Cannot increase open file limit beyond 999999 on 14.04+

I know it's 10 months late, but you've set the hard limit twice for all users.  Change the second line to be a soft ulimit.

* hard nofile 999999
* soft nofile 999999
root hard nofile 999999
root soft nofile 999999

After doing this you should see:

$ ulimit -n
999999
$

Your file should have always worked for root as the limits were correctly defined.

Furthermore you can't use -1, infinity, unlimited or the like, you must use a literal value.  The max supported value for this is defined in the kernel and is exposed in /proc/sys/fs/nr_open.  In my centos 7 & debian strech environments I get the same value:

$ cat /proc/sys/fs/nr_open
1048576
$

You also have to start a new session for the limits to update.


How do I submit feedback on the ubuntu font?

If you are reporting a bug or problem with the font, you should file it in Launchpad. Otherwise, you could ask a question on this page.


Bash script to check if mdadm is installed if not install it

From the wiki I got this

  If your system has RAID support, you should have a file called
  /proc/mdstat. Remember it, that file is your friend. If you do not
  have that file, maybe your kernel does not have RAID support.

Issue this command and see the result:

cat /proc/mdstat

It should tell you that you have the right RAID personality (eg. RAID mode) registered, and that no RAID devices are currently active.


How to empty the Active Block list in SelfControl?

After much searching, here's how I solved the problem.

sudo -H gedit /usr/share/perl5/SelfControl/UI.pm

Place the cursor after

$list->set_data_array($self->{config}->{hosts});
$list->get_selection->set_mode('multiple');`

Add this code:

# we need the following line otherwise the list is too small
$list->set_size_request(350,500);

  my @columns = $list->get_columns;
  my $cnum = scalar(@columns);
  my $c;
  foreach $c (@columns) {
$c->set_resizable(TRUE);
  }

  my $rows = $self->{config}->{hosts};
  my $rnum = scalar(@$rows);

  if ($rnum > 10){ $rnum = 10; }
  if ($rnum < 2){ $rnum = 2; }

  $list->set_size_request (175 * $cnum, 28 * $rnum);

Save and close.

Try launching the app and see if it works.


Ubuntu Budgie 17.10 layout switcher shortcut does not rotate

On Ubuntu Budgie, the switching layout shortcut Super+Space should work the same as what you are used to. However there seems to be a
Conflicting dconf key
The default dconf value for /desktop/ibus/general/hotkey/triggers Is similar to the layout- switch shortcut, which causes your issue.
Fix
To fix, run in a terminal window:
dconf write /desktop/ibus/general/hotkey/triggers "@as []"

and it should work as expected again.
Note
The issue will be fixed soon in Budgie with a gsettings override.

Additional information
Not directly what you asked for, but since you are using 17.10 and using multiple layouts, it might be useful to install the Keyboard Auto Switch, which automatically changes the layout, depending on the application:

In UB 17.10, activate backports in Budgie Welcome, update and install the applet. In 18.04, it will be available by default in Budgie Welcome.


60-latin.conf not a directory error in Ubuntu 16.04

I know it's an old question but I just stumbled on the same issue on my Debian Buster Rasperry pi OS (Linux raspberrypi 4.19.118-v7+) and the solution might be helpful for others:
For some reason, the symlinks in /etc/fonts/conf.d were not properly configured on my system despite being available. I created the following symlink to fix it:
cd /etc/fonts/conf.d
sudo ln -s /usr/share/fontconfig/conf.avail/60-latin.conf


Supported Graphics Card for Alienware 17

I know this is late but hopefully it will help others if not yourself. Yes, the R9 M290X is a rebranded HD8970M [1]. It shares the Pitcairn core of its desktop brother, the venerable Radeon HD 7870 [1], and so we can look at that chip to determine the support of the this mobile variant.

According to this benchmark [2], the support of this series is already acceptable but also considerably improved over the last few months. The performance of the 7870 is still behind the older 6870, so it stands to reason that because the hardware is better there is room for more optimization in the future. Either way, since you are most likely going to game under Windows, it is certainly good enough for regular desktop use like video acceleration or compositing.

The only area I'm not certain of is the BIOS used in Alienware laptops and that could be an issue for installing Linux, but you definitely don't have to worry about the graphics card.

[1] http://www.notebookcheck.net/AMD-Radeon-HD-8970M.90656.0.html

[2] http://www.phoronix.com/scan.php?page=article&item=amd_radeon_12nov&num=4


How to reduce LCD brightness if intel_brightness is unistalled?

If you want to change the screen brightness in Ubuntu (I can’t change it using the keyboard shortcuts or the Ubuntu Power Management menu), open a terminal and execute the following:

sudo setpci -s 00:02.0 F4.B=xx

Where xx is the desired brightness in hex ranging from 0 (brightest) to FF (no brightness at all). I usually change it to E0 when working on battery.


mythbuntu 12 - lirc device doesn't appear to even exist

lirc isn't running because you are trying to start it as a regular user instead of root. That is why there are no lirc devices. irw needs to be run after lirc has been started, you will only get irw to show responses from the remote if lirc has been successfully started.

You need to start lirc as root, e.g.

sudo lircd start

Though I always use

sudo service lirc start


How to install compiz-plugin-extras and make it work correctly?

Try this please:
Compiz Experimental
It always work for me, i am on Ubuntu 14.04.


How best to install Ubuntu 14.04 LTS only to replace WIN 7 and Ubuntu 14.04 beta 2 dual boot ?

first boot the live ubuntu 14.04
then format the partation containing xubuntu and win7
then install the ubuntu 14.04 using manual partitioning method.


There is an alternative touchpad driver specifically crafted for "true" multitouch capable devices.

forked touchpad driver by bluedragonX

The link to the deb file download seems broken. But its available in the ubuntu universe repositories if you have them enabled under the name xserver-xorg-input-mtrack
Its quite discussed in the ubuntu forums

It allowed a resting finger when i tried it on my MacBook touchpad after some tweaking.

The Synaptics people seem to have been working on a fix as well. The bottom Edge feature in synclient is a result of this.

Its not working properly according to the launchpad bug  but It seems to have been fixed upstream and working in synaptics 1.7.6

Created a file under  /etc/X11/xorg.conf
with the following settings:

 Section "InputClass"
     MatchIsTouchpad "on"
     Identifier      "Touchpads"
     Driver          "mtrack"
     Option          "Sensitivity" "0.55"
     Option      "FingerHigh" "12"
     Option      "FingerLow" "1"
     Option          "IgnoreThumb" "true"
     Option          "IgnorePalm" "true"
     Option          "TapButton1" "0"
     Option          "TapButton2" "0"
     Option          "TapButton3" "0"
     Option          "TapButton4" "0"
     Option          "ClickFinger1" "1"
     Option          "ClickFinger2" "3"
     Option          "ClickFinger3" "3"
     Option          "ButtonMoveEmulate" "false"
     Option      "ButtonIntegrated" "true"
     Option          "ClickTime" "25"
     Option          "BottomEdge" "25"
     Option      "SwipeLeftButton" "8"
     Option      "SwipeRightButton" "9"
     Option      "SwipeUpButton" "0"
     Option      "SwipeDownButton" "0"
     Option      "ScrollDistance" "75"

 EndSection

Since there are many different touch pads you might need to tweak these settings initially.


use debsums to automatically check all installed packages

dpkg -l | egrep '^ii' | awk '{print $2}' | xargs sudo debsums | egrep -v 'OK'


Why can't I connect to xmlrpc.launchpad.net?

I had a very similar problem until recently.

First of all, if you are behind a proxy, you need to set https_proxy, NOT "http_proxy", because Launchpad uses https. If you have curl or wget, you can confirm your proxy setting is working by running something like this:

curl https://code.launchpad.net/

Secondly, there has been a long-standing bug about ssl certificates, which would prevent you from checking out projects through a proxy, even if correctly configured. This has been fixed in version 2.5.1. If you have an earlier version, even 2.5, you have to upgrade to 2.5.1 (the current stable).


How to remove the lock automatically after pressing ctrl+z?

No,

Because it is not possible for a program to catch SIGSTOP (sent by Ctrl+Z)

To quote the relevant parts of signal(7):

Signal     Value     Action   Comment
───────────────────────────────────────────
SIGSTOP   17,19,23    Stop    Stop process

The signals SIGKILL and SIGSTOP cannot be caught, blocked, or ignored.

Therefore, if you stop a progam with Ctrl+Z and close the terminal, it has no chance to perform cleanup (e.g.: removing lock files).
Ctrl+Z should not be used if you intend to cancel an operation, only use it if you intend to pause a program and resume it (or close it cleanly) later.

