If the hd LED is ON during the freez and it is a real and longer (about 45 seconds) one (no actions visible and every input is broken), please check first the hd's health with a SMART tool like Igsmartcontrol or smartmontools. I know, it's more like a comment, but I haven't got enough reputation.


What IP address does Ubuntu assign itself when it cannot reach a DHCP server?

Yes, Ubuntu does that, too, if you use NetworkManager to manage your network interfaces (that's the default for most graphical environments in Ubuntu).

It is a common standard defined in RFC3927 and used by most modern operating systems.


Ubuntu phone (bq aquaris) camera stopped working after system update

Did you receive a prompt asking you to allow the Camera app to access the phone camera?

If not, you can check in System Settings - Security and Privacy - Other application accesses - Camera, and confirm if the check item for Camera is ticked.


I believe that what you are asking for is how to manage Landscape server via CLI. Therefore I would like to point you to User Guide located here https://landscape.canonical.com/static/doc/user-guide/
This will be a good start.

With regards to CLI tools you would need to pick which one do you feel most comfortable with/ your preference:
https://landscape.canonical.com/static/doc/api/

And just to get you started there are 3 ways of using this API:

command-line client: easy to use, shell-script friendly

Python module: more powerful, recommended if you want to drive the API via Python

low-level HTTP requests: in the case you want to know what is going on, or write a client for some other language

My personal favourite is the command line client. Once you install landscape-api and source your keys ( you can find, generate and refresh them from Landscape server GUI, just click on your name when you are logged in) as per https://landscape.canonical.com/static/doc/api/api-client-package.html
you can get all the information from your Landscape server and attached machines:

example:

$ landscape-api get-computers | grep host
  u'hostname': u'xxx.eu-west-2.compute.amazonaws.com',
  u'hostname': u'xxx.eu-west-2.compute.internal',
  u'hostname': u'laptop',

$ landscape-api get-computers | grep ping
  u'last_ping_time': u'2018-12-05T16:45:39Z',
  u'last_ping_time': u'2018-12-05T16:45:39Z',
  u'last_ping_time': u'2018-12-05T15:24:20Z',

I am grepping here just to show you example as full output for even 3 machines is quite big especially if you run it with additional switches:

$ landscape-api get-computers --with-hardware

or

$ landscape-api get-computers --with-hardware --json

Then you can additionally parse that with jq for additional text manipulation

Hope this will help.


In Linux there are a variety of desktop or window managers, gnome, kde, xfce, lxde, fluxbox, openbox. Each desktop have various features.

See http://xwinman.org/

"Ubuntu" bu default uses Unity (gnome), and various versions use other desktops (kubuntu uses kde, xubuntu uses xfce, etc). See What kinds of desktop environments and shells are available?

Lenses are one of many features of unity, see

http://www.howtoforge.com/introduction-to-the-ubuntu-unity-desktop

http://www.howtogeek.com/112510/supercharge-ubuntus-unity-dash-with-lenses-scopes-5-lenses-to-install/


Ubuntu has got ext4 even if you boot it from USB drive. The software will only write the existing iso to your USB, you don't need to set up fs beforehand, it will be fat if that was the question.


Change your server location to Main Server and run the command sudo apt-get update. This helped in my case.


Multi-display Nvidia issue, desktop sliding on secondary display - Ubuntu 14.04

Extremely likely that you're hooking up the TV to an HDMI port.  However, the NVidia is the only graphics adapter that can service the HDMI port internally in your PC as the Intel can not.

What I do before hooking up the TV is to disable the Intel in my BIOS, then the NVidia takes over for everything, and when I unhook it from the TV, I reboot again and go back to Hybrid mode...

Crude, but effective!

(And if you wouldn't believe me: you can also disable the NVidia in the BIOS and then the output of lshw will not show the HDMI port any more!  ;-)


Using EasyDNS on a dedicated server - stuck

Please review these steps - Source

The default setup of Ubuntu does not make it easy to use static DNS servers while using DHCP.  If you use the standard ubuntu way of networking (ifupdown), you can edit /etc/network/interfaces In that file you find the entry for your interface. If your interface is eth0, then look for the following lines: auto eth0
iface eth0 inet dhcpAdd one line, so it looks like: auto eth0
iface eth0 inet dhcp
dns-nameservers ip.address.of.nameserverRun sudo invoke-rc.d networking restartTo make the changes effective If you do not use ifupdown, you need to edit /etc/dhcp3/dhclient.conf Find the lines #prepend domain-name-servers 127.0.0.1;
request subnet-mask, broadcast-address, time-offset, routers,
        domain-name, domain-name-servers, host-name,
        netbios-name-servers, netbios-scope;And change them to prepend domain-name-servers 1.2.3.4, 1.2.3.5;
request subnet-mask, broadcast-address, time-offset, routers,
        domain-name, host-name,
        netbios-name-servers, netbios-scope;Replace 1.2.3.4 and 1.2.3.5 with the addresses of your DNS servers. Run sudo invoke-rc.d networking restartTo make the changes effective:


Make global application menu replace titlebar in gnome-panel

i think you want this

http://pkgs.org/ubuntu-10.10/webupd8-i386/gnome-window-applets_0.2.10-1~webupd8~maverick_i386.deb.html

if you experience applets moving unintentionally you should consider the complete lock down all panels option in

ubuntu tweak -> GNOME Settings -> complete lockdown of all panels

if you dont have ubuntu tweak you can get it at the software center...


This website contains the information you are looking for. Clonezilla is a Free and Open-Source alternative to Norton Ghost.

http://clonezilla.org/


Tell us what kind of graphics are you using?
If you are using widely used nvidia, then the driver needs to be updated.Give the following command in the terminal

$sudo apt-get <drivername>-current

Here driver name will be nvidia.
Now you need to configure the driver from additional driver in dash home by activating them.
And for the second problem.Give the command

$sudo apt-get -f install

And then give

$sudo apt-get update


Go to Setup - IBus-Anthy either via the third button on the bar you want to get rid of, or via Dash > Text Entry > [single click] Japanese Anthy > [click on settings bottom right].

You can choose what parts of the menu should display next to your cursor, when Anthy is active, in the settings's General tab under Menu visibility on Status Icon. Uncheck all boxes (in your case Input mode, Dictionary mode, Preferences - Anthy) and the menu should disappear.


This is accurate. The issue is the updated ni-babel 2.1

This solves the error:

  No such file: ''
  Traceback (most recent call last):
    File "/usr/local/bin/melview", line 9, in
      load_entry_point('melview==1.0.1', 'console_scripts', 'melview')()
    File "build/bdist.linux-x86_64/egg/melview/melodic_traits.py", line 863, in main
    File "build/bdist.linux-x86_64/egg/melview/melodic_traits.py", line 514, in init
  nibabel.py3k.FileNotFoundError: No such file: ''

In Xubuntu 14.04 with neurodebian:

to fix:

sudo apt-get update

sudo apt-get install python-nibabel=1.2.2-1

sudo apt-mark hold python-nibabel


14.04 crash - blank desktop icons, toolbar icons and menu icons, no desktop button on login

This helped:

sudo apt-get install libgdk-pixbuf2.0-dev
sudo gdk-pixbuf-query-loaders --update-cache


503 Service Unavailable and 504 Gateway Timeout are tracker server responses.

Transmission did connect to the tracker but it failed to respond correctly. It's either overloaded or down. Try another tracker or torrent and see if it helps.

See List of HTTP status codes.


Remove the driver that you installed, if do you have a fresh ubuntu install without data, please reinstall it, else try to uninstall the driver.
Assuming that do you have a wired, connection, connect it.
Install the package b43-fwcutter from the Software Center or with the command sudo apt-get install b43-fwcutter
Reboot


After upgrade to 18.04, cpufreq scales all CPUs in unison rather than individually

The main thing for your processor is that there is only one Phase Locked Loop (PLL - which scales the CPU clock up and down) in the processor package. Therefore it has always been the case that the CPUs scale up and down in unision. The reason it used to seem different was that the acpi-cpufreq CPU scaling driver used to report what it thought the CPU frequencies should be rather than what they actually were. Now it reports what the frequencies actually are.

For almost all users / scenarios using cat /sys/devices/system/cpu/cpufreq/policy*/scaling_cur_freq provides a good enough indicator as to what the individual CPU frequencies are. The reason the document has that disclaimer line it that it is possible that the information can be a little stale if a CPU has been idle with its clock stopped for awhile.

By default your processor should be using the intel-pstate CPU frequency driver and it has HWP (Hardware pstate control), meaning the processor itself can decide the requested pstate (CPU frequency). Note that all pstate requests to go into the PLL stuff, along with idle states and a decision is made as to at what pstate the PLL will operate. You seem to be using the acpi-cpufreq CPU scaling driver, so I guess you have disabled the intel_pstate driver, which is fine, if that is your preference.

As for CPU frequency scaling tools / methods. I never use them. I only manage CPU frequency scaling with the basic primitive commands via the command line.

As to why your CPUs do not seem to go into the turbo range now, we would need more information to provide help. Starting with, for example:

doug@s15:~$ grep . /sys/devices/system/cpu/cpufreq/policy*/scaling_driver
/sys/devices/system/cpu/cpufreq/policy0/scaling_driver:intel_pstate
/sys/devices/system/cpu/cpufreq/policy1/scaling_driver:intel_pstate
/sys/devices/system/cpu/cpufreq/policy2/scaling_driver:intel_pstate
/sys/devices/system/cpu/cpufreq/policy3/scaling_driver:intel_pstate
/sys/devices/system/cpu/cpufreq/policy4/scaling_driver:intel_pstate
/sys/devices/system/cpu/cpufreq/policy5/scaling_driver:intel_pstate
/sys/devices/system/cpu/cpufreq/policy6/scaling_driver:intel_pstate
/sys/devices/system/cpu/cpufreq/policy7/scaling_driver:intel_pstate
doug@s15:~$ grep . /sys/devices/system/cpu/cpufreq/policy*/scaling_governor
/sys/devices/system/cpu/cpufreq/policy0/scaling_governor:powersave
/sys/devices/system/cpu/cpufreq/policy1/scaling_governor:powersave
/sys/devices/system/cpu/cpufreq/policy2/scaling_governor:powersave
/sys/devices/system/cpu/cpufreq/policy3/scaling_governor:powersave
/sys/devices/system/cpu/cpufreq/policy4/scaling_governor:powersave
/sys/devices/system/cpu/cpufreq/policy5/scaling_governor:powersave
/sys/devices/system/cpu/cpufreq/policy6/scaling_governor:powersave
/sys/devices/system/cpu/cpufreq/policy7/scaling_governor:powersave
doug@s15:~$ grep . /sys/devices/system/cpu/intel_pstate/*    <<<< If driver is intel-pstate.
/sys/devices/system/cpu/intel_pstate/max_perf_pct:100
/sys/devices/system/cpu/intel_pstate/min_perf_pct:42
/sys/devices/system/cpu/intel_pstate/no_turbo:0
/sys/devices/system/cpu/intel_pstate/num_pstates:23
/sys/devices/system/cpu/intel_pstate/status:active
/sys/devices/system/cpu/intel_pstate/turbo_pct:18

Anticipated question: If there is only one PLL, and all CPU always operate at the same frequency, then why are different frequencies reported for them? Example:

doug@s15:~$ cat /sys/devices/system/cpu/cpufreq/policy*/scaling_cur_freq
2186018
2315657
2308037
2254830
2111971
2127314
2169466
2152378

Answer: In any given measurement interval, the CPUs are also going into and out of various idle states, where, if the idle state is deep enough, the CPU clock is stopped. The reported frequency is the average active frequency for that processor over the last measurement interval.


