to-system-partition-windows7.html you have to move the unallocated space.  Beware I have not tried this application and do not know how it works, I'm just guiding you to the page.


What's the most efficient way to connect two Ubuntu 12.04LTS machines hard-drives

over the network :

You can use file sharing software like NitroShare

or else you can use default public sharing:

http://www.howtogeek.com/116309/use-ubuntus-public-folder-to-easily-share-files-between-computers/

or else Ultracopier is software you can use to copy locally from drive to drive


How to make it wokr dvb-t usb a867 on kernel 3.13.3

I have the same card and I had the same problem. Furtunatelly I was successful to update old original driver from AverMedia
You can download the patch from here. Yeasterday I found small problem in Makefile the corret line is ifneq (,$(wildcard $(KSRC)/drivers/media/dvb/.)) not ifeq (...

Extract the original driver and you copy the patch file inside the folder.
Apply the patch patch -p1 -i a867_v1.0.29.patch
Repair the line ifneq (,$(wildcard $(KSRC)/drivers/media/dvb/.)) in Makefile
Before you can successfully compile you must install kernel-headers and kernel-source
sudo apt-get install linux-source
sudo apt-get install linux-headers-`uname -r`
cd /usr/src
tar -xjvf linux-source-XYZ

The driver expect symbolic link /lib/modules/`uname -r`/source
ln -s /usr/src/linux-source-XYZ /lib/modules/`uname -r`/source

I think maybe the source file would not be necessary If you will modify the $(KSRC) variable in makefile pointing to headers. I did not tested this.
Than you should compile
make
make install
If everything will go right, you will get a867.ko module driver which will be copied into the /lib/modules/`uname -r`/kernel/drivers/media/usb/dvb-usb folder

I wrote simillar manual here (in Czech) how to get this card working. If I will find some other problems I will update the information there.
I wish you and all others good luck with this card. I hope this information will be helpful.


Ubuntu Landscape - LDAP authentification

LDAP functionality can only be enabled during the Landscape server install process and not at a later stage. Below are instructions on how to complete that with current latest Ubuntu LTS 16.04 and landscape server version 17.03.

Lets tart by Installing Pluggable Authentication Module for LDAP.

sudo apt install libpam-ldap

We need to modify /etc/ldap.conf accordingly to your needs/setup/requirements.

vim /etc/ldap.conf

and add following config, changing whats needed

base OU=XX,DC=XX,DC=XX
uri ldap://ip.of.ldap.server
ldap_version 3
# we need an authenticated user to search the directory
binddn CN=<your user>,OU=XX,DC=XX,DC=XX
bindpw <above password>
scope one
pam_filter objectclass=person
pam_login_attribute userPrincipalName
pam_password ad
ssl off

In order to activate the pam plugin, create /etc/pam.d/landscape file with below lines:

vim /etc/pam.d/landscape

and paste

#%PAM-1.0
auth    required pam_ldap.so
account required pam_ldap.so

Navigate over to the root URL for your Landscape installation and create your administrator. You will notice that an Identity field will appear. This will match the pam_login_attribute specified in your ldap.conf.


You can install extension in LibreOffice. To install,

sudo apt-get install libreoffice-pdfimport


git-flow is a git extension, not a separate command. Adds hooks to normal git. Try

git flow init

You can list files from the package with dpkg -L git-flow.

If git-flow is not installed you'll get

$ git flow init
git: 'flow' is not a git command. See 'git --help'.

The most similar commands are
        reflog
        show

Check also git-flow oh-my-zsh plugin.


Clementine, path to playlists' information

I believe that this information is stored in an sqlite database found here:

~/.config/Clementine/clementine.db

References:

Clementine: Frequently asked questions


Installation details for specific package versions on Ubuntu can be found here.

As for the breaking Wordpress 4 I can't find any know bugs right away. However if you are really nervous then do the upgrade in a test environment first.


What happens when we cancel apt-get install manually or due to network failure

how does apt-get work ?

apt-get is the command-line tool for handling packages, and may be
   considered the user's "back-end" to other tools using the APT library.
   Several "front-end" interfaces exist, such as aptitude, synaptic
   and wajig.

  what happens to data downloaded if there is network error or users cancels installation ?

If a network error or user cancels the package installation, the operation will be canceled and the partially downloaded packages are stored inside /var/cache/apt/archives directory.

  do I need to clean previous incomplete downloads before trying to install again ?

No, it's not compulsory to clean the previous incomplete downloads.

  how do I resume installation again ?

Add -f parameter or flag after apt-get like sudo apt-get install -f <package-name>. It will resumes the installation.

  how do I start a clean installation ?

Try these commands, it will remove all unused packages and will erase the downloaded archive files.

sudo apt-get autoremove
sudo apt-get clean

Now start a fresh installation of packages.

sudo apt-get install <package-name>


problem with PDF file and Document Viewer

Option 1

Open Ubuntu Software Center and search for PDF reader. There are quite a number of them you can try them one at a time and see if any of them can read the file. If not you can uninstall them using Ubuntu Software Center.

Option 2

You can download Adobe Reader from Their official website. The page will take you to a FTP site and you have to drill down the directory structure to find the latest .deb file. As of this writing it was

ftp://ftp.adobe.com/pub/adobe/reader/unix/9.x/9.5.1/enu/AdbeRdr9.5.1-1_i386linux_enu.deb

Download the file and double click on it to open it in Ubuntu Software Center. Click on the Install button and follow instructions if needed.

Best of luck.


Volume control KDE widget - how to load?

Go to the software center
Type pulseaudio control panel in search filed and search
Install it


How do I get a Realtek Wireless USB Airlink101 AWLL5088 working?

Onieric Driver: AWLL5088 Onieric 32/64bit v3.0.2590 Driver

Driver automatically updates for each kernel.
You have to install dkms and header packages, first.

(Be sure to substitute file name below with the version you downloaded.)

sudo apt-get install dkms linux-headers-generic
tar xvf Airlink_AWLL5088_Onieric_Driver-v_3.1.2590.tar.gz

cd Airlink_AWLL5088_Onieric_Driver-v_3.1.2590/

./install-with-dkms.sh

To remove from dkms use:

./remove-from-dkms.sh

The install.sh script from "Realtek" still works but wont recompile automatically for each new kernel.

http://alienlinux.weebly.com/


conjure-up openstack launch instance no console & ssh

LXD containers don't have console devices.  List container names:

lxc list

Then connect to one:

lxc exec <container_name> bash


STEPS:

First of all you have to set up you partitions, I recommend using minitool partition manager (link: http://filehippo.com/download_minitool_partition_wizard_home_edition/),
making the partitions. Make an ext-4 partition (say 100gb), this is where all your files will go, and make a linux-swap partition(say 4gb)(optional) the computer will use this as virtual memory in other words it acts as ram.
Next download rufus usb creator (link: https://rufus.akeo.ie/) and select "bootable disk using: iso image" and provide the route to it, select your image (the ubuntu iso file), select your drive (the usb stick) press ok and wait until the process is completed.

4.One all is done (you have successfully created the partitions and the bootable usb stick is ready) shutoff the computer. Press the power button and immediately press the esc key repeatedly until a menu pops up (this may vary depending on your machine). Select boot options and then another menu showing all drives should pop up. Select your usb stick and then the grub menu should pop up. choose install (ensure that secure boot and fast boot are disabled).

5.One the installation interface loads the first few steps should be simple enough for you. When you reach the section that asks you to choose the installation option (where it says "install alongside windows"... etc) choose "something else" at the bottom. Here double click on the ext-4 partition, select the format checkbox and set mount point as "/" which means root, then hit ok.

6.From here on the rest of the installation process should be simple enough for the noobiest of users. Good Luck!!


How to enable Lubuntu lightdm dinamic autologin (sorry for my english)

I found the solution. Typing rm -rf .*authority in my home folder worked.


Just install " VLC player " From " Ubuntu Software Center "
then right click on the .rmvb file > open with > " VLC player "


MySql 5.6 crashing on Ubuntu 15.04 arm64

This is likely LP: #1427406. A fix is available for 15.04 in the vivid-updates pocket, which is enabled by default on Ubuntu systems. Please try 'sudo apt-get update; sudo apt-get upgrade'.


SSH server display Motd instead of the Banner set in /etc/ssh/sshd_config

The files you need to edit live in /etc/update-motd.d.
See the update-motd man page for details about how it works.


Showing the upper and lower menu panes in Virtual box windows guest

User interface settings can be made for any virtual machine from the Virtualbox Manager in the Settings > User Interface dialog after selecting a virtual machine:

Just tick the affected bars if unticked.


Port closed for localhost but open for the remote connections

You might try something like netstat -ln | grep 143 and pay attention to the IP it's listening on.

If it's listening on 0.0.0.0, there must be some packet filtering interfering.

But if it's a specific IP like 1.2.3.4, you know that's different from 127.0.0.1 (localhost), and that's why your server is not answering.

If you are using IPv6, the corresponging situation may apply.


Is it possible (and safe) to simply delete the encrypted home directory and create a new one?

Easiest would be to delete the user including it's home folder and make a new one.
As guntbert pointed out you need to pay attention that there is always at least one account which can use sudo. So you may need to create a new account first before deleting the old one.