Thus, Ctrl+C should be used to terminate processes because a program can catch that signal and exit cleanly.

Although, in the case of apt-get, pressing Ctrl+C will leave the lock files behind, but terminate the process. This means that the lock files can be removed, but the package manager could be left in an inconsistent state, if you terminated it at a critical point.

There is really no safe option to terminate apt-get cleanly while it is installing/updating packages, but cancelling (Ctrl-C, then remove lock files) while it's downloading should be fine.


Backup and Restore Decrypted Partitions: Warning this a bit technical

I'm putting together some scripts that will automate most of this, but if you'd rather not wait, I've tested the steps below. Just be sure you know what you're doing. Don't blindly follow the commands I've written. Some of them may require substitutions specific to your system configuration. Once I've finished the scripts. I'll upload them to GitHub and edit this answer.

Unfortunately, you're not going to be able to recover or change the encryption password. You won't be able to create any new ones either without having one of the existing keys or passphrases. However, since you're logged into the system, you are in luck! Here's an option that technically doesn't require a full reinstallation. You say you're using whole-drive encryption, so I'm going to assume that you have two main partitions on your drive, a boot partition and a LUKS partition (if you're using EFI, you probably have a third partition for that). Then your decrypted LUKS partition is probably using LVM for any and all other decrypted partitions.
Your lsblk output probably looks something like this:

NAME                    MAJ:MIN RM  SIZE RO TYPE  MOUNTPOINT
sr0                      11:0    1 1024M  0 rom
sda                       8:0    0   16G  0 disk
├─sda2                    8:2    0  488M  0 part  /boot
├─sda3                    8:3    0   15G  0 part
│ └─sda3_crypt          253:0    0   15G  0 crypt
│   ├─ubuntu--vg-root   253:1    0 11.8G  0 lvm   /
│   └─ubuntu--vg-swap_1 253:2    0  3.3G  0 lvm   [SWAP]
└─sda1                    8:1    0  512M  0 part  /boot/efi

The only part of interest here is the sda disk.

How to make it happen, in general

Basically, the bit of the system that is encrypted is sda3, and it's encrypted with LUKS. The LUKS partition when unlocked contains an LVM physical volume, sda3_crypt, that hosts a single volume group named ubuntu--vg. This volume group then contains two LVM logical volumes, ubuntu--vg-root and ubuntu--vg-swap_1. If we can backup the LVM physical volume, sda3_crypt, then we can blow away the old LUKS partition on sda3, create a new one, and dump the LVM physical volume back on the new LUKS partition. There is one catch, though! All of the boot files in your boot partition, sda2 still reference the old LUKS partition that you destroyed. You need to update your /etc/crypttab file to point to the new LUKS partition that you created and rebuild your initram disks. Only after that is finished should you reboot your system.

Continue reading the next section for the actual steps to make this happen.

The Actual Step-by-Step Process

You're going to need a drive that you can afford to wipe, or at least a drive that has a partion of equal or greater size to that of sda3. The contents of said drive or partition will be completely wiped in this process. I'm going to do this example using the whole drive.
Run lsusb with your drive attached, and locate your external disk, sdb in my case.

sdb                       8:16   0   16G  0 disk
└─sdb1                    8:17   0   16G  0 part  /media/test/external-drive
sr0                      11:0    1 1024M  0 rom
sda                       8:0    0   16G  0 disk
├─sda2                    8:2    0  488M  0 part  /boot
├─sda3                    8:3    0   15G  0 part
│ └─sda3_crypt          253:0    0   15G  0 crypt
│   ├─ubuntu--vg-root   253:1    0 11.8G  0 lvm   /
│   └─ubuntu--vg-swap_1 253:2    0  3.3G  0 lvm   [SWAP]
└─sda1                    8:1    0  512M  0 part  /boot/efi

Unmount your external drive because we're going to be overwriting the content that's there. Replace /media/test/external-drive with the actual path to your drive in the following command.
sudo umount /media/test/external-drive
You need to clone the existing, decrypted LVM physical volume to your external device. In the following command, replace sdX with the device of your external hard drive. In my case, I would write ... of=/dev/sdb.... Also replace sda3_crypt with the name of your LUKS partition. This is going to take a good long while. It took me 35 mins in a test with just a 16GB LUKS partition.
sudo dd if=/dev/mapper/sda3_crypt of=/dev/sdX bs=4M status=progress
From here on out, be aware than any changes you make on your system may not be present when you restore. In fact, it's probably better that you don't use your computer while it does it's backup.
Once the backup has finished, reboot the computer using a live Ubuntu USB and select the option to try Ubuntu without installing.
Once the system is up, open a terminal and drop to root.
sudo -i
In this terminal, create a new LUKS partition on over the old one. In my example the LUKS partition is on sda3. Substitute the correct number from your system in place of sdaN in the command below.
cryptsetup luksFormat -c aes-xts-plain64 -s 512 -h sha512 /dev/sdaN
Follow the prompts and enter a passphrase that you hope never to forget.
Once that's done, you need to unlock the LUKS partition. Change the number to match your system in the next command, replacing the numeral 3 with the appropriate number for your device.
cryptsetup luksOpen /dev/sda3 sda3_crypt
Now your decrypted LUKS partition is open and ready for dumping the LVM physical volume back on (next command). Replace the X in sdX with the device of your external drive. Replace the 3 in sda3_crypt with the appropriate number of your partition.
dd if=/dev/sdX of=/dev/mapper/sda3_crypt
Again, you're going to have to wait for a really long time while everything is restored. Go find something else to do while you wait.
When restoration is finished, go ahead and remove the external drive and reboot. We want to make sure there are no LVM conflicts when we bring the system back up to finish updating the boot files on the internal drive. Once rebooted without the external drive, open a terminal and drop to root as in step 7.
Now we need to decrypt the LUKS partition again. In the root terminal, run the following, replacing the numeral 3 with the correct number for your partition. When prompted, enter the password you created that you're never going to forget again.
cryptsetup /dev/sda3 sda3_crypt
Next lets set some variables to simplify commands in the following steps. Run each of the following. You won't see output because it will be saved to variables

vg=$(pvscan | grep PV | tr -s ' ' | cut -f 5 -d ' ') <- save volume group name to $vg
export uuid=$(blkid | grep LUKS | grep -oP "\bUUID=\".*?\"" | tr -d '"' | cut -f 2 -d '=') <- save LUKS UUID to $uuid (that's all one line)

There is just one thing left to do, and that is to update the boot files, and to do that we need to mount some things. Run the following commands in the root terminal to mount everything. I'm going to use that partition information from my example. Change your commands accordingly.

mount /dev/mapper/${vg/-/--}-root /mnt
mount /dev/sda2 /mnt/boot
mount /dev/sda1 /mnt/boot/efi <- only do this for UEFI systems
mount --bind /dev /mnt/dev
mount --bind /run/lvm /mnt/run/lvm

Now we need to chroot into your actual system.
chroot /mnt
Make sure that the following commands are run inside this chroot'd terminal!
Now that we're in your system we need to mount a couple more things before we can update the boot files.

mount -t proc proc /proc
mount -t sysfs sys /sys
mount -t devpts devpts /dev/pts

Next we have to update the /etc/crypttab file with the UUID of the new LUKS partition.
sed -i "s/UUID=\([0-9a-f\-]\+\)/UUID=$uuid/" /etc/crypttab
Finally, we update the boot files.
update-initramfs -k all -c
update-grub


Unable to open /etc/ati/control, please reinstall the driver

Use this commands as root:

/usr/lib/fglrx/switchlibGL amd # or /usr/lib/fglrx/switchlibglx amd
reboot

And after rebooting, try to execute

aticonfig --initial


Using NIS client in Ubuntu 18.04 crashes both Gnome and Unity

I was also affected by this and at first I also solved this problem by commenting out

IPAdressDeny=Any in /lib/systemd/system/systemd-logind.service

like many others here mentioned before.

However, besides being a security risk, this will only work until the next update of the systemd toolchain rolls out, as mentioned in the Arch-Wiki. What the wiki does not explain very well, is how to extend the configuration of the systemd-logind.service such that a certain address range is whitelisted and that these settings will survive an update. After some reading in the RHEL documentation (especially section 10.6.4: Modifying Existing Unit Files), the following solution worked for me:

Create a new directory in /etc/systemd/system/ named exactly after the service you want to extend including a .d, here this would be: systemd-logind.service.d
Create a new file choose_an_appropriate_name.conf (e.g. nis_open_network_interface.conf) inside the newly created directory with the following content, which specifies the IP or IP range you want to be allowed:

[Service]
IPAddressAllow=10.10.0.0/16

Do a systemctl daemon-reload
And check if the new configuration is actually part of your systemd-logind.service unit using systemctl cat systemd-logind.service
Finally restart the service systemctl restart systemd-logind.service (This will kick you out of your running gnome session and you have to login again.)