How to add right click format option to a disk icon in the launcher?

Run sudo apt-get install nautilus-actions

Search nautlilus-actions in the dash

Open it

Enter the information as follows:

Action Tab

Nautilus Item - mark Display Item in selection context menu

Context Label - Format Disk

ToolTip - Format Removable USB & SD Media

Icon - browse to /usr/share/icons/gnome/48x48/apps/file-manager.png and select (this is
just what i used, you may choose something different(

Action Properties - Enabled

Command Tab

Profile - Default Profile

Command - gksudo gnome-format

Parmeters - Blank

Folders Tab

Should already have / listed

Restart your computer

Finally open nautilus and right click any empty space in the directory that you want to format

Select nautilus actions

Select Format Disk

I hope this helps!


How to permanently unhide the application menu?

You can set the environment variable UBUNTU_MENUPROXY=0 before you log in. If you only want to deactivate it or enable it for a single application, then you can do things like UBUNTU_MENUPROXY=0 gcalctool. Use 1 instead of 0 to enable.


What is the best stable ppa for Nouveau?

Solved. Xorg-edgers worked the best for me.

sudo add-apt-repository ppa:xorg-edgers/ppa


Mysterious icon after kubuntu... which app?

As Jos mentioned, I checked all the processes running, and killing klipper solved the issue. It seems that removing kubuntu-desktop leaves behind klipper in startup applications, which creates the icon in the panel, but it doesn't do anything. Removing it from the start up applications solved the issue.


Is there a way to make Xorg only programs open on Wayland?

Technically speaking, yes. Actually there are more Xorg programs running in your Wayland session than you think, like Google Chrome and Firefox.
This is thanks to XWayland server, a backward compatibility implementation in Wayland that allows running legacy X programs in Wayland. And it is already configured in your Wayland session.

  I do I find certain programs such as Gufw will not open, and will only work under the Xorg session

Note that graphical applications that need to run as root such as gufw and gparted no longer work under Wayland, as a security mesure, and therefore they won't launch with XWayland too.

There is a way to bypass this security measure and launch gufw and such applications under Wayland but its not recommended, and that's by adding root user to xhost access control list:

xhost +SI:localuser:root

To automatically launch this command in every session after login, you can refer to this answer.

Hope this answers your question about running Xorg programs on Wayland.


Broken JRE installation, any advice how to fix?

Here's the answer: make a symlink from /usr/bin/update-alternatives to /usr/sbin/alternatives, use dpkg --purge, then delete the symlink:

https://stackoverflow.com/questions/33635075/remove-broken-java-installation-linux


Download Manager With Slow Download Speed Ubuntu 14.04

You need to do more in these applications than IDM, for example in IDM they try to use as many connections as possible (this can actually get you banned from some servers) whereas uGet default is to use 1. Edit your settings for uGet to use more connections for the file you are trying to download.

As for the auto-load thing, sure. FlashGot add-on for Firefox can do this.

For example set the default option in FlashGot to be uGet and then download something. The popup that asks to complete download also has a check box to remember that setting, check that and the next time it will auto-load uGet.


The default permission for /var/www itself is a pretty standard one: owner root:root and mod 755.

As for anything inside /var/www, that is one of the rare directories where you have the privilege of deciding for yourself what to put in it and what permissions everything in it should have.  But what makes the most sense is:

Most files should be writable by whichever user or group is going to be writing to them most.  You can set them to be owned by your user account.  Or set up a custom group for your developers.  Or if the files will be modified rarely and you want good security, you can go with root:root and just sudo in on the rare occasions they'll be modified.
Most files should not be world-writable.  So, 644 for files, and 755 for directories is appropriate (or 664 and 775 if you want to give a group write access).
It is not recommended to set any of it to be writable by the web server, ie www-data, except for any specific files your web scripts to be able to write to.  If so, it's better to set the user or group of those files to www-data than to make them world-writable.  Note that any time the www-data user can write to any file within the web root, whether it's by setting the user or group on those files, or making them world-writable, it's a potential security problem.  World-writable is just the worse of the two.


Should media files (HTPC) using NFS mount using fstab/static or autofs?

I have used static mounts for years for media files with good results since we want them highly available. However we have a dedicated HTPC/MediaServer runinning 24/7 (it takes backups at night from the destops too). I've thought AutoFS seemed complicated vs just mounting the server partitons in fstab and letting them run. I don't like switching harddisks off and on.

I wonder why your mounts are behaving like this? is something odd about how you've setup your nfs4 mounts? I think I fixed a similar problem with the 'crossmnt' option on the parent directory in the /etc/exports entry. The child mounts would be delayed for a while after I opened the parent export folder. I think with the crossmnt option on the top level /etc/export entry; the child mounts popped up quickly but it has been a while since I solved that issue.

Listing your /etc/exports would help.

On the client side:

$cat /proc/mounts | grep nfs4

will show all the client nfs4 mount options you are ending up with.

This from might help you from nfs - fstab format and options for the nfs file systems

   bg / fg        Determines  how  the  mount(8)  command  behaves  if  an
                  attempt  to mount an export fails.  The fg option causes
                  mount(8) to exit with an error status if any part of the
                  mount  request  times  out  or  fails outright.  This is
                  called a "foreground" mount, and is the default behavior
                  if neither the fg nor bg mount option is specified.

                  If  the  bg  option  is  specified, a timeout or failure
                  causes the  mount(8)  command  to  fork  a  child  which
                  continues  to  attempt  to mount the export.  The parent
                  immediately returns with a  zero  exit  code.   This  is
                  known as a "background" mount.

                  If  the  local  mount  point  directory  is missing, the
                  mount(8) command acts as if the mount request timed out.
                  This  permits  nested NFS mounts specified in /etc/fstab
                  to proceed in any order  during  system  initialization,
                  even   if  some  NFS  servers  are  not  yet  available.
                  Alternatively these issues can  be  addressed  using  an
                  automounter (refer to automount(8) for details).


I cannot get GRUB2 to boot in an Acer Spin SP315-51, and I need it, Dual-booting with Windows 10

I had forgotten about this post; anyhow, none of the usual answers worked for me. Instead there was an option in the UEFI menu that said "add option to UEFI boot" (or something along the lines of it) from there I was able to add the Grub menu. I hadn't seen this answer anywhere, I assume not many computers have it or simply don't require this option. Either way, thanks. I hope someone who comes across this finds it useful.


Replace command output with custom error message

Add this line to your ~/.bashrc file:

alias ls="echo sorry ls command not found"

You can do that simply with echo:

echo 'alias ls="echo sorry ls command not found"' >>~/.bashrc

Every newly opened terminal will now print your error message when you run ls:

$ ls
sorry ls command not found

If you want to call the actual ls, use one of the following approaches to bypass the alias:

/bin/ls
\ls
command ls


How do I get a Broadcom BCM43225 wireless card working?

Plug into ethernet and run the following commands:

sudo apt-get install linux-firmware-nonfree
sudo apt-get install linux-headers-generic
sudo apt-get install bcmwl-kernel-source
sudo modprobe -r b43 ssb wl
sudo modprobe wl

After a few seconds wireless activated and detected my newtork. (The above commands were run by using wired network of course)


15.04 to 15.10 upgrade no USB, Ethernet, Wireless

I had a similar issue when installing 15.10 server (no GUI). This has to do with Ubuntu not recognizing your network card. I found several LENGTHY links which should help you set it up. I am not a professional, I am just an amateur so I apologize if this information is old for you.
Ubuntu 14.04 Server - WiFi WPA2 Personal
how to connect to a wifi (wpa/wpa2) in ubuntu server 14.04
http://ubuntuforums.org/showthread.php?t=318539
http://ubuntuforums.org/showthread.php?t=571188


Fonts screwy in toolhints, Select list items on multiple browsers and many apps

SOLVED: A new software update was waiting for me today. Installed, rebooted, and the problem is gone. Yay!! Something to do with xserver video hwe bug in the previous update, as I understand.


You should never use 9.04 as it is old and has security holes. Also, being old, the Virtualbox in the repositories for it has not been updated so it is also full of bugs. 12.04 will do fine to run Virtualbox with a guest.

You can opt to use Unity 2D if you are having low graphics performance on the host, by clicking the circle when you are prompted for your password at login and selecting Unity 2D.

If it is still too slow, you can use 10.04 as it has somewhat less RAM usage while being more up-to-date, or you can install an alternate desktop enviromnent. Lubuntu appears to use the least RAM, and if you are taking this route, there is no need to use 10.04 and you can use 12.04 without concern for performance.

With that said, you will still have issues of you don't have enough RAM(at least 1 GB is recommended, but you can make do with 768MB), no matter what version you use.


Please ... repeat after me and keep in mind:
No, I do not want to remove gcc-5-base!
You never did install gcc-5-base: the package is installed by Ubuntu and it has to be kept installed or otherwise Ubuntu will cease to function!
As you don't seem familiar with Ubuntu: What you're asking for is similar to removing the system32 from the Ẁindows directory!


Dell E6500 wireless not working after fresh installation of ubuntu 12.04

Easy do this in terminal, it will work:

sudo apt-get install linux-firmware-nonfree
sudo modprobe -r b43
sudo modprobe b43

Voila, it works.


Problem Booting from USB Stick on Old Dell Laptop

I too have a very old Dell (Inspiron 1000) and it recognizes the flash drive as another hard drive.  Go to the BIOS and you will notice a + by the hard drive entry.  Click on that and you will see the flash drive.  Simply move it to the top, save, and exit.  You will then be able to boot from the flash drive.


The command "setterm" can be used to change the background color of consoles. There are many parameters that can be changed. Try this to get started:

setterm -background red
clear

Then have a look at man setterm to see what else you can play with.


A WiFi connection is a common issue that can be either a software or a hardware issue. In Ubuntu, the NetworkManager makes the connection to wifi without you having to perform any manual task. At times however unexpected things might occur and you will have to configure or adjust the connection settings by yourself.

You first need to make sure that the problem is not related to the router or the modem. Try first to reboot these devices before proceeding to the troubleshooting steps. You might also want to verify your computer WiFi switch in case you have a laptop for instance.If you have a mobile phone or another PC, make sure the wifi connection is up and running and that the signal is strong enough.

Remember when you boot your computer to configure the automatic connection to a wireless network or a wired one in the NetworkManager.
the answer to this question can be very long - you can check this guide for instance. It might help you out...


Lubuntu Netbook shows root partition full

It resolved after I restarted my computer.


Does Home Encryption used in addition to Disk Encryption increase security?