To get rid of the encryption only I would try looking at /home/.ecryptfs, that's where the encrypted home is (see: https://help.ubuntu.com/community/EncryptedHome).
Moving /home/.ecryptfs/$USER/ to some other place (to make the change reversible) might work (can't try right now, don't have an encrypted home).

But that won't change the passphrase of your user, you would still need to do that.


The indicator applet from Unity has been ported to gnome, it is smaller than the default one, I use it in gnome 3's fallback mode to get around the issue with the size of the bar. Try running:

sudo add-apt-repository ppa:jconti/gnome3

sudo apt-get update

sudo apt-get install indicator-applet indicator-applet-complete indicator-applet-session`

There are some screen shots and things here.

You can then add this from the 'add to panel' menu.


Upgrading from lubuntu 18.04 to 18.10 on a encrypted LUKS partition

tl;dr For me, apparently cryptsetup went missing during the upgrade. So make sure it's installed, then, do sudo update-initramfs -u -k all to ensure that you don't end up with a system you cannot boot.

I had this kind of problem the rumors are about ;) Rebooting an old kernel worked first, but after the next update-initramfs, booting any kernel would fail:

WARNING: Failed to connect to lvmetad. Falling back to device scanning.
Volume group "xubuntu-vg" not found.
Dave up waiting for suspend/resume device

I fixed this by chrooting into the broken system, installing cryptsetup, which apparently went missing during the upgrade (!!), and then properly doing update-initramfs from chroot. This is described here (unfortunately german, and when you follow it, make sure boot is mounted), but hopefully, it's not necessary when you fix the system before rebooting.


How to properly install a GNOME 3.36+ extension via CLI?

Well, It has went right after sometime!

First, as mentioned by pomsky, some of the extensions were not available for Focal Fossa's GNOME 3.36.2 yet. It was the case of ShellTille and Hot-Corn-Dog, although the second one is also reaching an error when we try to install it via GNOME extensions index GUI alternative

And, answering heynemma, even after have restarted GNOME Shell I haven't found all extensions properly installed first, however they were now!

I couldn't track what was the real problem. I have run the extensions automated installation right after had finished 20.04 system installation, so maybe something disturb it. But now, after uninstall all them and tried again, It run accordingly.

Thanks for the help anyway!
Is very useful to be able to count with the help-guided well-intentioned community of Stack Overflow


How to update driver of an existing Ubuntu installation via live usb stick

The Problem was a faulty entry in the apt-get list. So I fixed this with nano in the recovery mode. Next was to enable the ethernet device, start the networt manager, and reinstall the keyboard input drivers with sudo apt-get install --reinstall xserver-xorg-input-all
After a reboot, keyboard and mouse work well finally.


How do I stop Gimp from autolaunching on startup?

In settings Manager-> Sessions and startup ,  try to activate "remember last session", then close Gimp and the session.
At next login, it should be ok, so you can unselect "remember last session".

If still getting problems, look here  :
How can I stop the Ubuntu Software Center from autostarting in Xubuntu?


Time for an update!
I had a look around the web for useful tools that would help protect data on my machine, and have been using Timeshift successfully for some time. I'm afraid life has got in the way of finding anything else to try. At least it provides a measure of comfort-false or otherwise! Not quite the same as the tools that the system that I escaped from offers but hey... better to be free!
Thanks for the help.
Cheers.


On-screen keyboard popping up whenever I touch screen

Caribou also kept popping up to my great annoyance, so I wrote a gnome extension that monkey patches gnome-shell to stop popping up the keyboard when the touchscreen is pressed.. It's only a couple of lines of js, but the git repo is here

How to use extensions

To manage gnome extensions, download gnome-tweak-tool with

sudo apt install gnome-tweak-tool

Gnome extensions are downloaded through the official gnome-extensions website, which requires a native connector to communicate with gnome-shell. Install this native connector (even if you're running Firefox) with

sudo apt install chrome-gnome-shell

Finally to install the extension, go to the extension's page and hit the switch in the top right corner. Gnome will than prompt you to install the extension. These extensions can be managed through the gnome tweak tool. However, to uninstall them, you must use the web page.


Is there a way to make Libre Office more responsive in order to be able to center text while the window is in half-screen display

The toolbar requires a minimum screen width. If you want all buttons to remain in view, make sure you make your windows wide enough, or work with a maximized window.

Alternatively, you can customize the toolbars or change their location. You can edit toolbars and remove items, or move them to new toolbars. You can customize toolbars and other interface elements under Tools - Customize. You can also right-click the toolbar handle to access settings for changing it.

The answers to this question indicates how it can be done for prior versions of Libreoffice. For recent versions, that dialog has changed. Select the toolbar you want to customize from the dropdown menu under Target. Click the cog symbol under Target to add new toolbars.

Alternatively, grab the handle of the toolbar and drag it. You can place a toolbar vertically along the left or right side of the window by dragging it.

Thus, Libreoffice allows the flexibility to rearrange the interface in a way that works best for you.


Both 'minbar' and 'monajat' programs dont show up in the Unity Top Bar for Ubuntu 14.04, please help

I found out how to fix this, and wanted to post it here for others. I dont know how to do this in Ubuntu12.04 BUTTTTTTTTT for Ubuntu 14.04 I figured it out! Works perfectly:

★★★WHITELIST INDICATOR FIX (If Icons are Dissapearing!!!)★★★

If your favorite apps like minbar, pidgin, skype, and monojat dont have minimized icons at the TOP systray bar... Then do this! It works!!

  sudo apt-add-repository ppa:gurqn/systray-trusty sudo apt-get update ;
  sudo apt-get upgrade sudo reboot

●○◎FYI: This is 'upgrade' this it will upgrade other things in system like Firefox●○◎

Otherwise, Thats it!


The Windows Subsystem for Linux Version 1 does not have its own kernel so it's still dependent on Windows for memory usage, disk usage, ... whereas having an Ubuntu running on a native Linux kernel, there is no issue with deleting open files!  if you sudo rm --force somefile
the file will be deleted! :-)
Ubuntu running under WSL V1 still uses the Windows kernel with a translation layer in-between Ubuntu and Windows so you need to close all the applications / users that access the file as otherwise you get errors that actually don't mean anything like:

rm: cannot remove : No such file or directory

(which solved your issue)  0:-)
In Ubuntu running under WSL V2, it depends:

If running an application on a Linux file system like EXT4: no issues
If running applications in the Windows File system (aka NTFS): Windows errors still apply

Relevant XKCD:


The service management system has changed.

Every system management toolset has own utilities.  The utilities that you are used to using are the ones that come with upstart, which are trivial shims for initctl start and initctl stop.  But this is Ubuntu version 15.  You aren't using upstart any more.

You're using systemd, and the service control commands are subcommands of systemctl rather than of initctl.  So services are started with systemctl start, stopped with systemctl stop, enabled with systemctl enable, disabled with systemctl disable, and queried with systemctl status.

Services and service configuration have changed.

You've presumably followed instructions like the Serial Console How-To to turn the supplied /etc/init/tty1.conf into an /etc/init/ttyS0.conf.  This is an upstart configuration file and it will simply be ignored by systemd.  None of what you have learned from there applies to systemd, not even the concept of run levels, which is "obsolete" in the systemd world.

The systemd configuration file for a getty on a real terminal device is /lib/systemd/system/serial-getty@.service.  This is a template unit, parameterized on the name of the serial device file.  So the actual service name to use will be serial-getty@ttyS0.service.  You just enable/disable/start/stop it like any other service.

If you want an actual serial console, rather than just an ordinary serial terminal, then you don't even do that.  systemd has a mechanism that automatically instantiates serial-getty@.service whenever the kernel is told to not have its console on a virtual terminal.

Further reading

Lennart Poettering (2013-10-07).  systemctl. systemd manual pages.  freedesktop.org.
James Hunt and Clint Byrum (2014).  "Utilities".  Upstart Cookbook.
Steve Langasek (2015-04-10). Serial Console How-To.  Ubuntu.
Lennart Poettering (2013-10-07).  systemd-getty-generator. systemd manual pages.  freedesktop.org.


Multi-booting Arch Linux on an existing Ubuntu 20.10/Win7 dual boot- How do I go about it?

You shouldn't have problem installing since you're familiar with the installation process. But I find your EFI partition size might lock you down. The larger the size of the EFI the better to perform multi boot installation. As far as I understand, you're at the bare minimum. You should read about EFI partition size before doing anything further.


Does installing to an extended partition reduce disk performance?

I think that rather than the logical structure, which should not have any impact on performance, you might be observing a difference in speed due to physical locations of the partitions on the drive. The first partition might be faster than the last one.

The key to a fast boot process is low access speed (rather than transfer rates); this is why SSD will allow you to boot in seconds rather than minutes.

However, the access speeds in a hard drive can vary depending on the physical location that the reading heads need to access; the access speeds may vary as much as twofold. The main reason behind that is that as rotation speed is constant for the whole disk, more area passes under the heads on the rim rather than the area near the center of the plate. Some more information about that here.

Another thing that might influence the access speed is the partition size: the smaller the partition, the higher the speed. Here you will find the results of a test that shows how the performance can drop depending on how large a partition is.


Rebooting will work or you can run at a terminal

source /etc/environment


Live CD works, installed doesn't -- wrong display resolution

creating a xorg.conf in /etc/ is the way to go. I have a suspicion it might have something to do with autodetecting the monitor resolution.