There is no need to modify any other file! At this point you should be able to login with NIS-users again without getting a system freeze. Beware though, that this is still considered insecure (whitelisting IP addresses) and that the sandboxed behavior of systemd-logind is wanted. NIS/YP is kind of outdated but I still find it used ever so often. Also there may be a better solution to this involving a name caching daemon using nscd or sssd as mentioned in this systemd github issue dealing with the whole situation. But this is out of my scope at the moment.

This answer collects all the bits and pieces from previous posts and I hope clarifies a bit to give a good solution to the problem.

Cheers


If you want to simply ignore the F Lock key and get the same result whether it's on or off, you can use my rc.local file for just that purpose. I've verified in both X and VT that this works.


You probably have a blown /boot/initrd.img-4.15.0-74-generic file.

Use the GRUB Advanced Options menu, boot to kernel 4.15.0-70-generic.

Login in and open the terminal application.

ls -al /boot/initrd* # observe the file sizes

sudo update-initramfs -c -k 4.15.0-74-generic # recreate the file

sudo update-initramfs -c -k 4.15.0-72-generic # recreate the file

ls -al /boot/initrd* # observe the new file sizes

reboot # boot back into the normal Ubuntu kernel

Update #1:

Let's check your file system...

For 18.04 or newer...

boot to a Ubuntu Live DVD/USB
open a terminal window by pressing Ctrl+Alt+T
type sudo fdisk -l
identify the /dev/sdXX device name for your "Linux Filesystem"
type sudo fsck -f /dev/sdXX, replacing sdXX with the number you found earlier
repeat the fsck command if there were errors
and while you're booted to the Ubuntu Live DVD/USB, start the Disks application, and get screenshot(s) of the SMART Data window. Edit the screenshots into your question, or post them at imgur.com and give me the URL.
type reboot


Apache redirects all hosts to external url

If you're not using a local DNS server, you need to specify the local hosts in the /etc/hosts file. Just add

127.0.0.1      test.dev

as a new line to that file. Maybe you have to restart the Apache, but then test.dev should point to your local machine again.


Is there a restriction on the length of WPA passwords in Lubuntu?

I just booted up to the 19.04 desktop, entered my wifi pw and got connected with no problems.

So all is good now. If anyone has any idea why it didn't work in 16.04.3 please let me know, just to sate my curiosity.

Thanks everyone. I think I'll enjoy this community.

Goodbye Windows! Again...


Apach may be configured to disallow calling some command/libs...

But maybe environment variables (e.g. $PATH...) are not just the same for your user and Apach user (www-data) or something like that.

Here is an example what you can do to search the issue:

Try to call set or setenv to get the list of the variables.

Create a basic script callset.sh:

#!/bin/bash
set

(do not forget chmod +x callset.sh to give execution permission):

Then call this bash script from PHP:

$output = shell_exec ('/your/dir/callset.sh 2>&1');
echo $output

or

exec ("/your/dir/callset.sh", $output, $exitstatus);
print_r ($output);

Then check the difference with your own set call.

Finally provide the missing variables like that:

$output = shell_exec('PATH=aaa:bbb:ddd unoconv -f pdf test.odp 2>&1');


how do I install Ubuntu on a Macbook Pro 2011 (Early) without any third party apps?

I'm afraid you'll need rEFIt to be able to do the dual boot.


Stop an insolent narwhal from "correcting" monitor brightness?

You write much, and well, but say little :-p

What is your problem you wish to solve, exactly? As far as I know, the gnome power
manager is the place that controls the brightness depending on things like are you
connected to AC or not. There are also knobs in there for how long to wait before dimming
the display, or not at all.

Press Super and type in "power", only one app will show up, there's the extent of the
brightness control.


Creating properly aligned partitions on a replacement disk

I just had to replace the mirror in one of my arrays today, and I opted to just fdisk the replacement instead of using sfdisk.  Since I know the partition sizes (its just one, in my case) and I went with a bigger drive for the replacement.

Original is RAID1 of a pair of ST31500341AS, and replacement disk is an ST2000DL003.

So, what I did was:

mdadm /dev/md6 --fail /dev/sde1
mdadm /dev/md6 --remove /dev/sde1
replace /dev/sde
fdisk /dev/sde

c
u
n
p
1
enter (for 2048)
3907028736
t
fd
w

This results in new partition with start 2048 and end 3907029167 - for 1953513560 blocks (or 244189195 in 4k blocks) 3907028904 - for 1953513428 blocks (244189178 in 4k blocks).  The old partition was start 63 and end 2930272064 with 1465136001 blocks.  I think lvm takes care of being aligned with the space, so it should all be good.

Forgot that I can't go all the way to the end of the disk, otherwise mdadm will switch to using the whole disk rather than the partition on reboot.  LVM seems to tolerate this shift, but putting a filesystem directly onto the MD didn't.  Recommendation was to shorten the partition by at least 256 sectors, so I did (3907029167-256)/8*8 in bc to get 3907028904.  Resulting partition is mod 8 == 0, and short by 263 sectors.  This problem got me when I did this for another array :(
mdadm /dev/md6 --add /dev/sde1
watch the array rebuild.  Seems to be rebuilding at a pretty good speed, seems faster than it was with the old drive.
and then remove and readd the other side, so that the superblocks will match.


I solved my own issue - When Chrome installs, it creates a directory /etc/opt/google/chrome.

The instructions clearly state to create the policy directories in /etc/opt/chrome, but I overthought it and placed them in /etc/opt/google/chrome.

Once I moved them to /etc/opt/chrome/ it worked!


I attempted to install cuda drivers, and now almost everything is broken

I had the same issue -- check your bios and you may need to disable Secure Boot from there specifically.

This fixed my issue on Ubuntu 16.04 after switching to Nvidia drivers for CUDA.


Changing default "Open With" to a console based application

You could create a own desktop file in /usr/share/applications or ~/.local/share/applications. The easiest way is to copy an existing file. Open the file with root permission in your preferred editor (gedit/nano/...) and adapt the fields.
Important is the Exec line. Here goes the command to be executed, where %f represents the file to be opened.


How to move calanders from Evolution to Lightning

In Evolution, save the calendar as an .ics file as follows:

In Calendars, right click on the calendar you wish to transfer and select Save As
Save the calendar as a file of the iCalendar (.ics) file type

In Thunderbird, import the file you just saved as follows:

Go to the Events and Tasks menu and click on Import...
Select the iCalendar (*.ics) file type in the import dialog and import the file saved from Evolution


Direct remote access (ssh) with Raspberry Pi running Ubuntu server 20.04.1

Solution: I needed to configure static IP addresses correctly. I used this tutorial: (https://linuxize.com/post/how-to-configure-static-ip-address-on-ubuntu-20-04/). The only thing I did differently were the exact addresses and changed "ens3" to "eth0" in the .yaml-file as it was how the ethernet connection appeared on my RPi. I can now ssh straight into my Pi through an ethernet cable without a switch.


Is it possible to boot the same ubuntu sometimes as a virtual machine, and sometimes on the physical pc?

[Please note that I have never booted an OS off a phyiscal drive using a vm but it can be done.]

You can assign a vm to use a hard drive partition directly rather than a .vdi, .vhd, or .vdmk file. You can do this under the VM settings in Vmware player by adding a generic scsi device and choosing the partition you want. Please note that the vm only has access to that partition which presents a few problems:

On BIOS computers the bootloader is stored on the hard drives mbr and therefore will not be available to the vm making the OS unbootable. You will need to create a virtual hard drive that has a bootloader setup to boot an os from the scsi device. On UEFI systems a similar problem will occur.
The swap parition won't be available, I'm not familiar enough with swap to suggest a work-around for this. Missing swap won't prevent booting, but you should get an error message at least the first time, and it will affect performance of the VM if you don't have a swap partition.


You cannot rezise your partition if it is mounted and being used. Do this:

Put the Ubuntu live CD and boot with it
Open GPARTED
Destroy the other partition you won't use (Other OS)
Resize your ubuntu partition to fill up the unpartitioned part or your HD

I usually use /home in a different partition, but you can do it anyway.