I'm going to say overkill. You incur a penalty in performance for the decryption twice, while only gaining a marginal increase in security. If an adversary is able to bypass the full disk encryption in some way, by stealing the keys from memory, using a keylogger or just beating it out of you with a wrench. Then breaking any secondary encryption is only going to take a bit more effort, because the same method can be used again.

If only considering Full disk encryption vs a file system encryption. Then FDE is more secure, because a filesystem encryption usually only encrypts the files, so filesystem metadata is still available (number of files, size of files, access data). Depending on the particular system used, the filenames might not be encrypted either.


This ought to do it:

sudo gedit /etc/default/grub
Find this line: GRUB_CMDLINE_LINUX=""
Change it to GRUB_CMDLINE_LINUX="iommu=soft"
Save
Reboot


Problems with network adapter within VM Virtualbox

Solved: Long ago I created a script that ran at startup. It started the VPN. It seemed broken. But after changing the vpn, it cause the issue. Deleted it and BOOM.


Lost Power during Krita installation from terminal. Now cannot install anything because of dpkg error

Got the answer from the half installed packages post
Just had to reinstall the packages using the following command:

sudo apt install --reinstall <package name>

Thanks for the help guys.


Can't switch to dedicated nVidia graphics card

There is a known bug to nvidia settings: Bug #1341140.

If you receive the following error message, you are probably affected by it:

ERROR: nvidia-settings could not find the registry key file.
This file should have been installed along with this driver at either
/usr/share/nvidia/nvidia-application-profiles-337.25-key-documentation or
/usr/share/nvidia/nvidia-application-profiles-key-documentation.
The application profiles will continue to work, but values cannot be preopulated
or validated, and will not be listed in the help text.
Please see the README for possible values and descriptions.

There is a workaround to this bug, also contained in the bug report. Execute the following from a root shell, replacing the 340.24 by the actual driver number. (I yet have to find out what they mean...)

mkdir -p /etc/nvidia
cd /etc/nvidia
ln -s /etc/alternatives/x86_64-linux-gnu_nvidia_app_profile_keys nvidia-application-profiles-340.24-key-documentation
ln -s /etc/alternatives/x86_64-linux-gnu_nvidia_app_profile nvidia-application-profiles-340.24-rc

Now the problem should be fixed, according to the bug report.

EDIT: The OP mentioned that he had to alter above commands as follows:

cd /usr/share/nvidia
mv nvidia-application-profiles-340.76-key-documentation nvidia-application-profiles-key-documentation
mv nvidia-application-profiles-340.76-rc nvidia-application-profiles-rc


You have to go on the menu bar (black stripe on the top of the screen) and hover the mouse there. Menus will appear, including "Edit".

You can also modify the software sources by going to the update manager and then go to  "Settings", the button on the bottom left. Once there you will be asked the password to proceed.

Place your mouse there at black color marked area , you will get menu . Hope that helps .


Synaptic corrupted, not able to install anything even from terminal

it seems that you stopped the process of installing/upgrading prematurely, so package manager wants to correct the situation. You have run what it says: "sudo dpkg --configure -a". After that completes, everything will probably be OK. If the problem persists post the console output here.


Unable to lower screen brightness when Night Light is ON

I control this using the Gnome Extension Adjust Brightness Icon

This places a lightbulb icon on the top bar which, when you click on it adjusts the screen brightness in steps.

The cycle is 4 steps; the 4th step returning the screen to it's native state.

If you are not certain about installing Gnome Extensions Navigate your Firefox browser to https://extensions.gnome.org/ and simply search for Adjust Brightness Icon extension. Flip the ON switch to install the extension. Complete the installation of the extension by clicking on the ON switch then click Install to confirm.


Try this to clear up the errors you're getting and install the older version.

$ sudo apt remove --purge skype
$ sudo apt update
$ sudo apt upgrade
$ sudo apt install skype

The latest version of Skype:

Alternatively install the Latest Skype from skype.com.  It currently has more support from Microsoft (the new owners of Skype), as well as support for many features the older version doesn't have.

Installation is simple.  Grab the skypeforlinux-64-alpha.deb package.  Click on it and install from the software center.  Or via the commandline with:

$ sudo dpkg -i skypeforlinux-64-alpha.deb


You can use the 'Swiss Army Knife' gnome-disk-utility to create the Windows installation media. Open Disks from the dash and select Restore Disk Image from the menu on the top right of the application. Choose the Windows installation file and the USB drive to write it to. Click Start Restoring, now you should be able to boot from the Windows USB media properly.


How to synchronize entire thunderbird profile with Ubuntu-One?

I have not used Ubuntu One (I use Dropbox), but this should be possible: Open the file manager (Nautilus), enable viewing hidden files and folders, right click on the .thunderbird folder in your home directory, and enable syncing to Ubuntu One.

If you are using Thunderbird on two (or more) machines and sync both the profiles to Ubuntu One, there could be problems with both machines performing conflicting writes on the profile. But as long as it's synced from only one machine, it should be fine. Do keep in mind the storage space limit on Ubuntu One.


Installing multiple Ubuntu distros via wubi?

The different Ubuntu flavours just install different packages per default. If you installed let's say Xubuntu but also want to have everything installed that would have come with Kubuntu, simply install the kubuntu-desktop package in Xubuntu. You can then select the session to use on the login screen.


When is the next point release to be available?

According to the official Ubuntu wiki it will be released August 23rd 2012.

Precise release schedule


If you're certain you don't need those folders then using sudo privileges you should be able to delete the folders as you would do any others.

sudo rm -r /var/www/Documents/

If you're concerned about doing this then look into a .htaccess file to prevent other people from being able to view your folders.


sending message to printk buffer from user space -- not working

Use:

echo "<1>Writing critical printk messages from userspace" | sudo tee /dev/kmsg

See this answer to understand why.


A reboot solved it. As mentioned logging completely out and in again did not help.


Offline Installation of Chrome: target doesn't exist

You always install .deb files by opening a terminal (Ctrl+Alt+T) and running the command:

sudo dpkg -i /path/to/file.deb

For example:

sudo dpkg -i ~/Downloads/google-chrome-stable.deb

You should never just extract the binary files from the archive and try to run them. This may work for very simple applications, but is usually predetermined to fail.

Or, whenever possible, use the Ubuntu Software Center to download and install software without any trouble.


lubuntu.net is one of many 'fan' sites which are not related to Ubuntu, or Lubuntu teams.   They do provide their own downloads, however most of their downloads do point to official ubuntu servers so it's on you to verify it's an official download (and not something else as it's not an official site).

If you use google.com to look for sites; you'll often find the fan sites listing above official sites, and the site at the top will most likely be one that uses your own language (the official site is really english based, so it's more noticable if you don't use english and a fan site is available in your own tongue).

If you don't know which is the official site, I'd suggest going to ubuntu.com and looking there. You'll end up at https://ubuntu.com/download/flavours which will point you to the official Ubuntu flavor site.

For Lubuntu it's http://lubuntu.me/

I'd trust the site which is controlled by the Lubuntu team, and monitored by Ubuntu, as against alternate sites which are not.

FYI:  Lubuntu isn't trying to encourage Lubuntu 19.04 installs at this very late stage of it's life, it's EOL is approaching very fast, so why would you want to install an OS that reaches EOL in a few weeks?  (https://lubuntu.me/disco-released/, http://fridge.ubuntu.com/2019/04/19/ubuntu-19-04-disco-dingo-released/ EOL = end 18-Jan-2020)


Installing a config file for a new service added to systemd/system dir

/etc/sysconfig is coming from the Red Hat world, in debian/ubuntu world /etc/default is usually used.

Now the question is, does the systemd .service file explicitly reference /etc/sysconfig? if so I would just create the directory (with mode 0755) and put the file there to avoid modifying the service IBM is shipping and call it a day.

If you really want to follow the debian/ubuntu "standards" you could also have a look at systemd drop-ins to override the directive without modifying the complete file.


sudo apt-get install qttools5-dev-tools

solved the problem.

The designer is included in the package "qttools5-dev-tools".

[$ nbviewer]$ apt-file search /usr/lib/x86_64-linux-gnu/qt5/bin/designer
qttools5-dev-tools: /usr/lib/x86_64-linux-gnu/qt5/bin/designer


Before I answer your question, a word of advice: consider changing the default Ubuntu desktop (which is quite resource heavy) to something more lightweight. Lubuntu or Xubuntu both seem to be good alternatives. You can install them with

sudo apt-get install lubuntu-desktop

and

sudo apt-get install xubuntu-desktop

respectively.

Yes, you can change the size of your partition and create a new one using a program called gparted.

However, you should boot the computer from the LiveCD or USB installation (with the "try Ubuntu" option), because you cannot modify partitions which are in use.

After you have used gparted (which is pretty intuitive, but google if you have any problems) and your swap has been successfully created (remember to tell gparted to format the partition as Linux swap!), you will have to boot modify the /etc/fstab file to tell it to use the new swap partition.

You can do it either from the LiveCD, or from the running system. The second one, in its least efficient, but simplest form is this: boot into your system, open the /etc/fstab file:

gksudo gedit /etc/fstab

Put a comment char (#) in front of the line (if there is one) which refers to swap. Add another line like that:

UUID=2xx52d6-12b6-4457-bc4e-24ac7fe64176 none             swap    sw              0       0

Where to get this UUID thing? Type the following command

sudo blkid

It will list all partitions and their respective UUID's. The one which is swap will have TYPE="swap".

Ask if you have any further questions.


Automatic uncompressed backup/folder syncing to smb share

A GUI is simpler to use but less versatile than your own script, so to have everything you want exactly the way you want it, cron and rsync is the way to go as you can still execute the script manually whenever you want.  All GUI backup programs that I'm aware of compress, deduplicate, encrypt, ...

If you want an icon for your script you can still do that too.


Stuck on extremely low resolution 800x600; Native Resolution 1680x1050

Working on it all day, I've come to the conclusion that problem lies solely in the monitor, VX2025wm's have a history of problems for the EDID and DVI Input, such as not showing native resolution, Signal Not Found errors, and a bunch of other messy little things that aren't conducive to a fluid computing environment.

The solution lied in adding a Custom EDID to the xorg.conf file:

Option         "CustomEDID" "DFP-0:/etc/X11/viewsonic.raw"

For this specific monitor, I was able to find the EDID here:
http://blog.komeil.com/2008/06/fixing-edid-dvi-monitors-no-signal.html

I hope this helps anyone who is having problems with their native resolution and is certain that their Graphics Cards / Drivers are not the problem.