I had a similar issue and I ran xorg -configure and generated a xorg.conf and placed it in the /etc/directory and it just worked fine.


`wget` does not download all files for svn repository

If you want all of the files (and folders?) in that subversion repository, why not use a subversion client?
sudo apt install subversion

Then:
svn checkout https://svn.sdss.org/public/data/eboss/DR16cosmo/tags/v1_0_0/likelihoods/

This should give you everything in that directory and subdirectories.


Why am I seeing only 8 colors in terminal (Xterm)?

Take a look at this answer: https://askubuntu.com/questions/147462#153493
You should modify your /.bashrc and add colors description there.

# Format: set color escape sequence \e]P, color number in hex, RGB color in hex
if [ "$TERM" = "linux" ]; then
    echo -en "\e]P02e3436" #black
    echo -en "\e]P1cc0000" #darkred
    echo -en "\e]P24e9a06" #darkgreen
    echo -en "\e]P3c4a000" #brown
    echo -en "\e]P43465a4" #darkblue
    echo -en "\e]P575507b" #darkmagenta
    echo -en "\e]P606989a" #darkcyan
    echo -en "\e]P7d3d7cf" #lightgrey
    echo -en "\e]P8555753" #darkgrey
    echo -en "\e]P9ef2929" #red
    echo -en "\e]PA8ae234" #green
    echo -en "\e]PBfce94f" #yellow
    echo -en "\e]PC729fcf" #blue
    echo -en "\e]PDad7fa8" #magenta
    echo -en "\e]PE34e2e2" #cyan
    echo -en "\e]PFeeeeec" #white
    clear # Fills terminal with base color
fi

I modified the colours to comply with Ubuntu color scheme. Bear in mind that this code is intended for standard Ubuntu installation. In your case you should change condition to [ "$TERM" = "xterm" ], as you use Xubuntu.


I had the same problem with Ubuntu 16.04 (not 18.04). I solved from Carol Yuu's suggestion in Nvidia forum.
Please try below command and install again:
sudo add-apt-repository universe
sudo apt-get update
sudo apt-get install libhdf5-serial-dev

OS: Ubuntu 16.04
HW: Nvidia Jetson TX2


"Package dependencies cannot be resolved" when installing OpenJDK Runtime

To be on the safe side go back into USC and remove OpenJDK Java 7.  or Clean up open JDK:

sudo apt-get purge openjdk*

To install OpenJDK Java 7 Just press Ctrl+Alt+T on your keyboard to open Terminal. When it opens, run the command below.

sudo apt-get install openjdk-7-jre


The command is getting truncated because % has a special meaning in cron. From man 5 crontab:

   The ``sixth'' field (the rest of the line) specifies the command to  be
   run.   The  entire  command  portion  of the line, up to a newline or %
   character, will be executed by /bin/sh or by the shell specified in the
   SHELL  variable of the crontab file.  Percent-signs (%) in the command,
   unless escaped with backslash (\), will be changed into newline charac‐
   ters,  and  all  data  after the first % will be sent to the command as
   standard input. There is no way to split a  single  command  line  onto
   multiple lines, like the shell's trailing "\".

which explains why the logged command looks something like:

CMD (find /home/steeldriver/forums/tests -type f -mtime +1 -printf ')

To demonstrate that escaping works, given:

$ ls -l tests
total 12
-rw-rw-r-- 1 steeldriver steeldriver  0 Jan 22 14:22 A8eVAmK.txt
-rw-rw-r-- 1 steeldriver steeldriver 22 Oct 27 22:18 A9E27.txt
-rw-rw-r-- 1 steeldriver steeldriver 10 Oct 27 22:19 ffn2eG6.txt
-rw-rw-r-- 1 steeldriver steeldriver 43 Jan 22 14:22 sBHFgkv.txt

Then adding the crontab as:

* * * * * find /home/steeldriver/forums/tests -type f -mtime +1 -printf '\%P\0' | rsync -0av --exclude-from=- /home/steeldriver/forums/tests/ /home/steeldriver/forums/newtests/ 2>&1 > /home/steeldriver/forums/backup.log

(note this uses the null-terminated form \0) produces the log file:

$ cat backup.log
sending incremental file list
created directory /home/steeldriver/forums/newtests
./
A8eVAmK.txt
sBHFgkv.txt

sent 250 bytes  received 113 bytes  726.00 bytes/sec
total size is 43  speedup is 0.12

indicating that the backup ran successfully and copied only the newer files:

$ ls -l newtests
total 4
-rw-rw-r-- 1 steeldriver steeldriver  0 Jan 22 14:22 A8eVAmK.txt
-rw-rw-r-- 1 steeldriver steeldriver 43 Jan 22 14:22 sBHFgkv.txt

Note that you won't be able to test the escaping outside of your crontab - in the terminal, it will result in an error from find.


How to install Ubuntu 13.10 on Hybrid Disk alongside Windows 8.1

You have a BIOS install, not UEFI. And your main hard drive has all 4 primary partitions used.
You need to run the dmraid commands on both drives and make sure you have turned off hibernation and Intel SRT caching in Windows. Not sure with Windows 7 if it is like 8 or not.

sudo dmraid -E -r /dev/sda
sudo dmraid -E -r /dev/sdb

My disk already has 4 primary partitions, how can I install Ubuntu?

How do I install Ubuntu?

Was system UEFI booting before? That would leave gpt data on drive also that causes issues. Otherwise just be sure to boot in BIOS mode even if system is UEFI capable.


Run this command to edit ports.conf file
sudo gedit /etc/apache2/ports.conf

Add below line in the begining of the file.

Listen 0.0.0.0:80

And make sure that /etc/apache2/sites-enabled/000-default.conf files first line is equal to below line

<VirtualHost *:80>

http://httpd.apache.org/docs/2.2/bind.html


Lightweight image-viewing app to slideshow images and animated gif in random order

feh has the ability to display images in a random order using the -z flag, unfortunately however it cannot display animated gifs.

It is also extremely light and fast and can handle almost any file type.


Is there a command to set a date to year 9 instead of 2021?

Linux systems cannot have their system date set to a time before the UNIX epoch, which is 1 January 1970.


What is 'Getty'? I noticed there are six occurences of it in my System Monitor

getty is what sits on the text-mode consoles and waits for someone to log in.  It configures the tty device and spawns login when typed at; historically it adapted to the communications line based on what it received, but especially on VCs this is no longer necessary.


Change name of executable file when using chmod +x

There is only 1 file, my_script.py. Doing a simple chmod +x does NOT "end up with two files called my_script.py" (what would the 2nd my_script.py be called?).

Since Python is an interpreted language, you might want to consider the size of the python interpreter, and both the dynamic libraries and interpreted libraries it uses.

When the execve system call (see man 2 execve) notices that my_script.py is executable (has the x bit set), and begins with "#!<interpreter>" it runs <interpreter> my_script.py (interpreter> is probably /usr/bin/python in your case).

So, you can simply mv my_script.py my_script. Unlike that other operating system, Unix/Linux filenames do NOT govern how the files are executed.


Absolutely! You will be happy to know that if you write a KDE Plasmoid, you have access to the Geolocation API in HTML5, which provides precisely the data you want without you having to worry about how it is implemented.

Getting started with Plasmoid development
Simple demo of how to use Geolocation API (source link on page)


Ubuntu Server Bionic Beaver non-graphical change resolution

Modify / add the following lines to /etc/default/grub to match the ones below

GRUB_CMDLINE_LINUX_DEFAULT="video=<your_video_mode> gfxpayload=true"
GRUB_CMDLINE_LINUX="video=<your_video_mode> gfxpayload=true"
...
# The resolution used on graphical terminal
# note that you can use only modes which your graphic card supports via VBE
# you can see them in real GRUB with the command `vbeinfo'
GRUB_GFXMODE=<resolution_needed>
GRUB_GFXPAYLOAD=<resolution_needed>
GRUB_GFXPAYLOAD_LINUX=<resolution_needed>

Run update-grub

sudo update-grub

Reboot

sudo reboot

You can find more information here.


How to configure SoundJuicer mysterious mp3 encoding settings?

Unfortunately the version of sound-juicer that you are using suffers from a bug in gstreamer which means that the xing header is not written to mp3 files. Without this header most software will report incorrect track lengths and bitrates. It is possible to use vbrfix to fix the files you have ripped. As others have pointed out there is a work around for this bug in later versions of sound-juicer.

I'm currently working on a feature to allow users to change the encoding bitrate, this should be available in sound-juicer 3.18 which will be released in September. In the mean time you can follow progress on the bug which you linked to, or if you're feeling brave try compiling the wip/encoding-presets branch (Once the UI is done that will require GTK 3.12 which means Ubuntu 14.10 or later I think or you can try using jhbuild to build the necessary dependencies)


How to Migrate Physical 12.04 Machine into LXC

Since I posted this question I have done this process half a dozen times without too much trouble. I thought I would add some hints from what I've learned in the hope that someone finds them useful:

All you need to do is copy the root file system into the container's rootfs directory (/var/lib/lxc/YOUR_CONTAINER/rootfs/ for disk based backing storage). Exclude /proc, /dev, /sys and /tmp.