Ubuntu 14.04 blank desktop screen after Virtualbox was installed and updated Ubuntu

Try following the answer on AskUbuntu Post and see if your desktop Unity is back.
If you get to step 5 in the following link, but do not see Unity on the list try this: sudo apt-get -f install && sudo apt-get --reinstall install unity


Vulkan driver stops working when running in google remote desktop

I figured out a way to get it to work but it is pretty hacky. I do not reccommand this for sensitive systems

It all started with this page that tells us

  If the X11 server associated with dpy does not own display, or if permission to access it has already been acquired by another entity, the call must return the error code VK_ERROR_INITIALIZATION_FAILED.

This lead me to this question and this command: ps -ef | grep X. This showed that the current display was started using xvfb. This is the x virtual frame buffer. Apparently xvbf does not support vulkan. So let's see if we can make google-remote-desktop make use a normal x server (spoiler: yes!).

The code behind the chrome-remote-desktop service is in /etc/init.d/chrome-remote-desktop, which in turn runs /opt/google/chrome-remote-desktop/chrome-remote-desktop (sourcecode). In there we find that we can use the CHROME_REMOTE_DESKTOP_USE_XORG environment variable to make google-remote-desktop launch an Xorg display with the dummy driver. Let's enable it by adding the following line to the /etc/environment file:

CHROME_REMOTE_DESKTOP_USE_XORG=1

After restarting the service I got the following error

Only console users are allowed to run the X server

Why is X server not started by root? Because the chrome-remote-desktop service starts a separate display for each user in the name of that user.

To fix above error you can edit /etc/X11/Xwrapper.config and set allowed_users = anybody.

Now X server is complaining that the -logfile is only available when the server is run as root (i.e, with real-uid 0). If you are like me and don't care about logging you can edit /opt/google/chrome-remote-desktop/chrome-remote-desktop and remove the following line (around line number 581):

"-logfile", "/dev/null",

Almost there!

Now X server is complaning that the -config must be a relative path. This page explains that the config file must be placed in /etc/X11/<cmdline> or /usr/etc/X11/<cmdline>. Looking through the sourcecode of /opt/google/chrome-remote-desktop/chrome-remote-desktop we see the following:

    with tempfile.NamedTemporaryFile(
        prefix="chrome_remote_desktop_",
        suffix=".conf", delete=False) as config_file:
      config_file.write(gen_xorg_config(self.sizes).encode())

At this moment the config file is created in /tmp, so let's move that. Add the following line between the prefix and suffix line:

dir="/etc/X11/",

X wants to receive a relative path so we have to change

"-config", config_file.name

to

"-config", os.path.basename(config_file.name)

And because we are not root we must give users write permission to this folder. So let's run:

sudo chmod 777 /etc/X11

We are doing all this so that we can use the nvidia drivers. Replace the dummy driver:

      'Section "Device"\n'
      '  Identifier "Chrome Remote Desktop Videocard"\n'
      '  Driver "dummy"\n'
      '  VideoRam {video_ram}\n'
      'EndSection\n'

with the nvidia driver:

      'Section "Device"\n'
      '  Identifier "Chrome Remote Desktop Videocard"\n'
      '  Driver "nvidia"\n'
      '  VendorName "NVIDIA Corporation"\n'
      '  VideoRam {video_ram}\n'
      'EndSection\n'

Somehow this setup does not like resizing, therefore I forced a single size by setting DEFAULT_SIZES_XORG to "1920x1080".

And now it works!


Installing Ubuntu on freeDOS msi PE72 7RD

I just needed it a USB 3. And nothing to change on the BIOS, only the boot option.


It looks like you tried to install the adobe-flashplugin package for focal on a bionic install.
Do it the right way instead: Enable Canonical Partner and then install the bionic version of adobe-flashplugin from there.
More reading about Flash:
https://help.ubuntu.com/stable/ubuntu-help/net-install-flash.html


Why can I ssh into my server after I physically restart it, but not after I reboot via ssh?

It could have something to do with your server switching internal ip address. Try setting your server to a fixed address.


How to add ssh key info @ Juju Charm for AWS

You're probably looking for juju add-ssh-key <key>

https://jujucharms.com/docs/2.0/commands#add-ssh-key

See also:

https://jujucharms.com/docs/2.0/commands#list-ssh-keys
https://jujucharms.com/docs/2.0/commands#remove-ssh-key

However, if you set up your ssh credentials when you bootstrapped with the same keys then Juju's already using those for authentication, then you can just ssh to whatever unit you'd like, like juju ssh mysql/0 for example:

How to SSH into a Juju instance?


Nope, Windows can't create Linux-format partitions.

If it's unallocated, you can allocate and format it from Ubuntu. If it's currently formatted as something else that you want to repurpose, you may be able to unmount it while in Ubuntu and free it up.

But if all else fails, the LiveCD will let you do anything because nothing on the disk will be mounted by default.


Server certificate verification failed when updating

It turns out that the issue was not with the certificates. The default gateway of the Ubuntu box is running a transparent proxy and after adding the Ubuntu box to the addresses that bypass the proxy, this fixed the problem.


Virtual terminal (CTRL+ALT+(Fx) doesn't work

Maybe that's all your supposed to see. Try typing in your user name and see what happens. You may have to log in even though your computer isn't telling you that for some reason.

If you want your regular display back, simply press ALT+F7


gksudo nautilus won't let me change permissions of a folder owned by root

I solved the problem by remounting the hard drive. Zanna posted a thread that pointed me in the right direction. That thread's suggestion of changing fstab lead to a two hour nightmare where my machine wouldn't boot.

Once I discovered the relevant Ubuntu documentation, I was able to use this line for my vfat partition in /etc/fstab.

/dev/sda5 on /media/mynewdrive type vfat (rw,nosuid,nodev,uhelper=hal,shortname=mixed,uid=1000,utf8,umask=077,flush)


As per your comment, $file contains a path output of find. That path is likely to contain spaces.

Using a path containing spaces in a command is likely to break it. So just enclose the path into double quotes:

$ff = '/usr/bin/ffmpeg -i "'.$file.'"  -vcodec libx264 -pix_fmt yuv420p -profile:v baseline -level 3.0 -s '.$RESOLUTION.' -vb '.$VB.'k -ac 2 -acodec aac -b:a 128k -ar 44100 -strict -2  -vf "movie=/datastore/logo/hello_logo.png [watermark]; [in][watermark] overlay=60:main_h-overlay_h-60 [out]"  /tmp/'.$MXF.'.mp4 -y';


Can the "Starred" folder in the left pane of Files (nautilus) be removed?

There are a couple of not that trivial ways to remove the "Starred" item in the left bar of nautilus. The second option involves editing source code and recompiling. I will only cover the first way here.
1 - Create a folder to store the override
mkdir ~/.config/nautilus/ui

2 - Extract the resource description of the main window:
gresource extract /bin/nautilus \
/org/gnome/nautilus/ui/nautilus-window.ui \
> ~/.config/nautilus/ui/nautilus-window.ui

3 - Edit the properties of the GtkPlacesSidebar object: open the file you created in the previous step:
gedit ~/.config/nautilus/ui/nautilus-window.ui

and change the property show-starred-location to false as in following code snippet:
<object class="GtkPlacesSidebar" id="places_sidebar">
...
<property name="show-recent">False</property>
<property name="show-starred-location">False</property>
...
</object>

4 - Set the environment variable to make GLib use this override:
export G_RESOURCE_OVERLAYS="/org/gnome/nautilus/ui=$HOME/.config/nautilus/ui"

5 - You also need to set this via ~/.pam_environment, because Nautilus is started via D-Bus:
gedit ~/.pam_environment

and add following line
G_RESOURCE_OVERLAYS DEFAULT="/org/gnome/nautilus/ui=/home/confetti/.config/nautilus/ui"

where you change "confetti" by your own login name.
(with thanks to JusticeforMonica and DK Bose for the hints)
You need to log out and back in before this will take effect.


Why isn't there an option for installing alongside an os anymore?

Options appear when that option has a situation that validates that option to show.

Odd sentence I know. So with some examples ...

Replace Ubuntu only appears when you have another Ubuntu installed.
Replace windows only appears when you have a windows system installed.

And in your case ...

The OS you currently have installed probably takes up ALL of your partitions. For "install alongside" to appear there needs to be a partition to install your 2nd operating next to. In other words: you need "unallocated space" or an empty partition.


Upgraded to 12.04, still displays the old login screen

You could try, in a terminal:sudo apt-get update && sudo apt-get dist-upgrade
Which may help, or at least give some clues.