Example: xorg.conf

Section "InputDevice"
    Identifier     "Razer Naga"
    Driver         "mouse"
    Option         "Protocol" "auto"
    Option         "Device" "/dev/psaux"
    Option         "Emulate3Buttons" "no"
    Option         "ZAxisMapping" "4 5"
EndSection

Section "InputDevice"
    Identifier     "Razer Lycosa"
    Driver         "kbd"
EndSection

Section "Monitor"
    Identifier     "VS10859 ViewSonic Widescreen"
    VendorName     "ViewSonic"
    ModelName      "DFP-0"
    HorizSync       30.0 - 82.0
    VertRefresh     50.0 - 75.0
EndSection

Section "Device"
    Identifier     "GTX 660 Ti"
    Driver         "nvidia"
    VendorName     "NVIDIA Corporation"
    BoardName      "GeForce GTX 660 Ti"
EndSection

Section "Screen"
    Identifier     "Primary Screen"
    Device         "GTX 660 Ti"
    Monitor        "VS10859 ViewSonic Widescreen"
    DefaultDepth    24
    Option         "nvidiaXineramaInfoOrder" "DFP-0"
    Option         "CustomEDID" "DFP-0:/etc/X11/viewsonic.raw"
    SubSection     "Display"
        Depth       24
    EndSubSection
EndSection

Section "ServerLayout"
    Identifier     "Default Layout"
    Screen         "Primary Screen"
    InputDevice    "Razer Naga" "CorePointer"
    InputDevice    "Razer Lycosa" "CoreKeyboard"
    Option         "Xinerama" "0"
EndSection


How can I find the runlevel of the processes of /etc/init.d?

Run:

cd /etc/init.d
grep Default-Start *

Results:

dbus:# Default-Start:     2 3 4 5
docker:# Default-Start:      2 3 4 5
gdomap:# Default-Start:     2 3 4 5
...

Just to note, from man runlevel:

   ┌─────────┬───────────────────┐
   │Runlevel │ Target            │
   ├─────────┼───────────────────┤
   │0        │ poweroff.target   │
   ├─────────┼───────────────────┤
   │1        │ rescue.target     │
   ├─────────┼───────────────────┤
   │2, 3, 4  │ multi-user.target │
   ├─────────┼───────────────────┤
   │5        │ graphical.target  │
   ├─────────┼───────────────────┤
   │6        │ reboot.target     │
   └─────────┴───────────────────┘


Wake-on-LAN quit working with latest kernel (Bionic)

To make this persistent I created a script in /etc/network/if-up.d

#!/bin/sh

/sbin/ethtool -s [card] wol g

This re-enables WoL every boot.


Could not scan some of the folders contained in “/” (Permission denied)

Your user does not have permission to read what is contained in other users' home folders, and you don't have permission to read some files created by other users. You also do not have permission to read some system files.
In order to get permission, you need to call for superuser privileges.  You can launch the application as the root user by adding sudo before the command to launch the application.
This looks similar to filelight.  If that's what you're using, run sudo filelight in a terminal.  Replace filelight with the name of the application you want to run as the root user.
Please note that with superuser privileges, you are giving that application the ultimate power to read, write, execute, and destroy.  Be careful what you are doing. It's often recommended that you not run file manager type applications as the root user.  Determine whether it is really necessary that you give your application access to those files.


1) My experience I've not had any GUI issues using the NVIDIA drivers, though I have experienced less stability. As for safe, you should be able to just uninstall the nvidia drivers if you have problems and it should revert to using nouveau drivers again.

2) Installing NVIDIA drivers should add NVIDIA X Server Settings, which will allow you to select which GPU should be used. From the last time I used this the NVIDIA drivers by themselves only allows you to select one to use and a relogin is needed to switch. There's stuff like bumblebee and a few others that allows you to run on intel graphics by default and specifically run programs on the nvidia gpu.

3) Specifically for your use case I don't know, but look into bumblebee.


How to add nested columns in a LibreOffice writer table?

Follow these steps:

With the cells selected, go to Table → Split Cells....

On the Split Cells window input the desired number of cells you want to split them to, select the desired split direction and click OK.


wireless connection only after power off

Netplan thinks it is in charge but you haven't any declaration for wireless. Network Manager thought it was in charge until you removed it. Wicd thinks it is in charge but, obviously, isn't.

I suggest that you decide whether wireless or ethernet is your preferred method of connecting and configure that and only that interface.

Assuming, because of the subject of your question, that it is wireless, I suggest that you amend your /etc/netplan/01-netcfg.yaml file to read:

network:
  version: 2
  renderer: networkd
  wifis:
    wlx00e04c195779:
      dhcp4: yes
      dhcp6: yes
      access-points:
        "network_ssid_name":
          password: "**********"

Please note that the network name, or SSID, and the password are enclosed in quotes ". Netplan is quite strict about spacing, indentation, etc. Please proofread carefully twice.

Follow with:

sudo netplan generate
sudo netplan apply

Reboot and test.


To solve your problem install the latest stable NVIDIA drivers 355.

But first uninstall every NVIDIA related software you have had installed before.

This includes removing the bumblebee packages as well, they will be replaced with nvidia-prime.

Open a terminal and execute:

sudo apt-get purge nvidia* bumblebee
sudo reboot

Then (re)-install the NVIDIA drivers:

sudo add-apt-repository ppa:graphics-drivers/ppa
sudo apt-get update
sudo apt-get install nvidia-355 nvidia-prime
sudo reboot

Switch between intel and nvidia graphics by using NVIDIA X Server Settings -> Prime Profiles.

Note : In case you used any GPU drivers related PPA's - purge them before installing as well !


I have a few versions of Python on ubuntu 16.04 LTS -> how to remove some and not to break down the system

When Python 3.6.1 is installed via ./configure -> make -> make install, it should be uninstalled by running make uninstall from the same directory.


cant find a driver for HP AMD Radeon HD 6450 512MB PCIEX16 for Ubuntu 14.04 LTS

Checking on unofficial ATI graphics wiki, saw tour hardware in supported list. http://wiki.cchtml.com/index.php/Hardware

Please follow The steps listed here: http://wiki.cchtml.com/index.php/Ubuntu

Good luck.


after upgrade from ubuntu 14.0 to 16.0 bootscreen comes black on desktop

Around some time back I upgraded my system from Ubuntu 14.04 (Trusty Tahr) to Ubuntu 16.04 (Xenial Xerus). During the upgrade procedure I had erroneously rebooted and had faced a similar problem, although in my case the screen wasn't blank, but instead was this. Running this command helped me restore my system, and after rebooting I finished the remaining upgrade from the Ubuntu Software Centre. I hope this helps


Is there a faster way to download Ubuntu?

I find the bit torrent downloads to be MUCH faster than the direct links.

Check out http://www.ubuntu.com/download/desktop/alternative-downloads and select the desktop version you need (i386 is 32bit ubuntu; amd64 is 64bit ubuntu).


Make a new archive once per minute using "crontab"

cron treats % as newlines. You need to use escape it i.e. use \% to get literal % as used in date.

So you need:

date +"\%Y\%m\%d\%H\%M"

Or you can use a script and use all the commands in the script and call the script from crontab.

From man 5 crontab:

  Percent-signs (%) in the command, unless escaped with backslash (\),
  will be changed into newline characters, 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 "\".


What's the difference between USB, UUID, Disk identifier and Vendor ID?

Lets take these in turn:

Disk Identifier:

This applies to an entire hard disk drive (not a single partition). A Disk Identifier/Disk Signature is a 4-byte number that is randomly generated when the Master Boot Record/Partition Table is first created and stored. The Disk Identifier is stored at byte offset 1B8 (hex) through 1BB (hex) in the MBR disk sector. Windows Vista uses the Disk Signature to locate boot devices so changing it can prevent Vista from booting. Apart from being able to display it I am not sure if this is used by Linux.

Vendor ID

Every USB device has a Vendor ID (VID), Product ID (PID) and optionally a serial number. The Vendor ID is intended to identify the manufacturer of a product: all USB devices from the same manufacturer should have the same VID irrespective of what they are so a mouse, a phone, a disk drive, etc. if made from the manufacturer should be the same.

Each manufacturer is supposed to assign a unique PID to each product they make so the VID:PID combination should uniquely identify a particular product (make and model) some manufacturers choose to assign unique serial numbers to their products but others don't so you can not use the VID and PID to uniquely identify a device because if you ever buy another one of the same make and model It will be the same.  In addition some manufacturers have been known to use the same PID for different similar models.  The output of the lsusb command contains the VID:PID combination.

UUID

A UUID (Universally Unique Identifier) is a 128-bit number. UUIDs are used to identify many different things including some filesystem partitions. Where the UUID is stored for a filesystem depends on the filesystem. Linux ext2/ext3 and Windows NTFS identify filesystems by UUID. UUIDs are generated randomly using either the current time or a random number generator. The UUID is generated and stored when the filesystem is formatted and then does not usually change.

When you copy a partition or disk as raw binary data (for example, with "dd") the Disk Identifier or UUID is also copied. That can result in two disks or two partitions with the same identifier. There are utilities to change the UUID to a new (random) number. There are also utilities to change the Disk Identifier in the Master Boot Record.

The advantage to a UUID is that no matter where you move a filesystem, an operating system can find that particular filesystem. For filesystems that have no UUID the Disk Identifier can at least be used to locate the disk drive.

While it is possible to change the UUID in normal use this its unlikely to change.

Linux can use device names for partitions when UUIDs are not available. I would recommend using the UUID to identify your mount point.

To set the Mount point there are two options for drives that are permanently connected see the FSTAB -Community Documentation  or for drives that are not always available if you are happy for it to appear as a subdirectory of /media/ but with a known name see RenameUSBDrive

A USB Drive can be formatted in lots of different formats. Many are formatted FAT by default because its a format that can be read by almost anything. But if this drive is only used on Linux it may be preferable to reformat it ext3 or ext4 see this question How to format a USB or external drive?


Have you tried installing the nvidia drivers through the terminal?

sudo apt-get update

sudo apt-get install nvidia-364


How to change color AND width of non overlay scrollbars in Ubuntu 12.04

I'm assuming you are referring to the overlay scrollbars because you mention Unity.
I don't know how to change the width but you can certainly change the color. If the color is distinct enough, I feel the width isn't that much of a problem because on hover it becomes decently wide.

You need to look in your theme's folder for files called gtkrc (in the gtk-2.0 folder) and gtk-widgets.css (in the gtk-3.0 folder). Open these files with a text editor. You may need to use gksudo gedit instead of just gedit if your theme is in /usr/share/themes and not in ~/.themes.
Then, search for overlay scrollbars or overlay-scrollbar or something similar and play with the colors specified in those sections. You can even specify your own color in hex code.

Obviously, you can set different colors in the two files if you so choose.

To visualize the changes you may need to switch to another theme and back after you've made and saved the changes to these files.

The changes you make in /usr/share/themes will be system-wide and changes in ~/.themes will be user-specific.

This is what my overlay scrollbar looks like in PCManFM.

Edit: In case, one is using conventional scrollbars, then to increase the contrast between the slider and trough in gtk-3.0 apps such as gedit, one can edit the gtk-widgets.css file mentioned above. To do so, search for the section titled scrollbar (or something similar) and look for the lines that have something like this:

.scrollbar.slider,
.scrollbar.slider:hover,
.scrollbar.button,
.scrollbar.slider.vertical,
.scrollbar.slider.vertical:hover,
.scrollbar.button.vertical {
    background-image: -gtk-gradient (linear, left top, right top,
                                 from (shade (@bg_color, 1.08)),
                                 to (shade (@bg_color, 0.92)));
    border-style: solid;
    border-width: 1px;

In here, one can play with the values for the background-image by changing the shade. A higher value is brighter, a lower value is darker.