Afterwards:

Make fstab empty in the container
Ensure a minimal set of device files under /dev. I copy the device files from a sample container that I created using a template.
If you are going to use lxcbr0 for networking, set the network interface to DHCP in /etc/network/interfaces
If you are going to bridge to a physical interface, set the interface to
static or manual. If manual, put the IP address in the container's config. Do not set to DHCP.
be sure you set a hwaddr in your container config. If you don't LXC will randomly generate one when the container loads causing a lot of stale ARP entries on your network.
read through /usr/share/lxc/templates/lxc-ubuntu. Pay special attention to the configure_ubuntu() function. You probably want to run most of those commands in your container.

After the container is up, go through all the processes in pstree, removing those that aren't needed in containers (udevd, ntpdate, mdadm, etc). Feel free to remove all kernel packages.

Here is a sample container configuration for completeness. This configuration is for a trusty host. The container in this instance is precise.

lxc.include = /usr/share/lxc/config/ubuntu.common.conf
lxc.start.auto=1
lxc.rootfs = /var/lib/lxc/myhost/rootfs
lxc.mount = /var/lib/lxc/myhost/fstab
lxc.utsname = myhost
lxc.arch = amd64

# Network configuration
lxc.network.type = veth
lxc.network.flags = up
lxc.network.link = br0
lxc.network.ipv4 = 172.27.3.13/24
lxc.network.ipv4 = 172.27.3.15/24
lxc.network.ipv4.gateway = 172.27.3.1
lxc.network.hwaddr = 52:12:a1:a5:d3:23

If the host OS is precise, you'll want this in your config as well. The common file won't be available.

lxc.devttydir = lxc
lxc.tty = 4
lxc.pts = 1024
lxc.cap.drop = sys_module mac_admin
lxc.pivotdir = lxc_putold


web-e's setpci command (from the comment) helps me:

setpci -s 00:02.0 F4.B=00

Now the backlight changes.


Unable to do ./configure during emacs installation

Probaly You need to run

./autogen.sh

before that. Have You read README?


New computer hangs on shutdown/reboot, how to troubleshoot?

This answer on Ubuntu Forums has the exact solution! (Why didn't I post there in parallel to here on AU? It would have saved a week of calendar time and several hours of computer time!)

  The wrong driver is loaded which
  prevents shutdown. To fix it you need
  to do this:

  Open a terminal and type: sudo modprobe -rf rt2860sta

  Followed by: sudo modprobe rt2860sta

  Then you need to blacklist the wrong driver:
  echo blacklist rt2800pci | sudo tee -a /etc/modprobe.d/blacklist.conf

  Once you have rebooted (you will need
  to do a hard power off for the last
  time!) you will find you can reboot
  properly.


Find out exact time when the Ubuntu machine was rebooted

last reboot | head -2

gives the last reboot times in a format like
reboot   system boot  5.4.0-58-generic Thu Dec 31 11:43   still running
reboot   system boot  5.4.0-58-generic Wed Dec 30 20:56 - 22:27  (01:30)

or use
last reboot --time-format full | head -2 | tail -1

to get something like
reboot   system boot  5.4.0-58-generic Wed Dec 30 20:56:16 2020 - Wed Dec 30 22:27:05 2020  (01:30)

or use something like awk to extract the end date
last reboot --time-format full | head -2 | tail -1 | awk -F ' - ' '{print $2}' | awk -F '(' '{print $1}'

-->
Wed Dec 30 22:27:05 2020

https://www.cyberciti.biz/tips/linux-last-reboot-time-and-date-find-out.html


The unicode fonts layout provided by Ubuntu vs. the official font layout

There is a known issue with Nepali romanized keyboard shipped with certain version of Ubuntu. correct version here

  The Nepali Romanized Keyboard layout shipped with Ubuntu (located at
  /usr/share/X11/xkb/symbols/np) is incomplete. The definition for the
  whole upper row (1-0 keys) are missing. Also, more importantly,
  zero-width joiner (ZWJ) and zero-width non-joiner (ZWNJ) characters
  are wrongly defined

Jwalanta tackles this problem in detail in his blog

there is keyboard layout editor if you want to create a new layout yourself This has some issues in 12.04 but there are workarounds

edit:

I got tired with issues in standard layout so built these based on iBus

one similar to Preeti and other ttf fonts
transliteration based


How can I disable backlight when I lock the screen?

I am running a script for same problem (source):

#!/bin/bash
sleep 0.5
xset dpms force off
gnome-screensaver-command -l

This turns monitor off and locks the session. The sleep 0.5 is there to avoid the monitor turning on when you release the Ctrl+Alt keys; maybe you don't need this.

You can try other solution also from there (didn't tried this one yet).

The solution I use is:

I have added the Inhibit Applet to my top panel (this lets me toggle the sleep mode off and on)
In power management I set Put display to sleep when inactive for: 1 minute.
I use the Ctrl+Alt+L (I actually changed my shortcut to Ctrl+Alt+Spacebar) to lock the screen.

So when I am using the laptop the first thing I do is click on my Inhibit Applet in my top panel so my display does not go to sleep in 1 minute of inactivity.

When I am all done and want to lock the screen and turn off the monitor I click on the Inhibit Applet so it allows the sleep timer to work, and I hit my combination of keys to lock the screen Ctrl+Alt+L.

The Screen is locked and in 1 minute the display turns itself off.


I found the solution by myself.

You have two keys, one is pub and other is sub

edward@computer:~$ gpg --edit-key CEF41E5C
gpg (GnuPG) 1.4.18; Copyright (C) 2014 Free Software Foundation, Inc.
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law.

Secret key is available.

pub  4096R/CEF41E5C  created: 2015-07-27  expires: never       usage: SC
                     trust: full          validity: unknown
sub  4096R/BB84D566  created: 2015-07-27  expired: 2015-08-26  usage: E
[ unknown] (1). edward torvalds (encrypt the world) <ltorvalds024@gmail.com>

as you can see my  pub key is fine but sub key is expired
now select sub key

key 1

next

expire

then enter the time after which it should expire, I choose 0 which means never

save

Done! :-)


quantal: suddenly, notify-osd doesn't show bubbles

Try to reinstall the incriminated packages with:

sudo apt-get --reinstall install libnotify-bin notify-osd


Mate desktop weird red icons in top right corner, how to remove/fix?

I just installed Ubuntu mate 18.04 on my odroid and had similar problem, I was able to remove the icons by right clicking the 3 dots to the left and click lock, right click the 3 dots again and click remove.


ubuntustudio-controls jack and suspend//resume

Jack simply doesn't support suspend/resume as it's simply not designed for it. You need to stop Jack via ubuntustudio-controls before putting your machine into a suspend state.


Wifi not working after switching off with button after upgrade to 16.04

I have seen this error before:

  rt2800_wait_wpdma_ready: Error - WPDMA TX/RX busy

Please see: https://forums.opensuse.org/showthread.php/506888-OpenSUSE-13-1-wireless-problem-with-firmware-Ralink-RT3290-(kernel-4-0-0-1-1-g49e42b3-x86_64)

In the post I linked, it says:

  While I was waiting for answers I did recall reading someone in these
  forums suggesting to remove 802.11n from the router .

  So I tested that today it it worked.

  That is, I set the router to broadcast only 802.11g. ( Previously
  802.11n was among the protocols it broadcasted.)

  And it WORKED. wlan has been on since this morning with no glitch.

Also see: https://ubuntuforums.org/showthread.php?t=2334099

  YES!! I removed 802.11n, leaving both "b" and "g" on, and it works!!
  thank you very much!!

Please change the setting on your router to use 802.11B and G only and not N. Reboot the router and see if you connect.


Test Open vSwitch vs Linux bridge vs Open vSwitch with DPDK

Hi and thanks for the drawing, that helps a lot.

I need to clarify - is it a mistake or really just one device in Server 2 as both sides are called "eth2"? I haven't seen bridging between to e.g. vlans with DPDK as that is at a higher level.
For now I'm assuming your Server 2 has two DPDK capable network devices (actually three to have one remaining for control).

You would then on server 2 dedicate both network devices to DPDK and add them to openvswitch. See the Serverguide for some examples. There is an update pending to integrate how this is done for the OVS/DPDK versions available in Yakkety.
OVS will naturally bridge traffic between those two ports without further configuration.

Warning: make sure those two ports are not part of the same physical network. Doing so would re-reflect all traffic and self amplify itself - finally killing the whole network segment with this being a self made DOS attack.

Once you have set this up, you can run any sort of traffic from server 1 <-> server 3. Iperf is fine for simple streaming workloads. Other common simple tests are netperf and uperf. Configuring all three can be found in the test examples linked here.

For some simplified testing on Ubuntu which can be done on just one machine with two DPDK capable ports feel free to take a look at simple dpdk tests. Some day I intend to set up something similar to your drawing in that with virtual machines to then modify flow rules in between and check the impact of number and complexity of them, but had no time yet.

Finally if you want to go bigger you could consider using server 1 (if enough interfaces are available) with a DPDK based traffic generator like for example Moongen or TRex.


You're on the right track. Just make sure Evolution is closed when you edit and save the ~/.config/evolution/accels file.


A keyring is a "stored database" -- I'm using this term lightly -- of your login information stored on your local PC. It's wrapped by some magic voodoo encryption schema (PKCS#11 - this is used for secure storage on removable media) so it's going to be relatively secure from prying eyes.