Cannot connect to online accounts in Empathy (Ubuntu 12.10)

Try removing the folders .mission-control, .config/Empathy, .local/share/telepathy and .cache/telepathy from your home folder (this will reset Empathys and probably also Gwibbers accounts + Empathys settings):

rm -rf .mission-control .config/Empathy .local/share/telepathy .cache/telepathy

Then log out, log in again and readd your accounts.


How to make Ubuntu File Manager show the "real" path after opening a shortcut link?

You can achieve this by using a bind mount since linux 2.4

Test it with this:

sudo mount --bind /var/www/html /home/Desktop/html

Make it permanent by adding this line to your fstab after /home and /var:

/var/www/html /home/Desktop/html defaults,bind 0 0


how to set priviledge on port 21 ftp of a host

Enable fw

sudo ufw enable

To allow packets from xxx.xxx.xxx.xxx

sudo ufw allow from xxx.xxx.xxx.xxx

To allow packets from network xxx.xxx.xxx.xxx/24

sudo ufw allow from xxx.xxx.xxx.xxx/24

allow IP address xxx.xxx.xxx.xxx access to port 21 for all protocols

sudo ufw allow from xxx.xxx.xxx.xxx to any port 21

allow IP address xxx.xxx.xxx.xxx access to port 21 using TCP

sudo ufw allow from xxx.xxx.xxx.xxx to any port 21 proto tcp


Sending enter in interaction mode ubuntu 13.10

Basically you have to preseed the answer for debconf:

sudo apt-get install debconf-utils
echo "ocsinventory-agent ocsinventory-agent/method select local" | sudo debconf-set-selections
sudo apt-get install -y --force-yes ocsinventory-agent

You can obviously change local by server for your needs.


I tried

  Settings | Printers | Tools Cog | Printer Details

and then

  Install PPD File | Location
  and in location pasted a PPD in my home folder.
  This didn't work, perhaps because of permissions.

I also tried direct copy of PPD file into /usr/share/cups/model, and that didn't work.

But after I did system-config-printer, the printer because visible. I suspect that

  Settings | Printers | Tools Cog | Printer Details
  assumes that the correct PPD file is already in the correct location.


Manually upgraded QEMU 3.1 does not support qxl video device

I got the similar error after building QEMU from sources. It needs every dependency already installed in the system when calling "./configure" because this is the step that detects system capabilities. If you compile QEMU and then install dependencies like spice, qxl, etc it won't detect them later and you need to recompile.


Ubuntu 16.04 kernel 4.4.0-21 not loading nvidia/vboxdrv modules anymore (Required key not available)

There is a way to leave secure boot on and use proprietary kernel modules like NVidia or VirtualBox. First download xca app:

sudo apt install xca

Then create new database and generate new key. Next generate CA certificate from that private key. Export private key to PEM format and CA public cert to DER format. Import CA cert to MOK database:

sudo mokutil --import CAcert.cer

Program asks you for password for MOK database. After reboot MOKManager will be executed before GRUB. Select Enroll keys, select cert that you add before and enter password for confirmation. After that your CA cert is added to MOK database. Reboot.

Next find sign-file program in kernel headers scripts directory. For me it is in:

/usr/src/linux-headers-4.4.0-22-lowlatency/scripts/sign-file

Now sign all kernel modules in /lib/modules/4.4.0-22-lowlatency/updates/dkms/. For example:

/usr/src/linux-headers-4.4.0-22-lowlatency/scripts/sign-file sha256 CA.pem CAcert.cer /lib/modules/4.4.0-22-lowlatency/updates/dkms/nvidia_361.ko

After that you will be able to load module without Required key not available error.

After install new kernel or new version of module kernels from dkms directory you must repeat signing procedure.

Links to read to clarify:

https://wiki.ubuntu.com/SecurityTeam/SecureBoot

https://access.redhat.com/documentation/en-US/Red_Hat_Enterprise_Linux/7/html/System_Administrators_Guide/sect-signing-kernel-modules-for-secure-boot.html


How do I manage how many revisions snapd keeps of an application?

Snapd will automatically retain three revisions (usually current plus two older) by default, and will delete older.

In mid-2018, snapd was updated so that the number of revisions is configurable (though never less than 2).

Use the command:

snap set system refresh.retain=N

N cannot be less than two.


Unload saa7164 module for Hauppauge 2250, and stop tvheadend to suspend Ubuntu 15.04

I think you also need to stop any program that is using the module, before you remove it. You aren't running MythTV by any chance?


Update to 13.10 failed via update manager

You just have to disable the CD/DVD entry in: Software Center>Edit menu>Sources


Open nautilus. In the side bar is a list of external drives. Click the Eject (⏏) button.

If you can't see this, press F9.

This only applys to storage devices.

Open Terminal (Ctrl+Alt+T)

Run the command xinput:

$ xinput

⎡ Virtual core pointer                          id=2    [master pointer  (3)]
⎜    Virtual core XTEST pointer                 id=4    [slave  pointer  (2)]
⎜    Mitsumi Electric Apple Optical USB Mouse   id=9    [slave  pointer  (2)]
⎜    Microsoft Trackball Explorer®              id=10   [slave  pointer  (2)]
⎣ Virtual core keyboard                         id=3    [master keyboard (2)]
     Virtual core XTEST keyboard                id=5    [slave  keyboard (3)]
     Power Button                               id=6    [slave  keyboard (3)]
     Power Button                               id=7    [slave  keyboard (3)]
     UVC Camera (046d:08c9)                     id=8    [slave  keyboard (3)]
     BTC USB Multimedia Keyboard                id=11   [slave  keyboard (3)]
     BTC USB Multimedia Keyboard                id=12   [slave  keyboard (3)]
     Eee PC WMI hotkeys                         id=13   [slave  keyboard (3)]

You should be able to see it there, for example my mouse is a Microsoft Trackball Explorer® and it has an id of 10.

Yours will also have an id. Run the following command:

xinput disable <ID>

then to enable it (if you want)

xinput enable <ID>

a restart also resets this, so they will all become active again.


Second screen tearing AMD Radeon 5800 HD Ubuntu 12.10

I am one of the few who also use an HD 5800 card (5830) with Ubuntu in a dual screen configuration. I had the exact same problems as you when I started, and wracked my brains trying to solve it with very little response from the forums.

Several months later I am hanging in there, and managed to solve the problems well enough, but I still lack the ability to do fairly normal things on more common operating systems: play HD videos, scroll quickly down a document/webpage with tearing ect... If you are still looking for help, I might be able to get you as far as I have come (much better).

I have to say, having done it alone, I would go as far as to recommend selling that 5800 series GPU while there is a strong market for it, and buying something else. I am using the Ubuntu provided fglrx repository, and I about to test the xvba-video package. Perhaps this (and emerging gaming on linux focus) will lend some more function for our otherwise awesome video cards.

Here is some information:

Xorg.conf

  Section "ServerLayout"
    Identifier     "aticonfig Layout"
    Screen      0  "aticonfig-Screen[0]-0" 0 0
    EndSection
  Section "Module"
    EndSection
  Section "Monitor"
    Identifier   "aticonfig-Monitor[0]-0"
    Option      "VendorName" "ATI Proprietary Driver"
    Option      "ModelName" "Generic Autodetecting Monitor"
    Option      "DPMS" "true"
    EndSection
  Section "Monitor"
    Identifier   "0-CRT1"
    Option      "VendorName" "ATI Proprietary Driver"
    Option      "ModelName" "Generic Autodetecting Monitor"
    Option      "DPMS" "true"
    Option      "TargetRefresh" "60"
    Option      "Position" "1920 0"
    Option      "Rotate" "normal"
    Option      "Disable" "false"
    Option      "PreferredMode" "1280x1024"
    EndSection
  Section "Device"
    Identifier  "aticonfig-Device[0]-0"
    Driver      "fglrx"
    Option      "Monitor-DFP2" "0-DFP2"
    Option      "Monitor-CRT1" "0-CRT1"
    BusID       "PCI:1:0:0"
    EndSection
  Section "Device"
    Identifier  "amdcccle-Device[1]-1"
    Driver      "fglrx"
    Option      "Monitor-CRT1" "0-CRT1"
    BusID       "PCI:1:0:0"
    Screen      1
    EndSection
  Section "Screen"
    Identifier "aticonfig-Screen[0]-0"
    Device     "aticonfig-Device[0]-0"
    DefaultDepth     24
    SubSection "Display"
            Viewport   0 0
            Virtual   3200 3200
            Depth     24
    EndSubSection
    EndSection
  Section "Screen"
    Identifier "amdcccle-Screen[1]-1"
    Device     "amdcccle-Device[1]-1"
    DefaultDepth     24
    SubSection "Display"
            Viewport   0 0
            Depth     24
    EndSubSection
    EndSection

fglrxinfo:

display: :0  screen: 0
OpenGL vendor string: Advanced Micro Devices, Inc.
OpenGL renderer string: ATI Radeon HD 5800 Series
OpenGL version string: 4.2.12002 Compatibility Profile Context 9.00.11

Next we can work out the Catalyst Control Center settings if you decide you want to keep the card.
Good luck =)


The module-loopback is used to

  route audio from a source directly back to a sink.