I prefer to do something more simple: I change background-image to background-color and just have a color I like. So, for example, background-color: red; would probably give outstanding contrast.

My code looks like this:

.scrollbar.slider,
.scrollbar.button,
.scrollbar.slider.vertical,
.scrollbar.button.vertical {
    background-color: #003263; /*@theme_bg_color;*/
    /**/
    /**/

Obviously, a backup before editing is advisable and one can comment out stuff in the gtk-widgets.css file instead of deleting things by using /* and */.

(I can't get the formatting of block quotes to work while posting answers. If somebody would clean things up, I'd be grateful.)

One last edit (I hope):
Users of Chrome or Chromium may increase contrast by editing their gtk-2.0/apps/chromium.rc file if their theme provides it or by editing gtk-2.0/gtkrc if what is required is present there.
In both cases one should search for a section headed style "chrome-gtk-frame". In here, again, play with the shade value in this (or similar) line:

ChromeGtkFrame::scrollbar-slider-normal-color = shade (1.4, @panel_bg)

Or one can simply specific a color like this:

ChromeGtkFrame::scrollbar-slider-normal-color = "#003263"

or

ChromeGtkFrame::scrollbar-slider-normal-color = "blue"

(The quotes are required.)


Conky disappears when using ctrl+super+D

Open the configuration file in your home folder ~/.conkyrc and change own_window_type normal to own_window_type desktop

Though some have pointed out that parameters like override,dock or panel might work as well, the parameter desktop gives the nicest behaviour in most cases.


Write a file in the middle of a shell script

If you want lines to be indented in the generating script (for readability) but not indented in the generated sub.sh script, then you can do so with a here-document as follows:

change the << to <<-
indent with TAB characters not spaces

The terminating EOF may also be indented with a TAB if you prefer. From man bash:

   If the redirection operator is <<-, then all leading tab characters are
   stripped  from  input  lines  and  the line containing delimiter.  This
   allows here-documents within shell scripts to be indented in a  natural
   fashion.

So

cat > sub.sh <<- EOF
    #!/bin/bash
    #SBATCH -o %j.o
    #SBATCH -e %j.e
    #SBATCH -t 01-00:00:00
    mpirun -n 24 castep.mpi "$dir" > sub.sh
EOF

^^^^ these are tabs not spaces

(I also removed the unbalanced double quote - presumably left over from the original echo version - and instead double-quoted the $dir variable to prevent possible word-splitting.)


Dist-upgrade seems to have created an issue

I had the same problem after running sudo do-release-upgrade -d on a Ubuntu 16.04 cloned partition. The intent was to test for bugs in upgrade to 18.04.1 but the system stalled with message:
To continue please press [ENTER]
Inhibiting until Ctrl+C is pressed...

So I pressed Ctrl+C and it returned to command prompt.
Next I ran:
$ sudo apt update
Hit:1 http://security.ubuntu.com/ubuntu bionic-security InRelease
Hit:2 http://ca.archive.ubuntu.com/ubuntu bionic InRelease
Hit:3 http://ca.archive.ubuntu.com/ubuntu bionic-updates InRelease
Hit:4 http://ca.archive.ubuntu.com/ubuntu bionic-backports InRelease

(appstreamcli:15814): GLib-CRITICAL **: g_strchug: assertion 'string != NULL' failed

(appstreamcli:15814): GLib-CRITICAL **: g_strchomp: assertion 'string != NULL' failed

(appstreamcli:15814): GLib-CRITICAL **: g_strchug: assertion 'string != NULL' failed

(appstreamcli:15814): GLib-CRITICAL **: g_strchomp: assertion 'string != NULL' failed
AppStream cache update completed, but some metadata was ignored due to errors.
Reading package lists... Done
Building dependency tree
Reading state information... Done
1675 packages can be upgraded. Run 'apt list --upgradable' to see them.

Based on comments above plus this answer: Hit Ctrl+c during do-release-upgrade. Did I break it? I used:
sudo sed -i -e 's/bionic/xenial/g' /etc/apt/sources.list

Now sudo apt update completes normally.
Problems with upgrade
Now when I run do-release-upgrade -d and pay close attention I notice these lines in the middle:
Get:57 http://ca.archive.ubuntu.com/ubuntu bionic-backports/universe DEP-11 64x64 Icons [1,789 B]
Fetched 44.8 MB in 6s (4,884 kB/s)

(appstreamcli:30117): GLib-CRITICAL **: g_strchug: assertion 'string != NULL' failed

(appstreamcli:30117): GLib-CRITICAL **: g_strchomp: assertion 'string != NULL' failed

(appstreamcli:30117): GLib-CRITICAL **: g_strchug: assertion 'string != NULL' failed

(appstreamcli:30117): GLib-CRITICAL **: g_strchomp: assertion 'string != NULL' failed
AppStream cache update completed, but some metadata was ignored due to errors.

Checking package manager
Reading package lists... Done

I abort the upgrade by answering N to prompt.
A quick search leads to this Question & Answer: E: Problem executing scripts APT Update::Post-Invoke-Success error during apt-get update
I can verify the same situation using:
$ sudo apt update
Hit:1 http://security.ubuntu.com/ubuntu xenial-security InRelease
Hit:2 http://ca.archive.ubuntu.com/ubuntu xenial InRelease
Hit:3 http://ca.archive.ubuntu.com/ubuntu xenial-updates InRelease
Hit:4 http://ca.archive.ubuntu.com/ubuntu xenial-backports InRelease
AppStream cache update completed, but some metadata was ignored due to errors.
Reading package lists... Done
Building dependency tree
Reading state information... Done
All packages are up to date.

The recommended solution in the link is to use:
sudo apt-get purge libappstream3

Running this the meta error is now gone:
$ sudo apt update
Hit:1 http://security.ubuntu.com/ubuntu xenial-security InRelease
Hit:2 http://ca.archive.ubuntu.com/ubuntu xenial InRelease
Hit:3 http://ca.archive.ubuntu.com/ubuntu xenial-updates InRelease
Hit:4 http://ca.archive.ubuntu.com/ubuntu xenial-backports InRelease
Reading package lists... Done
Building dependency tree
Reading state information... Done
All packages are up to date.

Next step will be to run sudo do-release-upgrade -d a third time and cross my fingers.
Misleading message during upgrade
Another user had similar problem: Ubuntu upgrade from 16.04 to 18.04 is taking too long
Turns out the two line message comes out at the same time:
To continue please press [ENTER]
Inhibiting until Ctrl+C is pressed...

You think the upgrade is inhibited until you press Ctrl+C but what it really means is the upgrade doesn't start until you press Enter.
sigh


Startup Disk Creator seems to support any Debian-based distro, including Debian and Mint.


Making external drive accessible from Ubuntu

Aha! You have it formatted (check) in a format the Humax can read (check) and now need to be able to write to it. Well, then, mount the drive in Ubuntu then from a terminal window on your Ubuntu box, please run

  sudo chmod -R 646 /path/to/mountpoint

where /path/to/mountpoint is the path to the drive, such as /dev/sdb

If you are uncertain as to its name, run

  sudo lshw -C disk


How to use the keyboard in gthumb image viewer?

There are still some key combinations/shortcut-keys available. This is a nice list, but in gThumb 3.0.1 (Ubuntu 12.04) a lot of the shortcut-keys don't work (anymore). But I can still use:
Space or Page down View the next image.
Backspace or Page up View the previous image.
+ Zoom in
- Zoom out
1 or z Actual size
x Zoom to fit (scales down only, does not magnify)
Shiftx Zoom to fit (scale down or magnify, as required)
F11 or f Fullscreen
Nevertheless it would be great if there would be more flexibility and the possible to change keyboard shortcuts. There are bug reports on Gitlab and Launchpad for this, please subscribe, comment and contribute if possible.
Not sure what you mean with preview box, the thumbnail pane (F8 to close and open it) still works and you can switch it to the side if that is more convenient for you.

But pressing delete does not work anymore, so no move of viewed picture to the trash, what is really annoying. Daniel filed a bug, please sign as well that it affects you.
UPDATE 15 Aug 2012: Fix is released and pressing delete will move the picture to the trash again.


The file is called

/etc/init.d/mysql

not mysqld.

You can use also

sudo service mysql restart

Check afterwards if MySQL is running: you can use e.g. top or htop or run ps -aux|grep mysql.


Boot-repair can't complete a repair under Ubuntu Gnome 14.04

It's not

sudo apt-get install -y --force-yes grub-pc linux

It's

sudo apt-get install -y --force-yes grub-pc

There is no such package named linux.


launch Qt Creator without Ubuntu SDK add-ons

You can disable plugins at start of qtcreator.

qtcreator -noload <plugin>

Where <plugin> is the name of the ubuntu sdk plugin in your system.


try sudo apt-get install libmono-wcf3.0-cil (in case libmono-wcf3.0-cil  depends on some other package install that one too). if it is successful, then your package can be installed by sudo apt-get install manager-accounting.(i solved a similar problem like this, don't know whether applicable here).


Is my sound card dead? Ubuntu/Xubuntu no audio

There could be so many reasons behind this that the best advice for you is to follow a sound troubleshooting guide like this one. Whenever I have problems I use it. It has saved me many times!


Assuming that your mail server accepts the TCP connection (instead of telnet waiting for the connection to be dropped and you just typing away:)), try the following (you have errors in your SMTP conversation):

telnet localhost 25
helo carlo.ru
mail from:<test@localhost>
rcpt to:<test@localhost>
data
test
.
exit

It's helo or ehlo not hello and it's also rcpt to instead of rep.


Can I download & Install the wallpapers from 12.10 on 12.04.1?


How to prevent alt-f1 from selecting Dash

You'll need the CompizConfig Settings Manager (which you can install via the Software Center).

Once open, click on Ubuntu Unity Plugin (in the Desktop section). Under the Behavior tab, you'll see Key to put keyboard-focus on launcher. Simply change the keybinding there.

Note that in later versions of the Unity plugin, the tabs in that plugin have changed (as the comment below by Carlton mentions). The Key to put keyboard-focus on launcher stting is now under the Launcher tab.


in the ccsm search for unity plugin and enable it.. it should be on top.


I can confirm that Ubuntu 20.10 x64 (and I'm guessing x32 as well) can be installed on an external SSD to be used natively with the Raspberry Pi 4. To write Ubuntu on an SSD, one should use the Raspberry Pi Imager from here.


You don't have a partition table on the SD card, so if in the unusual case that you put a filesystem on the unpartitioned device, you need the loop option, -oloop in the mount command.  If you have nothing on the card and you want to use it normally, add a partition to it with fdisk, then make a filesystem on it with mkfs.vfat.  If you actually have data on the card, you should not make a new filessytem on it, but try a recovery tool like testdisk.
  Learning to use a new tool, start with the "man" pages,(manual),

man fdisk


Where to get the drivers for AVerMedia AVerTV Digi Volar X A815?

It is perfectly supported in Linux, even the IR remote.  Its very powerful at bad conditions but not stable for 24x7 use.