It provides a common backend for (insert framework here, we will use gnome for an example) to CRUD (create, read, update, delete) your login information without "rolling your own solution". It keeps a consistent interface for programmers utilizing that particular framework. KDE provides its own keyring, Gnome has another implementation of it.

Evolution, Firefox, Net-man all utilize this interface. When you place your email server credentials into Evolution it asks you to store that information in the keyring. If you opt into it, it passes the data off to the keyring service and voilà, it's stored. Evolution only has to subsequently call the keyring service on startup to retrieve that information.

The big idea here is that if someone else were to access your PC and did not know the master password to your keyring, they could not access your stored login information. The same principle is put to use by lastpass.com's addon for your browser. (only it's distributed, meaning I can use it on several instances of browsers across PC's)

In summary, I offer this snippet from the gnome-keyring page located here

  GNOME Keyring is a collection of components in GNOME that store
  secrets, passwords, keys, certificates and make them available to
  applications.

  GNOME Keyring is integrated with the user's login, so that their
  secret storage can be unlocked when the user logins into their
  session.

  GNOME Keyring is based around a standard called PKCS#11, which is a
  standard way for applications to manage certificates and keys on smart
  cards or secure storage.


Was Ubuntu the first software project to adopt a code of conduct?

I wrote the first draft of the Ubuntu Code of Conduct on my first full day of work at the company that would later become Canonical while sitting on a couch on Mark Shuttleworth's flat in London.

I can't say for certain that no other free software/open source project had a Code of Conduct before but I can tell you that I didn't know of any other free software projects that did at the time and haven't learned of any since.

I don't remember looking carefully at any other similar documents from other communities (software or not) when we drafted Ubuntu's. In drafting the Ubuntu Code of Conduct, we relied heavily on our experience in Debian (and other free software projects) to identify types of behavior that we loved and wanted to encourage as well as behavior that we wanted to clearly state wouldn't be welcome in the community we were planning to build.


Ubuntu 13.10: Broadcom 43142 not finding bluetooth devices

I am using the driver wl driver from Broadcom at http://www.broadcom.com/support/802.11/linux_sta.php The driver needs to be patched and I got the patch file from one of the arch linux forums. Make and installed wl.ko and remember to load the btusb module for bluetooth to work


Wifi usb not working Ubuntu server/desktop 20.04.1 TP-link archer t4u ac1200

Please unplug the device. Next, with a working internet connection by ethernet, tethering or whatever means possible, open a terminal and do:
sudo apt update
sudo apt install wireless-tools wpasupplicant

In our chat, we determined that you have a driver rtl8812au loaded on your system and that it was, upon examining dmesg, throwing numerous errors. We blacklisted it.
I recommended that you try another, more current version:
wget https://github.com/aircrack-ng/rtl8812au/archive/v5.6.4.2.zip
unzip v5.6.4.2.zip
cd rtl8812au-5.6.4.2/
sudo make dkms_install

Reboot
After the reboot, the wireless was working. Next, please configure netplan as outlined in the example:
cat /usr/share/doc/netplan/examples/wireless.yaml


Where can I find current laptop temperature?

I am able to find the temperature for my Toshiba laptop, expressed in 1/1000 of a degree Celsius, in _/sys/class/thermal/thermal_zone0/temp_

cat /sys/class/thermal/thermal_zone0/temp
51000

and acpi -t returns:
Thermal 0: ok, 51.0 degrees C

My system only has a thermal_zone 0 but I suppose other systems may have more than one zone.


13.04 doesnt remember wired network password

I had this same problem after my upgrade to 13.04, I was able to solve it by following the directions on this response in a thread asking about the same thing, but occurring in 11.10.  Good luck!


FAT32 and NTFS are both file systems. Each file system has its own way for storing and retrieving data.

Windows can use FAT (FAT*), exFAT and NTFS, where NTFS is the default.

Linux can use ext (ext*), ZFS, ReiserFS, btrfs and a lot more, including every file system Windows can use, where ext* is the default (usually ext3 or ext4).

So, if you want to be able to share data between Windows and Linux, you should choose a file system both operating systems can use. I suggest NTFS, as FAT and exFAT have their limits.

However, you cannot install Linux on a NTFS partition, so you should create a seperate system partition (ext*) to install Linux on.

You'll have to resize partitions in order to create a new partition (for Linux), because you're already using your whole disk for Windows (NTFS).

This may cause data corruption, so please make a backup of your important files before you do this, or make an image of your whole hard drive.


How to opendns on router with dynamic ip

Edit the dhcp configuration file /etc/dhcp3/dhclient.conf

And add this line:

prepend domain-name-servers 208.67.222.222, 208.67.220.220;

This will prepend the OpenDNS nameservers with dynamic IP.


Actually, this is not a driver problem. This is due to a change in the X server, which has been switched from root to rootless. This is a very common problem. Since the X server is now rootless, it doesn't have permission to access the frame buffer device. Actually, it should auto-detect, when root is needed. But often it doesn't. There are 2 settings for that. You might want to read man Xwrapper.config to learn about it. However, this usually doesn't really solve the problem. You also need to add the user(s) to the video group (sudo usermod -a -G video LOGINNAME). If you still get and error, you might need to set your environment variable DISPLAY too. This is either done by something like export DISPLAY=127.0.0.1:2.0 (temporary) or in /etc/environment (permanent).


Some fast way to save and restore tabs of Terminal?

To save configuration into /tmp/cfg:

gnome-terminal --save-config=/tmp/cfg

To load it back:

gnome-terminal --load-config=/tmp/cfg

UPDATE

After playing around with bash I created following script which stores tab names into file /tmp/test as well:

#!/usr/bin/env bash

gnome-terminal --save-config=/tmp/test

LINES=($(grep -n '\[Terminal' /tmp/test | cut -d: -f1))
for ((i=0; i<$(grep '\[Terminal' /tmp/test | wc -l); i++))
do
    TITLE=$(xprop -id $WINDOWID WM_NAME | sed -e 's/WM_NAME(STRING) = "//' -e 's/"$//';xdotool key ctrl+Page_Down;)
    sed -ri "$((${LINES[$i]}+$i))s/.*/&\nTitle=$TITLE/" /tmp/test
done

To assign names properly you have to run it from first tab of your terminal. Loading same as before:

gnome-terminal --load-config=/tmp/test

EXPLANATION:

I can use following to get tab name:

xprop -id $WINDOWID WM_NAME

I can use following to jump to next tab:

xdotool key ctrl+Page_Down;

I'm getting number of tabs after grepping configuration file I saved before:

$(grep '\[Terminal' /tmp/test | wc -l)

So I can iterate over tabs inside a loop. I have to add "Title=titlename" entry for each tab configuration section in file saved before. To do so, first I'm creating an array of line numbers where I'll be adding lines.

LINES=($(grep -n '\[Terminal' /tmp/test | cut -d: -f1))

I'm adding "Title=titlename" line inside of loop iterating over tabs:

sed -ri "$((${LINES[$i]}+$i))s/.*/&\nTitle=$TITLE/" /tmp/test


Ubuntu 16.04 running very poorly on full install on flash drive even though it ran well on Virtual Box

Running slow because of low USB throughput

When running Ubuntu from a USB-Stick and starting programs or loading data, the throughput of your USB-Stick will be a bottleneck. This is why you experience low performance although Ubuntu now has direct hardware access. The access time of your hard drive / SSD is significantly faster than USB throughput.

Install onto new partition for increased performance

To get good performance (comparable / probably faster than Virtual Box), create a new partition on your hard drive and install Ubuntu there. You will require about 5 GB of space minimum.


I don't have permission for anything! please help

/home/user/.gvfs is the mount point for a virtual filesystem used by Gnome. It cannot be accessed by any other user than the session owner (not even root) while a Gnome session is active.

By default chown only prints error messages so if you don't get any other response from chown that means everything else worked fine.

If you still can't create or delete files in your home folder please post the output of the following commands:

ls -ld ~/
touch ~/this_is_just_a_test_file
rm -v ~/this_is_just_a_test_file


How can I promote Linux or ubuntu to my clients who are not very computer savy?

You should say what I am saying to my friends(windows users): Yes because It is new to you. You addicted to a none standard OS which prefer ease of use to safety. Ubuntu is a new world. With its graphical environment you will have same thing (very easy) but still very secure and stable. The hard part of Ubuntu is its command line. It is learn able and almost same thing as any other POSIX OS like mac and uinx and it will make you very powerful. I suggest you the ultimate power, security and stability. And more important it is all FREE!!!


Try this.
sudo apt-get install <package> -y

The -y flag means yes.