The way you issued it you are trying to loop an output sink to an input device. This obviously won't work, thus the "initialization failed" error.

In case you want to have your audio on both sinks, the local sound card, and the bluetooth receiver use module-combine-sink.

To connect to a bluetooth sink you need to have this sink recognized by pulseaudio. Check with the following command if this sink is present before you try to connect to it:

pacmd list-sinks

If you can see your Bluetooth receiver you can connect it outlined in my answer to this question:

How to change pulseaudio sink with  "pacmd set-default-sink" during playback?

In case your receiver is not listed there may be an issue connecting it to Bluetooth  (Bluez/Blueman depending on your distribution). You may then try if removing the device from the list of known devices and redoing the pairing process helps.


How do I install Sublime Text 2 full version?

Purchase a license by visiting here. You'll get a license key. Then open up Sublime Text, go to Help > Enter License.


how do I limit the number of open torrents in transmission?

First, add the PPA and update if you haven't already (Close transmission first):
Command line way:

sudo add-apt-repository ppa:transmissionbt/ppa
sudo apt-get update
sudo apt-get install transmission-gtk transmission-common

Or:

Open Update Manager.
Click "Settings".
Click "Other Sources".
Click "Add".
Enter (change oneiric to your version if different):

deb http://ppa.launchpad.net/transmissionbt/ppa/ubuntu oneiric main
deb-src http://ppa.launchpad.net/transmissionbt/ppa/ubuntu oneiric main
Close Settings Window.
Click "Check".
Once complete, click "Install Updates".

Second, Edit the Preferences in Transmission:
 1. Open Transmission.
 2. Open "Edit" ➜ "Prefernces".
 3. Under the "Downloading" Tab, Under "Queue", set "Maximum Active Downloads" to the limit you desire.


open terminal by ALT + CTRL + T then type :

sudo shutdown -P now

If it works, no worries. Else, you need to try Step 1 and 2 along with the Note provided below. With these my shutdown problem is a thing of the past.

Step 1: Alt+CTRL+T: to open a terminal and type

sudo gedit /etc/default/grub

It will open the grub file. Change the line

 GRUB_CMDLINE_LINUX_DEFAULT="quiet splash"

to

 GRUB_CMDLINE_LINUX_DEFAULT="quiet splash" acpi=force apm=power_off

and close it after saving.

Step 2: open terminal and type

sudo gedit /etc/modules

It will open the modules - just type apm power_off=1 below lp and save the file.

Step 3: Next type in the terminal

sudo update-grub


There is usually a way, depending on the file manager you are using, to have it show the hidden files.  You can use CTRL-h, or select "View->Show Hidden Files" in most file managers.

That being said, even if your file requester or manager doesn't have that capability, you can always still specify the filename directly on the command line. For example, if you are using the xed text editor, then the command line in a terminal window...

$ xed ~/.bashrc

...will load up your .bashrc file in the editor.


How can I encrypt the entire disk while installing Ubuntu?

This will not affect your boot system, because this will only encrypt the Ubuntu partition. It won't encrypt the boot or Windows partitions.
So you can install Ubuntu alongside Windows or as unique OS without any problem.
You don't need to remove any OS. If you have enough free space in your disk, then you are done!
For Ubuntu 12.10:
This feature can be enabled using any Live Edition (LiveUSB, LiveCD, LiveDVD).
During the installation of Ubuntu, in the Installation Type step you will see a similar window like this:

You have to activate the Encrypt the new Ubuntu installation for Security option. Then Ubuntu will choice the encryption type automatically.
For Ubuntu 12.04 and older:
You need to use the Ubuntu Alternate CD. You can download this selecting your version in old-release or release pages. Follow the instructions mentioned in this question.


How do I install Intel ethernet drivers?

modprobe program to add and remove modules from the Linux Kernel. You can find more details using command man modprobe.

ifconfig eth0 up - It is same as enable a Ethernet device in windows.

dhclient eth0 is to get dynamic ip from your router.

ping intel.com to confirm that you can connect to intel.com i.e. Internet.

Now to do a modprobe automatically, edit rc.local file. rc.local file is special file that runs when you logon.

So run this command,

gksu gedit /etc/rc.local

at the end of this file before the line exit 0 enter a line like this

modprobe e1000e
exit 0

What the thing is kernel update and blah blah..

Kernel is the core of any operating system. So if the core changes all drivers must be compatible with it. Ubuntu provides update of kernels for stability and security. The kernel version is mentioned in grub menu like this text 3.2.0-25-generic . As you are building the driver yourself so any with any change in kernel you have to recompile the driver to make it compatible and include in this new kernel.basically you have to do the steps you did before modprobe. :)

Let me know if you need more clarification.

Anyway, did you check Additional drivers (press Win and type it), Ubuntu community might provide the drivers. In that case you don't need to do anything. It will be updated and maintained automatically.


Ctrl+A key (sellect all) doesnt work in Ubuntu 19.04 GoogleChrome

The problem was with theming. I've changed my theme to default and everything is fine right now.

gsettings set org.gnome.desktop.interface gtk-key-theme "Default"


how to change display name or nickname of ubuntu server? (AWS EC2)

What you are trying to change is the PS1 variable.
It is not an environment variable but a bash shell variable.
If you are interested in learning more about that look here.

To be brief, if you want to just change the part where traditionally you'll see the server name, just to the following:

1 In a terminal echo $PS1.
You will probably see something like:

\[\e]0;\u@\h: \w\a\]${debian_chroot:+($debian_chroot)}\[\033[01;32m\]\u@\h\[\033[00m\]:\[\033[01;34m\]\w\[\033[00m\]\$

In it \u stands for Username and \h stands for Hostname.

2 Still in the terminal try doing:

PS1="\[\e]0;\u@\What you want the hostname to be: \w\a\]${debian_chroot:+($debian_chroot)}\[\033[01;32m\]\u@What you want the hostname to be\[\033[00m\]:\[\033[01;34m\]\w\[\033[00m\]\$"

Notice the quotes that need to be added here but won't be in stage 3.

3 When you are satisfied with the results go to your .bashrc file and replace what it says in the line where PS1 is defined. Notice that it appears several times in the file and that each one should be changed differently and separately (ideally, at least).
Save and quit the file.

4 Type . ~/.bashrc, this should reload the file and start presenting the prompt you have set.
All we did currently will change it for your user. It will not change it for the root user.
To do that you must edit the file /root/.bashrc in a similar fashion.

Good luck!


ltsp-server-standalone uninstallable on 12,04

I recommend you install Ubuntu 14.04 LTS since it provides the same stability as 12.04 LTS, newer packages, and will last you past the upcoming EOL of Ubuntu 12.04. Additionally, more people will be able to provide support to Ubuntu 14.04, and most guides written for 12.04 should be compatible with 14.04, give or take a few things.

However, if you insist on using 12.04, using:

apt-get clean

as root (e.g. sudo) and:

apt-get -f install

(again as root) should fix this issue.

Then attempt to install ltsp-server-standalone. If those two commands did not resolve the issue for you, check here for additional troubleshooting.


Wireless adaptor (TL-WN8200ND) shows the networks but wont connect

Please implement the fix outlined here: Ubuntu GNOME 17.04: wi-fi not working -- mac address keeps changing?

Next, please check to see if two possibly conflicting drivers are loaded:

lsmod | grep rtl

If you find that both rtl8192cu and rtl8xxxu are loaded, then blacklist one:

sudo -i
echo "blacklist rtl8192cu"  >>  /etc/modprobe.d/blacklist.conf
exit

After making these two changes, reboot and let us hear the result.


Is it possible to use a lib included in a framework in a snap in Ubuntu Core?

We're going to add this ability, but the library will only be exposed to YOUR snaps, not snaps from anybody else. The idea is to enable you to get code and file sharing across a set of snaps without creating the sort of brittle version dependencies that plague the traditional OS.

This way, you can update the library or the app at any time, and since you control both, you can make sure you don't break yourself in doing so.


Black screen when watching a video on Youtube

It is better to install Google Chrome. You don't need to worry about flash plugin or anything. Videos can be played easily.