First thing, you need to copy the following firmware dvb-usb-af9015.fw in your /lib/firmware/ directory.  This is now part of the dvb-v4l dev tree and if you are compiling from mercurial snapshots this will be done for you.

The driver is supported in the latest v4l-dvb, so you have to download them first. Either getting or using mercury See the How to Obtain, Build and Install V4L-DVB Device Drivers for all the details.

The latest development version of the driver gives support to the RM-FP remote control. But there are other remote control versions bundled with the device. RM-KS is one of those.

Download and compile the drivers, and then use the option remote=5 when dvb-usb-af9015 module is loaded. This is made adding (as root) a file called, for example, dvb, in the directory /etc/modprobe.d/ with the line

options dvb_usb_af9015 remote=5

For LIRC Configuration, first step is to identify the file device associated with our dvb-t device. This is made by command:

cat /proc/bus/input/devices | grep -n10 a815

This command will display an output like this:

I: Bus=0003 Vendor=07ca Product=a815 Version=0200
N: Name="IR-receiver inside an USB DVB receiver"
P: Phys=usb-0000:00:13.2-4/ir0
S: Sysfs=/class/input/input8
U: Uniq=
H: Handlers=kbd event8
B: EV=3
B: KEY=3c0110 10200000000000 0 8400 90c0300801 1e060000000000 ffc

The information that you need is the input device number that in this case is /class/input/input8 This means that the device associated with the IR is

/dev/input/event8

ATTENTION! The device number change from PC to other. So this is only an EXAMPLE. So we must modify the lirc configuration that is in /etc/sysconfig/lircd or /etc/lirc/hardware.conf (change from distribution to other) this parameters:

...
DRIVER="devinput"
...
DEVICE="/dev/input/event8"
...

Second step is to generate the codes list by lirc tools. ATTENTION! the files provided by lirc in folder /usr/share/lirc-remotes/avermedia/ not work every time so we need to generate a file manually. We need to stop lirc first by this command:

/etc/init.d/lircd stop

Now we can generate the /etc/lircd.conf with irrecord by this command:

irrecord -H dev/input -f -d /dev/input/eventX ~/lircd.conf
cp ~/lircd.conf /etc/

but first you must replace the X with the number of the device. In my case I have /dev/input/event8 so I put 8. Follow the instructions on screen for build the file. Press RETURN then old down any key of remote control for find GAP value. If the device chosen its right you can see a progressive dot displaying. We gap search is done we must put a name for the key and press ENTER and then the relative button on remote control. This for all key in the remote control. To end the procedure we con press ENTER.

Some distribution need the file in /etc/lirc/ so we can copy the file in this way:

cp /etc/lircd.conf /etc/lirc/

Finally we restart lirc with:

/etc/init.d/lircd restart

We can use the LIRC front-end irkick for settings the remote control keys or build manually the ~/.lircrc file.

Due to some problems with the HID devices, in some machines the IR reception is buggy, to solve this, you can create the file /etc/modprobe.d/usbhid containing:

options usbhid quirks=0x07ca:0xa815:0x04

and then execute

sudo update-initramfs -u

and reboot. The problem should be solved that way.

Once compiled you can try this: Testing_your_DVB_device.  Kaffeine seems the easiest/fastest way to check if it works.

Source:LinuxTV


What does the dot (.) in a command mean?

The . in this context is a deprecated form of : and is a separator between the new owner and group.

From info chown:

   Some older scripts may still use ‘.’ in place of the ‘:’ separator.
POSIX 1003.1-2001 (*note Standards conformance::) does not require
support for that, but for backward compatibility GNU ‘chown’ supports
‘.’ so long as no ambiguity results.  New scripts should avoid the use
of ‘.’ because it is not portable, and because it has undesirable
results if the entire OWNER‘.’GROUP happens to identify a user whose
name contains ‘.’.

So in this context it's the same as chown root: /swap, which in turn means

OWNER:
     If a colon but no group name follows OWNER, that user is made the
     owner of the files and the group of the files is changed to OWNER’s
     login group.

Since root's login group is root, it's equivalent to chown root:root /swap


This won't answer you question exactly, but I believe you would have to play around with the utilities referenced in here: http://hwraid.le-vert.net/wiki/LSIMegaRAIDSAS and here:https://raid.wiki.kernel.org/index.php/Hardware_Raid_Setup_using_MegaCli#Delete_Raid_Device_.28Virtual_Drive.29.


Follow these instructions:
http://www.pendrivelinux.com/restoring-your-usb-key-partition/

Alternatively, if you're in a Windows machine you can also use diskpart:

Launch diskpart through Run ( Win+R ) or cmd.exe, then enter the following, line by line:

list disk
select disk <insert disk number here>
clean
create partition primary
select part 1
format fs=ntfs label=<insert custom name here> quick
assign letter <insert custom single-letter here>


Install vmware workstation 11 from the terminal

just use

  curl --user name:password http://www.link_to_vmware_package.com/

or

  curl http://www.link_to_vmware_package.com/

if it doesn`t require login


Kernel tainted and attempted to kill init ubuntu 16.04.06

Lets first check your file system for errors.

For 17.10 or older...

boot to the GRUB menu
choose Advanced Options
choose Recovery mode
choose Root access
at the # prompt, type sudo fsck -f /
repeat the fsck command if there were errors
type reboot

For 18.04 or newer...

boot to a Ubuntu Live DVD/USB
open a terminal window
type sudo fdisk -l
identify the /dev/XXXX device name for your "Linux Filesystem"
type sudo fsck -f /dev/XXXX # replacing XXXX with the number you found earlier
repeat the fsck command if there were errors
type reboot

Looks like you've got an old BIOS.

Go to https://us.msi.com/Motherboard/support/Z97-PC-Mate.html and get the newer version, install it (if you can) and see if that solves the problem.

See https://us.msi.com/files/pdf/How_to_flash_the_BIOS.doc for BIOS update instructions.

Update #1:

A Ubuntu reinstall was required to fix the problem.


apt-get failing with 2 interfaces in /etc/network/interfaces

Just remove the gateway from eth1 config:

auto eth1
iface eth1 inet static
  address 192.168.56.105
  netmask 255.255.255.0


SSH'ing to my machine attaches an existing screen session and detaching it ends my SSH session

Original Answer
It seems that your byobu installation has probably edited one of your login script files. You should search these, namely

~/.bashrc
~/.profile
Possibly the system-wide files too

for byobu or screen - you can use grep or just open up the file.
E.g. Open ~/.bashrc and search for byobu, namely something like
if [ $SSH_TTY ] && [ ! $WINDOW ]; then
    SCREENLIST=`screen -ls | grep 'Attached'`
    if [ $? -eq "0" ]; then
        echo -e "Screen is already running and attached:\n ${SCREENLIST}"
    else
        type -P byobu &>/dev/null && byobu -U -R || screen -U -R
    fi
fi

Comment out this section to restore normal ssh behaviour.
See here for more information about this automatic reattaching behaviour.
This Is What Worked (see comments below)
In ~/.profile, comment out  _byobu_sourced=1 . /usr/bin/byobu-launch
And if you're trying to launch an X11 Firefox session, just ssh -X <hostname> firefox (you may need to add the -no-remote flag).


Ubuntu 20.04 with LVM will not boot but enter GRUB console

If you installed with encryption, that encryption would be pointless if you can get to the login screen without decryption.
To get your system booted to the point where login is operating, a lot of your file-system would need to be visible (meaning unencrypted).
An encrypted $HOME directory allows for you to get to the login screen (where only user files are encrypted, not system files allowing the code before login to be run), but it reads like you opted for full disk encryption which requires the key to unlock before you can boot.
My current desktop has encrypted $HOME, so anyone can turn it on and get to the login/greeter screen (they just can't read my files within my $USER directory until logging in). However for any laptop or device that isn't bound to a desk, I use full-disk encryption.


How to assign static IP to KVM VM after bridging?

Editors there is a different question, but fundamentally the same problem I answered here. New to this so not sure if/how to merge - Ping to LXC container

In addition to the bridge, you need ensure you have a dedicated virtual network card on the Linux Container which will then be assigned the IP address on your hosts machine's network.

Below are the core instructions, but detailed steps and background come from this Bonsai Framework article.

  Create a Permanent macvlan on the Host

  Add to the bottom of the /etc/network/interfaces file of the host,

# Creates a macvlan interface called macvlan0 without an IP address
iface mvlan0 inet manual
   pre-up ip link add mvlan0 link eth0 address 8a:38:2a:cc:d7:aa type macvlan mode bridge
   post-down ip link del macvlan0
auto mvlan0

Reboot your system to have the change take effect. You will notice a mvlan0 now when viewing your network devices with ifconfig -a.

Connect Container to macvlan on Host by modifying the config file located in /var/lib/lxc/[container]/config.

  The entries to add for your new network card,

# macvlan for external IP
lxc.network.type = macvlan
lxc.network.macvlan.mode = bridge
lxc.network.flags = up
lxc.network.link = mvlan0
lxc.network.hwaddr = 00:16:3e:8d:4f:51
lxc.network.name = eth0

For the hwaddr, generate a unique locally administered unicast MAC Address via a free website like helion.org.

Finally, adjust the interfaces file within the container to bind via static or if you prefer use dynamic.

In my case, I adjust my home router so that 192.168.0.1 to 192.168.0.20 are not dynamically assigned and use static in my LXC.

So I modify my containers interfaces file as follows,

auto eth0
iface eth0 inet static
address 192.168.0.12
gateway 192.168.0.1
netmask 255.255.255.0

auto eth1
iface eth1 inet dhcp

Restart your Linux container.


Why is there a lack of Backports of Optional 10.10 or later Packages in repos?

So, the short answer really isn't short at all. From the kernel perspective, there shouldn't be many issues using gcc-4.5 on a machine that was compiled with gcc-4.4. The exception to that rule would be if you are needing to do any DKMS compiles as the compiler must be the same.

If you don't need to do any dkms compiles, then it may be possible for you to use 4.5 on your machine, but if I were doing this myself, I would try to run a VM with 10.10 to get the advantage of that compiler, but that is without knowing if you can do virtualization on your current machine.

Edit: After speaking with the Foundations team, it is a lack of time and resources keeping the backports from happening.


How do I add a launcher for .sh applications?

PhpStorm now has a feature to create a launcher for you. It's available under:

Tools -> Create Desktop Entry...

This will add PhpStorm to the system menu for the current user or for all users. The created launcher is also compatible with Gnome Shell.


Ethernet not working after update 14.04 (64 bit)

open  /etc/network/interfaces using

sudo vi  /etc/network/interfaces

add line

auto eth0
iface eth0 inet dhcp

then do

sudo ifdown eth0
sudo ifup eth0

you are saying sudo dhclient eth0 working so do above change it will search for DHCP when you start system also make sure you have proper proxy setting in your system .current ifconfig output shows your system getting IP from DHCP.