14.04 LTS on HP EliteBook 8740w with NVIDIA and DreamColor

I am going to answer my own question as nobody else did. What I didn't know then and what I know now is when installing Ubuntu there are a few fundamental settings, like keyboard layout, language (I knew that). There is also an option called "nomodeset" which will install Ubuntu using a generic graphic mode and driver which is supported by probably all graphical subsystems. Choosing this will make it possible to install Ubuntu 14.04 LTS (and other versions) and once installed it is easy to get the driver for the Nvidia graphics working.


how to use Ubuntu 18.04 (netplan) with a VLan

The sample code I included in my question had become a bit messy from following other tutorials.
The answer provided by @Frobozz was accurate based on the question I asked, but the actual code I needed, in the end, was this. It was because of @Frobozz response that I started to understand what I needed to google for.
network:
  version: 2
  renderer: networkd
  ethernets:
    eth0:
      dhcp4: no
      dhcp6: no
  bridges:
    br10:
      dhcp4: no
      dhcp6: no
      interfaces: [ vlan10 ]
      addresses: [ 192.168.10.20/24 ]
      gateway4: 192.168.10.1
      nameservers:
        addresses:
          - "192.168.10.3"
          - "8.8.8.8"
  vlans:
    vlan10:
      id: 10
      link: eth0
      dhcp4: no
      dhcp6: no


Sound Setting interface changed after reinstall alsa-base and pulseaudio

It's gnome-control-center that got installed instead of unity-control-center.

sudo apt install unity-control-center
sudo apt purge gnome-control-center


See this bug.

Run this command to kill Nautilus (Files):

killall nautilus


Ati cards need mesa 7.11. Where can i find it

In the mean time there is ubuntu 11.10 with mesa 7.11.  Now i have a wine application working. The radeon drive is still not working as he is working in Windows, but i think there is hope.


ubuntu 12.04 - postfix - postmap missing

postmap is included in the postfix package.

As you can see on Ubuntu Packages it's located in /usr/sbin/postmap.

If you can't run it you can try the following:

Run /usr/sbin/postmap directly

If it's not there, try to reinstall postfix

sudo apt-get --reinstall postfix

Check if /usr/sbin is in your PATH (/usr/sbin will be highlighted using grep)

echo $PATH | grep /usr/sbin

If it's not there, add it

nano ~/.bashrc

and add the following line (also run this in your terminal to apply this fix without a restart)

export PATH=$PATH:/usr/sbin


Auto Indentation not working in Code-blocks 13.12 (svn 9636)

Install contrib plugin by:

sudo apt-get install codeblocks-contrib


Grails `run-app` fails when port is set to 80?

As João Pinto notes, ordinarily only root can bind to privileged ports (1-1023). It's probably more common in cases like this to set up some kind of reverse proxy server (apache, nginx, lighttpd, etc.) to listen on port 80 and send requests back to the grails app running on a higher port.


Setting up multiple network interfaces with netplan for a LAN and a direct connection

What do you mean by "connect from outside my LAN"?

You can not access 192.168.x.x or 10.x.x.x or any other private IPv4 from outside unless you have a gateway with a forward rule.


fglrx fails to load causing black screen on boot

You shouldn't have purged flgrx, really.

I experienced exactly same problem after updating to 11.04 (booted fine with old kernel 2.6.35, but trying to boot with default kernel of 11.04 I had blank screen and blinking cursor)
All I had to do is add radeon.modeset=0 to grub options (along with quiet splash)
once you can add this option pressing E in grub menu for permanently editing and updating grub.

If anything, you can edit grub options doing

gksudo gedit /etc/default/grub

The line will look like something ... ="radeon.modeset=0 quiet splash".

Save the grub file then update the grub config using sudo update-grub.


How to audit file created under a specific path?

You have a couple of options - there is a commercial product called Tripwire which can watch folders or files for changes, or, as per this post on ServerFault you have OSSEC.

There are others that do the same sort of thing. Have a search for Tripwire alternatives.


How to add second adapter to guest OS in VirtualBox?

With VMWorkstation, I needed to:

Add the virtual adapter(s) via the main VM Network Editor, with DHCP enabled.
Remove and reinstall Ubuntu Server for it to recognize the additional adapter(s)
The DHCP configuration is saved in the /etc/network/interfaces configuration file, but the file is read only.   Modify attributes on file to make it read write.  (chmod 666 <filename>)
The edit the etc/network/interfaces file to add the additional interface(s) to use DHCP:

auto eth1
iface eth1 inet dhcp

Issue the sudo service networking restart command to re-enable the network interfaces.


As at 8/3/2020 follow the instructions Here. They come in two parts, make sure you also follow the ones for your platform. They are a bit jumbled on the site so I have included them below.

I'm running 18.04 LTS (Bionic) on a 2013 Macbook Pro. The instructions that worked for me were as follows:

sudo apt-get install git
sudo apt-get install curl xzcat cpio
git clone https://github.com/patjak/facetimehd-firmware.git
cd facetimehd-firmware
make
sudo make install
cd ..
sudo apt-get install kmod libssl-dev checkinstall
git clone https://github.com/patjak/bcwc_pcie.git
cd bcwc_pcie
make
sudo make install
sudo depmod
sudo modprobe -r bdc_pci
sudo modprobe facetimehd
sudo nano /etc/modules
**add line "facetimehd", write out (ctl+o) & close**

Most of those steps will need to be repeated every time the kernel is upgraded.

I also followed the instructions here prior to testing the colors of the camera.


Try mounting the drive manually.

get the device name either from dmesg or 'fdisk -l'
'sudo mount /dev/sdb1 /home/user/usbdrive'

/dev/sdb1 could be something else.


Getting error run sudo apt-get upgrade on ubuntu 16.04

You have to trick over this problem. Remove the problematic file-list, reinstall the package by:
sudo rm /var/lib/dpkg/info/policykit-desktop-privileges.list

sudo apt-get update
sudo apt-get install --reinstall policykit-desktop-privileges

then fix three other mentioned packages by
sudo apt-get install --reinstall libqt5webkit5:amd64
sudo apt-get install --reinstall libsamplerate0:amd64
sudo apt-get install --reinstall libsane-hpaio:amd64

then install all upgrades for current release
sudo apt-get upgrade # upgrade packages
sudo apt-get dist-upgrade # upgrade packages with all new dependencies

and then consider upgrading to 18.04 LTS as was recommended in comments.


Lost wireless connectivity after suspend on Lenovo Z5070

If you previously installed a driver form source using this guide, you will need to re-install it after each kernel upgrade. That may be the case.

If you did not remove sources, then run

cd rtlwifi_new
make
sudo make install

If you DID remove the sources, then download driver as zip.

Extract it to your home folder and install by

cd rtlwifi_new-master
make
sudo make install

And reboot

Also after sleep mode sometimes Network Manager is stuck. You can restart it using

sudo service network-manager restart


Your issue is caused by fast start up which causes windows to always put the system into a suspend to disk state so when the computer turns back on it loads out of ram skipping any OS selections. While you can technically get around this by cutting power to the computer (so the bios loads again) or by using the restart option instead of the shutdown option in windows its generally recommended you disable fast start up on dual boot systems. Windows file system will be left in a hibernated state which Linux NTFS driver doesn't handle.

You can disable fast start up in the Windows control panel by going to Power Options, "Choose what the power buttons do", "Change settings that are currently unavailable", Uncheck "Turn on fast startup" and save changes.

You should then be able to restart or shutdown and repower and have an OS selector.


Gnome Terminal not showing up in unity, Why?

On your launcher, on the left side of the screen, at the bottom should be this button:

Whenever you click it, it should sprawl out all of your workspaces, and you can see what windows are open.

Alternatively, you can use Super+S to open up all of your workspaces as well.


On some systems the embedded controller that performs the battery level handling can get stuck.  In these cases I've resolved the issue by removing all power from the laptop and removed the battery for a few minutes to ensure that the embedded controller has powered off.  Placing the battery back in the laptop has resolved the issue.


I have been interacting with my colleagues regarding this Wireless hotspot thing. People are saying that 12.10 has really screwed it up. This was working in 12.04.


laptop not booting to 20.04 usb made with rufus

TUF A15 FX506IV user here. I had the same issue with installing windows, as I removed the original M.2 drive and replaced it with a blank drive.
I tried a long time to get it to boot, then went and made myself some food. When I came back, it had somehow magically discovered the USB stick and started windows install.
I have since been unable to boot from USB again.
Something is funky with USB boot on FX506. Replacing rufus with balena makes no difference. The BIOS sees the USB stick, but refuses to show it as a boot option. Disabling secure boot and fast boot does no difference. Additionally there's no CSM option in the BIOS.


Undefined reference to symbol acos@@GLIBC_2.2.5 while compiling xpdf

After debugging the code, the solution I used was to add -lpaper to the DCMAKE_CXX_FLAGS or the DCMAKE_EXE_LINKER_FLAGS during the cmake command, either works. Thanks @steeldriver for very good insights.


Ubuntu and Windows 8.1 dual boot problem

Im no expert as i am only young but have you checked that your bios is set to boot ubuntu as default if not check it by pressing the del key when you see the asus logo and go across to boot in the bios options from here you should be able to view the priorities and enable or disable them, check windows is enabled then make it priority.


As far as I know, %-4.4h and %2.1d are not valid format specifiers for the GNU date command - in particular, precision modifiers don't make sense and are not supported. The accepted modifiers are:

   After any flags comes an optional field width, as a decimal  number;  then  an  optional
   modifier,  which is either E to use the locale's alternate representations if available,
   or O to use the locale's alternate numeric symbols if available.