17.1 Wlp6s0: failed to remove key (1, ff:ff:ff:ff:ff:ff) from hardware (-22)

3 ways to fix this problem:

First way: If you don't wanna make change to grub or changing the grub create other problems or you don't wanna upgrade the kernel:

Everytime when you see that error after turning off the pc,just press
alt+F7.

Second way: Removing "quiet splash" from the parameters in grub:

gksudo gedit /etc/default/grub

Change:

GRUB_CMDLINE_LINUX_DEFAULT="quiet splash"

To:

GRUB_CMDLINE_LINUX_DEFAULT=""

Then run:

sudo update-grub
reboot

Third way:

Upgrade to kernel 4.13.6 or higher.


mysqldump on a production server does not work with sudo. Please try this:

$ sudo su
# mysqldump database> database.sql


Ubuntu on VirtualBox leads to a black screen

@ OP -

Have you checked your BIOS of the host machine to enable virtualization technology?   I had the same issue.  I took notice when I could only install 32-bit systems even though I run a 64-bit environment.  If you can, get to the BIOS, enable the Virtualization Technology (Intel VT or AMD-V) and then try again.   I did the above step and I am running the install with no problems and I have the option now to select 32-bit or 64-bit installs.

Cheers.


How to access a Windows share via Linux?

To mount a share via fstab, you should:

create a mount point (directory) to mount the share into. I am not sure if /mnt/share/ exists?
use forward slash
add the ip address of the share before the share name in the fstab file.
if not installed already: install cifs utils
for a guest account (unprotected share), you should use guest,uid=1000 as user id, to make the guest owner.
to enter a password protected share, you need to set the user id to the share's user name and the reference to a credentials file (see example below)

As an example, my line in the fsatb file looks like (the \040 is an escape for the space):

//192.168.0.104/werkmap_documenten/documenten\040Jacob /home/jacob/Netwerkmap cifs auto,iocharset=utf8,uid=jacob,gid=users,credentials=/root/.cifscredentials,file_mode=0775,dir_mode=0775 0 0


Setting Ubuntu As The Default Operating System When Using The Windows Installer

I normally use a program called EasyBCD to change the boot entries. You can choose Ubuntu to be the default OS in that program. More info here


What credential is my server looking for?

If you use the same username / password in windows and samba, when asked for credentials, just enter your username and no password.  This did the trick for me (after long search).


How do I launch Chromium with multiple tabs open using the main menu?

If you want to start chromium with multiple tabs open, this is what your command will look like:

chromium-browser http://google.com/ http://bing.com/ http://yahoo.com/

See How can I add and change items in my Applications Menu? on how to create a short-cut.


How can I start a different X session on tty8?

To start a new X session on tty8, drop to tty1 (or 2-6) and type

startx -- :1


Command to append line to a text file without opening an editor

You can append a line of text to a file by using the >> operator:

echo "hello world" >> my_file.txt

or in your case

echo "alias list='ls -cl --group-directories-first'" >> config.fish

Please take note of the different types of quotes.


bluetooth headset can connect, but not visible in pulse audio

I had the same issue, this helped:

sudo apt-get-install pulseaudio-module-bluetooth

and then reboot, restart bluetoothd, etc, etc, and then your headset is visible.


How to add icons to the launcher on Ubuntu Touch?

In recent builds, when you launch an app from the dash it's icon will appear in the Launcher while it is running.  You can then long-press on it's icon to get a menu which has an option to "Pin to Launcher".


HTML5 DRM video won't play on Ubuntu 15.10 with latest Google-Chrome

I also asked here:
https://productforums.google.com/forum/?utm_medium=email&utm_source=footer#!msg/chrome/QUPNuAndwAI/X9--o_OuBQAJ
JPApen suggested I install google-chrome-beta instead of google-chrome-stable and that fixed it - yay!  They also said that google-chrome-stable would have this fixed in a couple weeks (today is 2016-02-14)
Details
I opened "Software & Updates" from the dash, picked the "Other Software" tab, clicked the Add button, and where it says "apt line" I put:
http://dl.google.com/linux/chrome/deb/ beta main

That's the same as the stable apt line except for the word beta.
Then from a command line:
sudo apt-get remove google-chrome-stable
sudo apt-get install google-chrome-beta

I actually used purge instead of remove because this is a relatively new installation and I didn't care about keeping my settings.  Note that purge now removes your repository as well.
I did NOT need

hal
to be signed into chrome
flashplugin-installer or any kind of flash (I think)


Merge Multiple Documents and Convert to One Pdf in LibreOffice from Terminal

Maybe you could use an additional tool, like pdftk for instance, to do the merging part. You could then chain the two commands; the first one with Libreoffice, the second one with pdftk.


Sound problems after installing ubuntu 20.04 from scratch (no input and no output devices)

I have same situation on ubuntu 18.04 sound work, after install (not update) 20.04 - no sound devices - usb / pci build in, hdmi all ignored


What is the difference between "cd \" and "cd /" commands in ubuntu terminal?

In Bash, your shell, the \ (backslash) denotes an escape character. This should be used in cases where you want to escape characters like spaces, quotes and other characters meaningful to the shell syntax, but you want to have it propagate as data to the command you're running. By having this as the last character on the line you're escaping the newline and Bash is waiting for further input (multiple lines).

/ is just a forward slash (meaning directory separator). With just / this means the root, so for example ls / lists the contents of the root. By changing the working directory to /, the indicator in your shell also changes from ~ (short for home directory, e.g. /home/gert/) to the directory you're in then (/).

Demo

$ touch a filename with spaces
$ ls -l
total 0
-rw-rw-r-- 1 gert gert 0 Jul  1 02:33 a
-rw-rw-r-- 1 gert gert 0 Jul  1 02:33 filename
-rw-rw-r-- 1 gert gert 0 Jul  1 02:33 spaces
-rw-rw-r-- 1 gert gert 0 Jul  1 02:33 with

Oh noes, it was my intention to create one file with the name a filename with spaces. So, here we use the \ to escape the spaces. This prevents the shell to provide four arguments to touch, but instead provide a single one with the spaces included.

touch a\ filename\ with\ spaces

$ touch a\ filename\ with\ spaces
$ ls -al
total 24
drwxrwxr-x  2 gert gert  4096 Jul  1 02:35 .
drwxrwxr-x 55 gert gert 20480 Jul  1 02:33 ..
-rw-rw-r--  1 gert gert     0 Jul  1 02:35 a filename with spaces

Of course, by using quotes (touch "a filename with spaces") one can achieve the same thing.

It is also used to declare special characters like newlines:

$ echo -e "bla\nnewline" # \n means a newline character
bla
newline

We need the -e option here for echo, because as the manpage put it: -e     enable interpretation of backslash escapes.


Can I reorder an application search result?

I think that unity will use what you most used.

It remember what it's the application that you normally click when typed some words and then bring it to first place (and the same with second, etc).

In my desktop, when I type "calc" it's libre office calc what appear first.

I have searched a little more and found that unity app lens have a bug related:
https://bugs.launchpad.net/ubuntu/+source/unity-place-applications/+bug/737394

Most frequently used app is only updated when an app it's installed or removed.


Deleted everything in Jupyter, cannot recover files from Trash

Regarding ...
paul@Paul:~$ cd Desktop
bash: cd: Desktop: Not a directory
paul@Paul:~$ mkdir Desktop
mkdir: cannot create directory ‘Desktop’: File exists

That means Desktop exists and is not a directory... so it is a file (like the last line tell you ;))
Do
ls -l Desktop

If it is a file checks its contents. If empty(!)
rm Desktop

After that go to the trash directory and check it contents; then find the place it should belong and use cp -R with the files and destination to copy them back.


Copy an image of a disk to an external drive

The error was overcome with the suggestion to "quote" the path

so:

dd if=/dev/sda | gzip - c > "/media/mark/Seagate Expansion Drive/ssd.img.gz"

is currently building an archive (finally).


What does Ubuntu iso "desktop image " mean?

After reading it, I assume "desktop" means the Desktop Computer or PC. The other version available is the Server edition, which is without GUI (as I understand after visiting this site for two months).

It IS a Live CD but of the desktop version.


Ubuntu won't connect to Network through Ethernet

These steps worked for me, but YMMV.

Keep your computer on. Leave it idle and watch the WiFi Signal icon. Keep your ethernet cable connected.