EDIT: For  device not managed you have to open /etc/NetworkManager/NetworkManager.conf using command :

sudo vi /etc/NetworkManager/NetworkManager.conf

and change the line managed=false to managed=true and restart NetworkManager

sudo service network-manager restart

For more info related this problem you can take help from Askubuntu another question network manager says “device not managed”


Can see wifi connections, but cannot connect

First check your wireless interface with the following command and Verify that your network device ("wlan0"?) is working & your wireless network is detected:

iwconfig

iwlist scan

Use the following command to change the channel:

iwconfig wlan0 channel #

where wlan0 is the name of your interface and # is the channel number you wish to switch to. After you have run that command, the channel is set to the new number of your choosing.

change 802.11bgn to 802.11bg.

iwconfig wlan0 modu 11g

Change wpa encryption to CCMP

wpa-pairwise CCMP

Hope this helps!


Software Updater screen not Showing all details

It has already been reported.  You can see the status here:

https://bugs.launchpad.net/ubuntu/+source/update-manager/+bug/1623856


Typically, you don't directly login to a node managed by MaaS. Instead, a tool like Juju (or some other program) connects to the MaaS interface and manages the machine for you, including worrying about what the login should be.

However, I believe if you go into the settings page in MaaS, you can set a SSH key for the machines to trust. You could tell it to trust the SSH key on your machine. You could then use that (along with the IP address listed for the node in the MaaS interface) to ssh to ubuntu@ip_address_of_node and login that way.


What are some to-do/reminder + calender apps in Ubuntu that pin to the menu bar indicators?

You can try installing Google Calendar Desktop application

sudo add-apt-repository ppa:atareao/atareao
sudo apt-get update
sudo apt-get install calendar-indicator

Once installed, go to top left corner and click on

and then search for Calendar-indicator and once you are able to see the ICON you can drag to vertical sidebar like this-->

And now you can start making use of it. One can easily sync with the google calendar also to access the schedules anywhere(laptop or smart phone etc...).

This works fine on my Ubuntu Desktop 14.04 LTS.


Copy&pasting the root partition, fstab is ignored

From investigations in a virtual machine where I believe I managed to reproduce your case, you are only a few steps away from achieving your goal.  This fix assumes your machine boots to a state equivalent to that shown in your gparted picture above: you have booted from sda6 and sda1 is not mounted but shows a mount point of / and the boot flag. It also assumes that an fstab exists on sda1 that shows sda1 mounted at /.

From this point:

In gparted, select the sda1 partition and from the right-click
menu, select "Mount at /"
Exit gparted, open a terminal, and type sudo update-grub.
Reboot your computer.

This should get you to your desired end state of booting off sda1 and having sda6 mounted at a different point than /.


I figured it out, it turns out that the DSI1 (the second DSI interface) overlapped with some other interface (I think CSI0) because it wasn't configured correctly. If you want to enable both, you have to disable one of the camera interfaces. In this case you can just disable DSI1 and more useful errors start showing up.


How do I install Nvidia Optimus in 14.04?

I just installed nvidia-prime via terminal:

sudo apt-get install nvidia-prime

A reboot and everything worked fine. I recommend to install Prime Indicator for a fast switch:

sudo add-apt-repository ppa:nilarimogard/webupd8
sudo apt-get update
sudo apt-get install prime-indicator

Log out and log in and voila.


Is it possible to check internet speed using the ping command?

To my own surprise this acually seems to be possible: see here

However I would only recommand to use this methode in a LAN network. If you want to check your internet speed use speedtest
You can install it via apt:

apt install speedtest-cli

Then just run the command

speedtest

and it will measure you internet speed.


How do i switch from ubuntu back to chrome OS?

When booting press tab to enter to the GRUB menu and there you can enter back to your chrome OS.

Or edit /etc/default/grub

change the GRUB_TIMEOUT value to -1

This will ensure that you enter GRUB always to choose which os you want to boot
then do the command

sudo apt-get update-grub


Connect two computers with SSH in a home LAN

ssh within a home Local Area Network (LAN)
I assume there are two users each with their own computers running Ubuntu.

user1 uses comp1 and
user2 uses comp2.

The goal is for user1 to remotely access comp2 using user2's account in comp2.
Note: If user1 has an account in comp2 and user1 wishes to access her account in comp2 from comp1 then she she does not have to specify the username in the ssh command. ssh comp2.local will work.
Setup ssh server in comp2
For this you will need to physically go to comp2 and login to it using an account with administration privileges. I assume that is, user2 account.
Install the ssh server
Desktop Ubuntu does not come with any servers. To ssh into comp2 you will first need to install the openssh-server. Open a terminal in comp2 by pressing Ctrl+Alt+T and enter the following lines one at a time:
sudo apt update
sudo apt install openssh-server

You will be asked for user2's password. When you type the password the cursor will not move and it will seem like nothing is happening. This is normal. Hit Enter after typing the password. Then follow the instructions.
Once openssh-server is installed you will see a new options in Settings under sharing called "RemoteLogin" and it will be "On":

The standard Ubuntu desktop does not come with any firewalls installed. If you have a firewall installed then make sure it allows connections to port 22 from within the LAN. The instructions will depend on the specific firewall software.
Test ssh locally
Still at the terminal of comp2 test that ssh is working. Enter the command:
ssh 127.0.0.1

The 127.0.0.1 refers to the IP address of the computer you are using. In other words, you are trying to ssh from comp2 to comp2. If all goes well you will be asked if you are sure you want to connect and then for your password. Once you answer yes for being sure and enter the password for user2 you will see the terminal prompt change from user2@comp2$ to user2@127.0.0.1$. This shows that you have successfully sshed from comp2 to itself.
Note: Since the same user (user2) is ssh-ing in this case, you don't need to specify ssh user2@127.0.0.1 in the ssh command.
ssh from comp1
To ssh from comp1 to comp2 you can either use the computer name (hostname) or its IP address. To find the IP address of comp2 use the ifconfig command in the terminal of comp2. You will see an address like 192.168.x.y, where x can be 0 or 1 and y can be any number between 2 and 255.
Form a terminal in comp1 enter either:
ssh user2@comp2.local

or
ssh user2@192.168.x.y

Note: If you use the name of the computer then you must add .local at the end. If you use the local IP address, it may change from time to time if a fixed address is not assigned.
Security concerns

Router setup
Enable public key based authentication and disable password based authentication.
Install and configure a firewall

1. Router setup
Make sure port 22 is not forwarded to any computers in the home router. This will prevent anyone from outside the home LAN use ssh to connect to the home computers.
The instructions are router specific and beyond the scope of this answer as it has nothing to do with Ubuntu.
2. Enable public key based authentication and disable password based authentication
This is more secure way to use ssh. It uses a private-public key pair. The private key remains in the trusted computer from which the ssh connection is made. In this case comp1. The public key goes to comp2. Once the keys are in place, you will disable password based authentication in the ssh server in comp2. If you disable password based authentication without making sure the key based authentication is working, then ssh will not work, as there will be no way to authenticate the remote user.
First generate the private-public key pair in the user1@comp1. This will need to be done at each user and each local computer from where you ssh to another computer. In a terminal enter:
ssh-keygen -t ed25519

This is generate the newer and more secure key than RSA. If you want RSA type keys, then enter:
ssh-keygen -t rsa -b 4096

The process will prompt you for a passphrase. You can hit enter if you don't want one. If you do enter a passphrase, you will be asked for it every time you ssh from comp1 to comp2. If you use a passphrase it should not be same as the password used for normal login.
Next you will need to copy the public key from comp1 to comp2. In the terminal in comp1 enter:
ssh-copy-id user2@comp2.local

You will be asked to enter the login password of user2 in comp2. If you have other computers in the home LAN you want to ssh to from the user1@comp1 then you need not create a new key-pair. Copy the public key of user1@comp1 to the other user accounts in the other remote computers using the above command.
Once the public key is successfully copied to the user2 account of comp2 try to ssh again:
ssh user2@comp2.local

Now you should be able to get into comp2 without user2's password. At this point one can either use the password or the public key you generated to log in. You can test this by creating a new user (or with an existing second user) in comp1, such as user1a. At this stage user1@comp1 will be able to ssh to user2@comp2 without password using the public key. On the other hand user1a@comp1 will be able to ssh to user2@comp2 will need to use the password of user2.
The next step is to disable the password based authentication. You may want to do this locally in a terminal of comp2. Use the following command to edit /etc/ssh/sshd_config
sudo nano /etc/ssh/sshd_config
Then make sure it contains the following lines and they are uncommented:
PasswordAuthentication no
ChallengeResponseAuthentication no
UsePAM no

Note these lines may not be together. "Uncommented" means there is no # in front of each of these lines.
Use Ctrl+W to save the changes and Ctrl+X to exit the editor.
Finally, restart the ssh server with the new settings by the following command:
sudo systemctl restart ssh

Now user1@comp1 will still be able to ssh to user2@comp2 without password using the public key. On the other hand user1a@comp1 will get permission denied to ssh to user2@comp2.
3. Install and configure a firewall
There are many firewall software, and some of them are hard to configure. I suggest you install the "uncomplicated firewall" called ufw by the command:
sudo apt install ufw

To open the port 22 but only from within the home LAN use the command:
sudo ufw allow from 192.168.x.0/24 to any port 22

Note: replace x with either 0 or 1 based on your router setup.
This firewall setting in comp2 stops anyone from outside the home LAN use ssh to connect to comp2. However, it allows anyone (using any computer) within the home LAN try to ssh into comp2. If comp2 is removed from home and taken somewhere else and connected to another "similar" network, say by WiFi, all the computers in that network will be allowed to access port 22 of comp2 by this firewall setting. For this reason I recommend password based authentication to be disabled and private-public key based authentication be used in all computers running the ssh server.
Hope this helps


How to connect locahost with my outside Database

So , People tell me , it is possible easy to making....

I to let my File provess.php  on my Website , than Write on my Browser ,

https://myWebsite/provess.php

and....

Screeshot


Cannot write to mounted samba share via proftpd

Try to add file_mode=0777,dir_mode=0777 to your samba mount:

mount -t cifs //sambaVM/data/listing /resource01 -o guest,file_mode=0777,dir_mode=0777

Add username= and password= options instead guest if needed.

Check permissions on /resource01 before and after mounting samba share. They can vary.

Check your FTP configuration by writing to /resource01 without samba mounted.


Audio freezes for 8 seconds every minute or so when using microphone, every device

I would suggest installing the Hardware Enablement Stack kernel:

sudo apt-get install --install-recommends linux-generic-hwe-18.04 xserver-xorg-hwe-18.04

However, the fact that your problem seems to affect a variety of different hardware might mean there is no benefit from the more modern drivers.


ImportError: /usr/lib/x86_64-linux-gnu/libharfbuzz.so.0: undefined symbol: FT_Get_Var_Blend_Coordinates

By trial and error I finally managed to get it working. I just had to switch versions of few libraries in my Anaconda enviroment. Those libraries and their versions are:

Harfbuzz 0.9.39 (I think it could work for any version pre 1.4.1)
Glib 2.58.2
Pango 1.39.0

Here is enviroment file content for someone with this error.


The solution is not straightforward. It requires start of script at X login and waiting till the and of X session. Fortunately we have inotify and pid of gnome-session.