("decimal" here just means digits 0-9).
The format specifiers for full month name and day of month are %B and %d respectively (you can use lowercase %b or %h for abbreviated month name ex. Sep for September). So for example:
$ date +'%B %d %H:%M'
May 12 07:46

$ date +'%B %d %H:%M' -d 'today + 4 months'
September 12 07:48

$ date +'%b %d %H:%M' -d 'today + 4 months'
Sep 12 07:50

Note that field width specifiers are minimum widths, so for example
$ date +'%4B %4d %H:%M'
 May 0012 08:04

pads May to 4 characters, but
$ date +'%4B %4d %H:%M' -d 'today + 4 months'
September 0012 08:03

does not truncate September to Sept.
See man date for a full list of % specifiers.


Could I have black bars (a.k.a. overscan) on my monitor please?

I have nvidia, so I can't say for sure that what worked for me will work for you. Differences in capability may also come down to available features offered by the actual monitor as well.

I'll address brightness and overscan separately

Brightness:

If your screen is too bright at night, try a program like redshift. It doesn't reduce backlight. It's a software-based approach to "[adjusting] the color temperature of your screen according to your surroundings." Basically, the screen is less harsh to look at when the sun goes down and there's less ambient light.

Overscan*:

xrandr is your friend here. Basically, you want to open a terminal, use xrandr to find the overscan property and then set the overscan. Here's how I did it on mine.

In a terminal, run xrandr --prop. This will spit out properties for all video output devices, connected or disconnected. Look for the the section pertaining to your connected display. Mine looks like this...

HDMI-0 connected primary 1680x1050+0+0 (normal left inverted right x axis y axis) 474mm x 296mm
CscMatrix: 65536 0 0 0 0 65536 0 0 0 0 65536 0
EDID:
    00ffffffffffff005a63248201010101
    14140103802f1e782e78f5a655489b26
    125054bfef80a940950f950081808140
    714f0101010121399030621a274068b0
    3600da281100001c000000ff00524d41
    3130323030353632390a000000fd0032
    4b185211000a202020202020000000fc
    00564132323332205365726965730031
BorderDimensions: 4
    supported: 4
Border: 0 0 0 0
    range: (0, 65535)
SignalFormat: TMDS
    supported: TMDS
ConnectorType: HDMI
ConnectorNumber: 1
_ConnectorLocation: 1
1680x1050     59.95*+
1600x1200     60.00
1440x900      74.98    59.89
1280x1024     75.02    60.02
1280x960      60.00
1152x864      75.00
1024x768      75.03    70.07    60.00
800x600       75.00    72.19    60.32    56.25
640x480       75.00    72.81    59.94

HDMI-0 is my output and Border: 0 0 0 0 is property of interest to me. Beware, properties appear to be case sensitive!
Now I run xrandr --output HDMI-0 --set Border 100,100,100,100, and it creates a 100-pixel black border all the way around my screen.
To reset, I run xrandr --output HDMI-0 --set Border 0,0,0,0, and the border is gone.

If you wanted, you could bind these to keyboard shortcuts to turn the overscan on or off.

*Warning: I noticed that when I maximize windows on my screen, the rightmost edge of the window is not visible and falls under the black border. This may be because I have dual monitors though. This is not a problem so long as I do not maximize windows and keep the window moved and resized such that it fits within the visible workspace.


How to enable lubuntu-12.10-alternate-amd64.iso to PXE network install the graphical desktop?

Once you set up the TFTP server it is really straightforward with any ?-ubuntu's 12.10: two commands on the shell.
Just bind/mount your TFTP server web root to the subfolder ./install/netboot in the Alternate ISO image of the OS.

If you have correctly setup Linux-based TFTP server, then:

Let /srv/tftp be your TFTP webroot
Let /path_to_image/Lubuntu.iso be your ?-ubuntu OS image file;

then just type in (as root):

mkdir /mnt/tmp
mount -oro,loop,iso9660 /path_to_image/Lubuntu.iso /mnt/tmp
mount --bind /mnt/tmp/install/netboot /srv/tftp

Reboot your client and it's done to receive the ?ubuntu OS via PXE.


Why is the TIME 00:00:00 for bash process in ps command

The ps command reports the CPU usage of a process in seconds. If you want to get this information in milliseconds, you can look at the end of this answer.
ps truncates the total CPU time used by the process to the nearest low second, so you can safely assume that the process you looked up (bash in your case) had used less than one CPU second so far.
This is normal, because bash does not do any number crunching stuff to spend too many CPU cycles. bash simply reads commands from input and calls the relevant executable to do the job requested by the command.
bash itself is not a "CPU bound" process. However, you can make bash use some CPU time by running the following bash command, waiting a few seconds and killing it using Ctrl+C:
while [[ true ]] ; do : ; done

After that, you can check once more the CPU time spent by bash by running ps again.

I have written a simple script to display the total CPU time used by a process in milliseconds. Actually, on most systems the clock ticks 100 times per second, so the accuracy of the output is in tens of milliseconds. You can call this script by passing a single parameter specifying the process ID of the process you are interested, e.g. it will be 494 in your question.
#!/bin/bash
usage="Usage: $(basename $0) pid"
case "$*" in
 ''|*[!0-9]*)
  echo "$usage" 1>&2
  exit 1
  ;;
 * )
  pid="$1"
  ;;
esac
read -r -a pinfo <<< $(cat "/proc/$pid/stat" 2>/dev/null)
if (( ${#pinfo[@]} == 0 )) ; then
  echo -e "No proccess with PID : $pid" >&2
  exit 2
fi
let clk_tck="$(getconf CLK_TCK)"
let utime="${pinfo[13]}"
let stime="${pinfo[14]}"
let cputime=(utime + stime)*1000/clk_tck
echo "PID : ${pinfo[0]}
Cmd : ${pinfo[1]}
CPU : $cputime msec"


Installation Failed whilst installing UBUNTU 13.10

I came across this thread which may help:
http://ubuntuforums.org/showthread.php?t=1910258

Looking at errno 5, that indicates bad I/O (input/output.) If the above doesn't help, I would try to reformat the new drive in gparted since you can run Ubuntu from the disk, and maybe go as far as using fdisk to force the partition off, then go through gparted.

If that fails, I'd hook up the drive and try formatting it from another box, maybe with another OS for a 'second opinion', I like to call it, from another OS's point of view. If nothing then, I'd be worried about a bad logic board on the drive.


Why don't I have a password for "su"? Problems with "sudo"

1. Why you don't have a root password
While you can create a password for the superuser account allowing you to log in as root with su, it's worth mentioning that this isn't the usual way of doing things with Ubuntu (or increasingly, other distributions as well).  Ubuntu chose not to give a root login and password by default for a reason.  Instead, a default Ubuntu install will use sudo to give superuser privileges.  In a default Ubuntu install the person who installed the OS is given "sudo" permission by default.
Anybody with full "sudo" permission may perform something "as a superuser" by pre-pending sudo to their command.  For instance, to run apt-get dist-upgrade as a superuser, you could use:
sudo apt-get dist-upgrade

You will see this usage of sudo pretty much anywhere you read a tutorial about Ubuntu on the web.  It's an alternative to doing this.
su
apt-get dist-upgrade
exit

With sudo, you choose in advance which users have sudo access. There is no need for them to remember a root password, as they use their own password.  If you have multiple users, you can revoke one's superuser access just by removing their sudo permission, without needing to change the root password and notify everyone of a new password.  You can even choose which commands a user is allowed to perform using sudo and which commands are forbidden for that user.  And lastly, if there is a security breach it can in some cases leave a better audit trail showing which user account was compromised.
Sudo makes it easier to perform a single command with superuser privileges.  With su, you permanently drop to a superuser shell which must be exited using exit or logout.  This can lead to people staying in the superuser shell for longer than necessary just because it's more convenient than logging out and in again later.
With sudo, you still have the option of opening a permanent (interactive) superuser shell with the command:
sudo su

... and this can still be done without any root password, because sudo gives superuser privileges to the su command.
And similarly, instead of su - for a login shell you can use sudo su - or its shortcut sudo -i.
However when doing so you just need to be aware that you are acting as a superuser for every command.  It's a good security principle not to stay as a superuser for longer than necessary, just to lessen the possibility of accidentally causing some damage to the system (without it, you can only damage files your user owns).
Just to clarify, you can, if you choose, give the root user a password allowing logins as root as described in @Oli's answer, if you specifically want to do things this way instead.  I just wanted to let you know about the Ubuntu convention of preferring sudo instead and let you know that there is an alternative.

2. The problems with your chmod 777 -R command
Your question also has a second part to it: your issues with the command sudo chmod 777 -R foobs.
Firstly, the following warning indicates a potentially serious security issue on your machine:
sudo: /var/lib/sudo writable by non-owner (040777), should be mode 0700

This means that at some stage, you've set /var/lib/sudo to be world-writable.  I imagine you've done this at some stage using a command like sudo chmod 777 -R /.  Unfortunately, by doing this you've probably pretty much broken all file permissions throughout your system.  It's unlikely that this will be the only important system file whose permissions have been changed to be world-writable.  Essentially you have an easily hackable system now, and the only easy way to get it back would be to re-install.
Secondly, the command you were using:
sudo chmod 777 -R foobs

When manipulating files within your home directory, in this case in ~/Desktop, you should not have to use sudo.  All the files you create in your home directory should be modifiable by you anyway (and if not, something funny is going on).
Also, you need to be fully aware of the consequences of changing file permissions en masse, such as doing it recursively or on a huge number of files.  In this case, you're changing carefully set up file permissions to be world-writable.  Any other user, or any buggy server software on the machine, may have easy access to overwrite all of these files and directories.
It's almost certain that chmod 777 -R [dir] it is not an appropriate solution for whatever problem you were trying to solve (and as I mentioned above, there is evidence that you have done it to system files in /var/lib too, and I assume to lots of other places).
A couple of basic rules of thumb:

If you're just messing with your own files in your home directory, desktop etc, you should never need to use sudo or superuser rights.  If you do, it's a warning sign that you're doing something wrong.

You should never manually modify system files owned by packages.  Exception: unless you're doing it specifically in ways documented by those packages, such as by modifying their configuration in /etc.  This applies also to changing file permissions.  If a tutorial or attempt to fix the problem requires sudo or superuser rights, and it's not simply a change to a configuration in /etc/, it's a warning sign that you're doing something wrong.


Screen tearing when using i3, none when using unity

The Unity Shell UI is a plugin of the Compiz compositing window manager (Unity Wiki) while i3 a standalone window manager without native compositing features. That means that by default Unity utilizes all manner of graphics acceleration features and i3 uses "plain" X11.

In order to get compositing features in i3, you will have to start a composite manager (not a compositing window manager). compton is a quite popular choice to use with i3.

Installation is easy as packages for Ubuntu are available in the official repository for trusty and newer. After installation you have to create a configuration, for example at ~/.config/compton.conf (as the location of the configuration file can be passed as argument to compton, the choice is yours). My compton.conf looks like this:

# basic configuration
backend = "glx";
vsync = "opengl-swc";

glx-copy-from-front = true;
glx-swap-method = 2;
xrender-sync = true;
xrender-sync-fence = true;

# transparancy settings for i3
opacity-rule = [
    "0:_NET_WM_STATE@:32a *= '_NET_WM_STATE_HIDDEN'"
];

It is possible that you need to adjust it for your system.
Now you can start compton:

compton --config ~/.config/compton.conf -b

After you made sure that it works well, you can start it automatically by adding

exec --no-startup-id compton --config ~/.config/compton.conf -b

to your ~/.i3/config.

Note: I strongly suggest updating i3 to at least version 4.12 (the current release at time of posting). It solves a few rendering issues i3 has in conjunction with compton, at least when cairo ≥ 1.14.4 is available (xenial comes with cairo 1.14.6; see i3 Release Notes).


Why is the Web Preview in Geany slow to load?

Maybe a little late, but this refreshes the page every xx seconds, maybe that is usefull, change it to 3 for example and save and you only have to wait max 3 seconds and not have to switch between pages(if on 2 screens or something)

<meta http-equiv="refresh" content="xx">

(put it between the      head /head tags)

Arend-Jan


Can I use 14.04 MongoDB Packages with 16.04?

It's a bit of a hack but yes, this can be done. There is an undocumented step needed to actually start the service and (weirdly enough) unless you want to futz around with upstart job conversion manually, you need to install the Ubuntu mongodb package first, then remove it so that you have a usable service.  A straight install of the MongoDB packages will not give you a working service on a fresh 16.04.

Update - July 2016: The official fix for this (adding support for 16.04 to the packages) has been completed in the 3.3 dev branch as part of SERVER-23043 - and has been released as a backport in the 3.2 series as part of 3.2.7.  Hence, if you are using 3.2.7+ you do not need to do this and the official MongoDB package install should just work.

In any case, after doing the add/remove, follow the usual instructions for 14.04, summarized here:

# install the Ubuntu package (to get the service set up correctly)
sudo apt-get install mongodb
# Now remove it and continue with the MongoDB instructions
sudo apt-get remove mongodb
sudo apt-get autoremove
# import key
sudo apt-key adv --keyserver hkp://keyserver.ubuntu.com:80 --recv EA312927
# add trusty repos
echo "deb http://repo.mongodb.org/apt/ubuntu trusty/mongodb-org/3.2 multiverse" | sudo tee /etc/apt/sources.list.d/mongodb-org-3.2.list
# update apt
sudo apt-get update
# install the MongoDB package
sudo apt-get install -y mongodb-org

The install succeeds, and thanks to the Ubuntu package we have all the pieces needed for a service, but attempting to start the service will initially fail:

$ sudo service mongodb start
Failed to start mongodb.service: Unit mongodb.service is masked.

Fixing this is not too hard:

$ sudo systemctl unmask mongodb
Removed symlink /etc/systemd/system/mongodb.service.

Now we can enable/start the service, get its status etc.

$ sudo service mongodb enable
$ sudo service mongodb start
$ sudo service mongodb status
● mongodb.service - LSB: An object/document-oriented database
   Loaded: loaded (/etc/init.d/mongodb; bad; vendor preset: enabled)
   Active: active (running) since Thu 2016-04-14 16:40:35 IST; 7s ago
     Docs: man:systemd-sysv-generator(8)
  Process: 2849 ExecStart=/etc/init.d/mongodb start (code=exited, status=0/SUCCESS)
 Main PID: 1593 (code=exited, status=0/SUCCESS)
    Tasks: 13 (limit: 512)
   Memory: 51.9M
      CPU: 100ms
   CGroup: /system.slice/mongodb.service
           └─2861 /usr/bin/mongod --config /etc/mongodb.conf

Success - and we get a nice pointer to the active config file (which is in the old key=value format, see here for examples in the newer recommended YAML format).

Note: There will actually be two config files /etc/mongod.conf and /etc/mongodb.conf thanks to slight differences between the two packages we have installed.  The now-active service points to the old-format one by default /etc/mongodb.conf - you can switch by moving/copying the mongod.conf to mongodb.conf if you so wish, or simply edit the file directly.

Once started, to test, connect to the database with the mongo shell:

$ mongo
MongoDB shell version: 3.2.5
connecting to: test
Welcome to the MongoDB shell.
For interactive help, type "help".
For more comprehensive documentation, see
    http://docs.mongodb.org/
Questions? Try the support group
    http://groups.google.com/group/mongodb-user
Server has startup warnings:
2016-04-14T16:40:34.962+0100 I CONTROL  [initandlisten]
2016-04-14T16:40:34.962+0100 I CONTROL  [initandlisten] ** WARNING: Access control is not enabled for the database.
2016-04-14T16:40:34.962+0100 I CONTROL  [initandlisten] **          Read and write access to data and configuration is unrestricted.
2016-04-14T16:40:34.962+0100 I CONTROL  [initandlisten]
2016-04-14T16:40:34.962+0100 I CONTROL  [initandlisten]
2016-04-14T16:40:34.962+0100 I CONTROL  [initandlisten] ** WARNING: /sys/kernel/mm/transparent_hugepage/enabled is 'always'.
2016-04-14T16:40:34.962+0100 I CONTROL  [initandlisten] **        We suggest setting it to 'never'
2016-04-14T16:40:34.962+0100 I CONTROL  [initandlisten]
2016-04-14T16:40:34.962+0100 I CONTROL  [initandlisten] ** WARNING: /sys/kernel/mm/transparent_hugepage/defrag is 'always'.
2016-04-14T16:40:34.962+0100 I CONTROL  [initandlisten] **        We suggest setting it to 'never'
2016-04-14T16:40:34.962+0100 I CONTROL  [initandlisten]

If you wish to get rid of the THP warnings, check out this answer.


Alternative to Docker that is less restrictive for maintaining package dependencies

I think your best alternative for you is https://www.vagrantup.com/ (Their motto is "Development Environments Made Easy")

The following paragraphs are copied (with some editing) from their web site:

What is it for?
Vagrant is a tool for building and managing virtual machine environments in a single workflow. With an easy-to-use workflow and focus on automation, Vagrant lowers development environment setup time, increases production parity, and makes the "works on my machine" excuse a relic of the past.

If you are already familiar with the basics of Vagrant, the documentation provides a better reference build for all available features and internals.

Why Vagrant?
Vagrant provides easy to configure, reproducible, and portable work environments built on top of industry-standard technology and controlled by a single consistent workflow to help maximize the productivity and flexibility of you and your team.

To achieve its magic, Vagrant stands on the shoulders of giants. Machines are provisioned on top of VirtualBox, VMware, AWS, or any other provider. Then, industry-standard provisioning tools such as shell scripts, Chef, or Puppet, can automatically install and configure software on the virtual machine.

If you are a developer, Vagrant will isolate dependencies and their configuration within a single disposable, consistent environment, without sacrificing any of the tools you are used to working with (editors, browsers, debuggers, etc.) Once you or someone else creates a single Vagrantfile, you just need to vagrant up and everything is installed and configured for you to work. Other members of your team create their development environments from the same configuration, so whether you are working on Linux, Mac OS X, or Windows, all your team members are running code in the same environment, against the same dependencies, all configured the same way. Say goodbye to "works on my machine" bugs.

My experience:
I use vagrant on a daily basis and it solves all dependency problems. I run multiple VM for different projects on my depelopment computer. Also, you configure once and everybody get the same configuration. Simple, easy to use and
As a plus, you can use it with AWS


when gparted says the partition table is msdos does that mean MBR

Yes. From the GParted website:

  This article describes how to fix some common problems that cause an
  MSDOS partition table (also known as Master Boot Record - MBR) to be
  invalid.