Variety process should already be killed properly at the time of script execution.

Install inotify-tools package.
Create or modify ~/.xprofile script and add to it following line

sh .xlogout &

Create ~/.xlogout with following content

FILE=/tmp/.ICE-unix/$PPID            # pid of parent = gnome-session
sleep 10s                            # wait for $FILE creation
inotifywait -qe delete_self $FILE    # wait for $FILE deletion = logout
# your code goes here                # = on_quit
# gsettings reset org.gnome.desktop.background picture-uri


To install Skype in Ubuntu 16.04, run these commands in terminal one by one:

sudo add-apt-repository "deb http://archive.canonical.com/ $(lsb_release -sc) partner"
sudo dpkg --add-architecture i386
sudo apt-get update
sudo apt-get install skype

NOTE: sudo dpkg --add-architecture i386 is only for 64-bit system and not for 32-bit system. Also, if you get an error of missing dependencies, run sudo apt-get -f install from terminal.

Open Skype from Unity Dash. Then agree to Skype terms of use and Skype privacy policy. Next, sign in with your Microsoft account or Skype name. Then you're ready to use Skype!

Helpful Links

How to install Skype on Ubuntu 16.04 LTS


to make system upgrades you need to type sudo apt-get update to get the information about new updates from your repository and to download and install the upgrades you need to type sudo apt-get upgrade .

If you want this in a single command you could just add && like this:

sudo apt-get update && sudo apt-get upgrade

you need to type in your root passwd to be able to install updates.


How to set default viewport on Compiz Desktop Wall?

One solution I thought about was to run a command 1-2 seconds after startup in order to change your current workspace to the wanted one.

This answer here explains it perfectly:

Is there a command to go a specific workspace?

This answer explains how to run a command on startup

How do I start applications automatically on login?

In the "Command" field, you will need to input

bash -c 'sleep 3; wmctrl -o X,Y'

where X,Y the coordinates that you have to take from the 1st answer I posted.


Can a modified Ubuntu flash drive installation be installed on another system?

Using remastersys :

http://www.geekconnection.org/remastersys/ubuntu.html

You can create live iso of your existing system. So install all the required packages on your Ubuntu and then take a iso using remastersys. Then using startup disk, you can create bootable usb from this iso.

Edit your /etc/apt/sources.list file and add the following line in the end of the file:

deb http://www.remastersys.com/ubuntu precise main

Then run the following command:

sudo apt-get update
sudo apt-get install remastersys
sudo apt-get install remastersys-gui
sudo apt-get install remastersys-gtk

To run the remastersys in GUI mode, type the following command:

sudo remastersys-gui


Evince animation only works in GNOME Xorg

I don't have an example to test it here, but it's known that certain applications, such as Eclipse IDE, don't work properly on Wayland yet. GTK+ is fine, but maybe some other piece of code still relies on Xorg calls.

It would be nice if you take the time to report this bug to them.
https://wiki.gnome.org/Apps/Evince/ReportingBugs

As a workaround, you may call the program as GDK_BACKEND=x11 evince (notice the small case x). As a convenience, you may copy the /usr/share/applications/evince.desktop file to ~/.local/share/applications/ and edit that file so the Exec line becomes Exec=bash -c "GDK_BACKEND=x11 evince %U".


The instructions @andrew-beerman posted are on the right track, though they aren't quite clear to me and seem  to recommend more than is necessary. I pieced together the answer from the above and a helpful post in the bug thread.

These are the steps I took to correct this:

Back up your my.cnf file in /etc/mysql and remove or rename it

sudo mv /etc/mysql/my.cnf /etc/mysql/my.cnf.bak

Remove the folder /etc/mysql/mysql.conf.d/ using

sudo rm -r /etc/mysql/mysql.conf.d/

Verify you don't have a my.cnf file stashed somewhere else (I did in my home dir!) or in /etc/alternatives/my.cnf use

sudo find / -name my.cnf

Backup and remove /etc/mysql/debian.cnf files (not sure if needed, but just in case)

sudo mv /etc/mysql/debian.cnf /etc/mysql/debian.cnf.bak
sudo apt purge mysql-server mysql-server-5.7 mysql-server-core-5.7
sudo apt install mysql-server

In case your syslog shows an error like "mysqld: Can't read dir of '/etc/mysql/conf.d/'" create a symbolic link:

sudo ln -s /etc/mysql/mysql.conf.d /etc/mysql/conf.d

Then the service should be able to start with sudo service mysql start.

That got it working!


Ubuntu 18.04 resolution flickers after changing to a custom resolution with xrandr

The closest I could get was creating a script and then executing it with a desktop launcher after each time I login:

#!/bin/bash
xrandr --newmode "1280x720_60.00"   74.50  1280 1344 1472 1664  720 723 728 748 -hsync +vsync
xrandr --addmode VGA1 "1280x720_60.00"
xrandr --output VGA1 --mode 1280x720_60.00 && killall -3 gnome-shell

Any other better solutions are welcomed


Virtualbox on Ubuntu Host: Access guests by hostname

I suggest you use Multicast DNS to fix this.

Ubuntu is using this by default via Avahi.

The Windows host needs an Avahi-client for it to discover other Avahi-services. If your host already uses some Apple software this is probably already there via a service called Bonjour. However, if this is not already installed then a small version of Bonjour is available for download here: Bonjour Print Services. After installation you should be able to access your guest via .local.

Note: The mDNS system seem to use the .local postfix by default. So, if your hostname is "dev.myapp.com", then the actual hostname will be "dev.myapp.com.local".

Copied from my own answer at superuser.com.


Just disconnect, wait for a minute, and then just reconnect. I know it's annoying, but it works for me. Other than that, you may need patience and wait for Ubuntu to find a stability patch for that. This type of situation happens more often to me after i use Win8.1, and then switch to Ubuntu.


check the swap partition amount using disk utility.
I recently read through a lot info regarding partition set up.
I0 recall reading that if using a laptop or any form of Hibernation,
it is recommended that you set the "swap" partition to X2 your ram.
example: 4gb(4096MB) ram swap should be set to 8gb(8192MB)

-QUOTE from this site-
"In short: If you hibernate, allow your RAM size plus 1 GB (for instance, if you persist with buying 8 gigs of RAM, have a 9 gig swap partition). If you don't hibernate, don't bother with swap. You can always change your mind later and add it if you start doing high-end scientific analysis. "


What is the difference between Ubuntu and its derivatives?

The main two differences between Ubuntu and its derivatives are the backing and the default installed packages. For all official derivatives, you can convert between variants by installing certain packages.
Here is a small list:
Ubuntu
Ubuntu comes with the Unity desktop environment. The underlying Unity platform is still GNOME, but instead of using the GNOME Shell interface, Unity uses the Unity shell.
Ubuntu and Unity are commercially backed and supported by Canonical.
To convert an installation into regular Ubuntu, install ubuntu-desktop .
Kubuntu
This is the KDE flavor of the typical Ubuntu (which is GNOME driven). The primary difference is that Kubuntu comes with KDE as the default Desktop Environment, as opposed to GNOME with the Unity shell.
Kubuntu is sponsored by Blue Systems. Canonical stopped backing it in 2012, but it is still an officially recognized Ubuntu variant, which means that it gets build machines, test machines, CD image distribution servers, etc. dedicated to it.
To convert an installation into Kubuntu, install kubuntu-desktop .
Ubuntu GNOME
Ubuntu GNOME aims to have a mostly pure GNOME desktop installed by default.
Ubuntu GNOME is community-driven. It was originally called Ubuntu GNOME Remix; it was renamed to Ubuntu GNOME when it became officially recognized. Ubuntu GNOME is very new: its first release as an official derivative was 13.04 Raring Ringtail, which as of 6/9/13 is the current release.
To convert an installation into Ubuntu GNOME, install ubuntu-gnome-desktop .
Xubuntu
This is a lighter weight, highly efficient and optimized flavor of Ubuntu designed to run on older computers. It uses Xfce which is a proven faster Desktop Environment than both KDE and GNOME. This is a typically simpler slim interface.
Xubuntu is community-driven and operates under a Strategy Document. It is also officially recognized by Canonical (see Kubuntu for what that means).
To convert an installation into Xubuntu, install xubuntu-desktop .
Ubuntu Server
Ubuntu Server is optimized for use as a server. It does not come with X.Org, and as such does not use any graphical environment like a desktop environment or a window manager. Instead, it comes only with a CLI environment.
Ubuntu Server is commercially backed and supported by Canonical.
Mythbuntu
The counterpart to Xubuntu - Mythbuntu is designed to be an entertainment powerhouse. Focused around being a Media Center it includes many drivers and setups for TV Tuners, TV Out cards, and has a Media Center application (MythTV) integrated into the Desktop Environment to facilitate the entertainment powerhouse it advertises.
Mythbuntu is an officially recognized Ubuntu variant.
To convert an installation into Mythbuntu, install mythbuntu-desktop .
Lubuntu
Lubuntu takes the aims of Xubuntu and pushes the Desktop Environment to an even more bare bones lightweight variant:

LXDE (Lightweight X11 Desktop Environment) in releases up to 18.04, and
LXQt in releases after that.
Both are very efficient (LXDE used GTK2, it was being ported to GTK3 where it was deemed to heavy, so the devs ported it to Qt5, they then joined the Razor-Qt team forming the newer LXQt project).  It's a more efficient (the lightest official flavor out of the box), power saving, fast, lightweight Desktop Manager than XFCE (though if using GTK3 apps some of its lightness will be lost).

Lubuntu is community-driven. It is officially recognized as a variant by Canonical.
To convert an installation into Lubuntu, install lubuntu-desktop
My Opinion
I've used the first three before and I believe all have some backing from Canonical (or other corporate backing) while Lubuntu is still relatively new and community driven. Though if you have a very old/slow computer it certainly might be what you're looking for.

Figured I'd add the other flavors of Ubuntu I knew where out there
In addition to the above listed there is also:
Edubuntu
This flavor is designed with Educational intent. Runs very close to the vanilla Ubuntu release though it comes with many additional applications that are best suited for an Educational environment. It also is configured and stylized with kids in mind.
Edubuntu is an officially recognized variant.
Ubuntu Studio
This flavor is geared towards those who deal with multimedia (Video, Audio, Graphics, Design) on a daily basis. Comes bundled with many applications, codecs, and drivers required to facilitate those activities.
Ubuntu Studio is an officially recognized variant.
Ubuntu CE
Ubuntu CE (Ubuntu Christian Edition) is Ubuntu designed for Christians who wish to maintain an "Christianly" lifestyle. This comes bundled with a lot of religious software and security tools to help protect moral religious obligations.
Ubuntu CE is an unofficial derivative.
Nubuntu
This project is idle, but it's intent was to bring stronger hardened security to the stock Ubuntu installation. It targets security practitioners like penetration testers.
Nubuntu is an unofficial derivative.
Fluxbuntu
Fluxbuntu does not come with a desktop environment like GNOME or KDE. Instead, it only comes with a window manager called Fluxbox.
Fluxbuntu is community-driven. It is an unofficial variant.