Reboot your router by unplugging it, waiting 30 seconds, and plugging it back in.


dpkg-divert: error: rename involves overwriting `/usr/lib/xorg/protocol.txt' with different file `/usr/lib/xorg/protocol-precise.txt', not allowed

Try the below commands,

sudo mv /usr/lib/xorg/protocol-precise.txt /usr/lib/xorg/protocol-precise.txt.bak
sudo apt-get -f install

The above commands rename that text file protocol-precise.txt to protocol-precise.txt.bak and fixes the dependencies.


How do you change the backup location on Deja-Dup?

If you open "Local Folder" there is a button with "Choose directory" (or similar, my OS language is German so I'm not exactly sure what it is in the English version). If you click on this button you can choose any directory to be the saving location on any drive, including attached USB drives, on your machine


infinite blinking cursor at top lefr corner of the screen after booting

It sounds like the Ubuntu installer wasn't able to complete the installation due to the power outage. The solution is simple: just boot into the USB installer and start the install process over again.


Cannot access drive mounted by sshfs using Ubuntu file manager

Maybe try -o allow_other to allow users other than the mounter to access.

Even better, you don't need to be root to use sshfs, so you can simply create the directory and mount the remote directory as yourself (but with root@serverB).

From a security perspective, you need to establish a connection as root@serverB (which you do already), and then you need at least execute permission on the mount directory and access to the mount contents itself.


Ubuntu 16.04 LTS What Job Updates /boot/grub/grub.cfg

It sounds like the unattended-upgrades may be running. See related post.

Also check /var/log/unattended-upgrades for activity from that tool.

See  /var/log/apt/history.log for a history of package upgrades your system.


Ubuntu stops and says failed to start user manager for uid 120

Boot into Recovery Mode...

enter the GRUB menu
choose "Advanced Options"
choose the newest kernel ending with "(recovery mode)"
choose "Root Access"
enter the root password if required
enter sudo mount -o remount,rw /

Based on whether you installed the All-Open or Pro components, run one of the following commands:

Use this for All-Open components...

$ amdgpu-uninstall

Use this for Pro components...

$ amdgpu-pro-uninstall

Then:

$ reboot

source: http://amdgpu-install.readthedocs.io/


You may be having the same issue as this post (I provided an answer there).

Note that I had to use a working windows machine to download the needed files to a thumb-drive so I could copy them into my Linux machine.

In my answer there's a link to another posting which can take you to the correct place to download the needed files.


Find, rename and copy files to a new directory

It's easy! You can count in bash and produce/read a list of filenames:

declare -i num=0
destination="$PWD" # set to destination of files
find . -type f -name 'ycut2.gif` -print | sort | while read fn ; do
    num=$(($num + 1 ))
# following line assumes no more than 99 files
    j=printf "%02d" $num
    cp "$fn" "$destination/$j.gif"
done


Make a new USB boot using Unetbootin or LiLiUSB, both for Windows. Your USB media is corrupted.


How can I get Deja-Dup to use my "Skydrive" account instead of Ubuntu One?

To be able to do that check Here.

Its for 11.10, but I tried it, and it works on 12.04


how to install specific version of minetest?

Then let's download 0.4.16 from official bionic repository by commands below
cd ~/Downloads
wget http://archive.ubuntu.com/ubuntu/pool/main/l/leveldb/libleveldb1v5_1.20-2_amd64.deb
sudo apt-get install ./libleveldb1v5_1.20-2_amd64.deb

wget http://archive.ubuntu.com/ubuntu/pool/universe/m/minetest/minetest-data_0.4.16+repack-4_all.deb
sudo apt-get install ./minetest-data_0.4.16+repack-4_all.deb

wget http://archive.ubuntu.com/ubuntu/pool/universe/m/minetest/minetest_0.4.16+repack-4_amd64.deb
sudo apt-get install ./minetest_0.4.16+repack-4_amd64.deb

and pin/lock their versions by single long command:
cat <<EOF | sudo tee /etc/apt/preferences.d/pin-minetest
Package: minetest-data
Pin: version 0.4.16+repack-4
Pin-Priority: 1337

Package: minetest
Pin: version 0.4.16+repack-4
Pin-Priority: 1337
EOF

to prevent their upgrade.


fixing broken config/permissions on a clean 11.10 install with an old home dir

Found the issue!

It seems that it was taking took long for console kit to load, which in turn broke permissions for everything else.  I had an .ecryptfs folder that seemed to be the reason it took too long to load, and deleting that fixed everything else.


Automatically change Sound Input Output device

There is pulseaudio module-switch-on-connect and module-switch-on-port-available that enable automatic switching of an audio device on connection. See with the following command if any of these modules is already loaded:
pactl list short modules

If not, then test if you can make automatic switching work by issuing one or both of the following commmands in a terminal:
pactl load-module module-switch-on-connect
pactl load-module module-switch-on-port-available

On success add one or both of the following lines to your /etc/pulse/default.pa
load-module module-switch-on-connect
load-module module-switch-on-port-available

This will then always load these modules on every login, resp. restart of the pulseaudio daemon.
Please note that local user settings in ~/.config/pulse/default.pa override system-wide setting. If you have such a local file you will enter the above commands there.
If it still not works you may have conflicting settings in such a local default.pa. It then may worth to (temporarily) rename this file followed by a restart of the Pulseaudio server before trying above again:
mv ~/.config/pulse/default.pa ~/.config/pulse/default.pa.old
pulseaudio -k


What does Ubuntu use for creating cloud-images?

You can find the code for building all the cloud images here:

https://code.launchpad.net/~ubuntu-core-dev/livecd-rootfs/trunk

See also:

How are the Official Ubuntu Vagrant boxes built and published to Atlas?


Ubuntu One: file modified dates versus synchronization date

There is no trick. Ubuntu One does not synchronize file creation/modification/access times, nor file permissions.

When downloading files to a new system, the file will have the creation/modification time of when it was written to disk on that system.


ECS is a relatively new service, perhaps the version that apt-get gives us doesn't have that option yet. After apt-get installing awscli on ubuntu, the version is 1.2.9, whereas the one I downloaded from the site onto my machine is 1.7.36.....

The aws ecs command works from my command prompt after I manually downloaded the AWS cli, so it's definitely there, just not in this version.


I/o disk error when resume from hibernate/suspend on battery power Notebook

Ubuntu have problems with  n-trig driver display maybe this cause the problem...disable it and try again...
is this the only one issue?  what about the graphic display issue?  ati x1250 shows strange lines on the top panel

google translate :P


Unable to perform DNS queries over IPv6 from laptop

Nevermind, this is because nothing is listening locally for dns requests over ipv6, see this github thread: https://github.com/systemd/systemd/issues/12159


You have to remove locally compiled libraries by
sudo rm /usr/local/lib/libcdio_paranoia.so.2
sudo rm /usr/local/lib/libcdio_cdda.so.2

and then retry.


Probably something is wrong with your /etc/apt/sources.list document. You should remove your PPAs, because it seems that someting is wrong with them. Open a terminal (Strg + Alt + T) and type sudo nano /etc/apt/sources.list. After you've entered your password, you can see all the PPAs and official repositorys.
The standard sources.list file looks like this:

deb http://de.archive.ubuntu.com/ubuntu quantal main restricted universe multiverse
#deb-src http://de.archive.ubuntu.com/ubuntu quantal main restricted universe multiverse

deb http://de.archive.ubuntu.com/ubuntu quantal-updates main restricted universe multiverse
#deb-src http://de.archive.ubuntu.com/ubuntu quantal-updates main restricted universe multiverse

deb http://de.archive.ubuntu.com/ubuntu quantal-security main restricted universe multiverse
#deb-src http://de.archive.ubuntu.com/ubuntu quantal-security main restricted universe multiverse

deb http://de.archive.ubuntu.com/ubuntu quantal-backports main restricted universe multiverse
#deb-src http://de.archive.ubuntu.com/ubuntu quantal-backports main restricted universe multiverse

So, delete all the entries and paste the repositorys above into the file. Then press Strg + O for saving changes and than Strg + X for exiting.

Please remark, that all your manually added PPAs are deleted in this way. But you can add them later again, if you have updated your programs.


What is the gksudo "lock taken...exiting" warning and how do I resolve it?

You need to remove the lock for gksudo to work.

But instead of removing it, you can just rename it to something else.

Just try the following:

sudo mv  ~/.gksu.lock ~/.gksu.lock.old


Wired internet speed is slow in Ubuntu 12.04

If you are having slow internet speeds when downloading packages you can do this:

1)Open the software center

2)Go to Edit>Software Sources

3)Under "Ubuntu Software", click the dropdown list labeled "Download from".

4)Click "Other".

5)Now click "Select Best Server".

It will run tests and come up with the server that is right for your location. If it is an issue with slow browsing speeds not related to the Ubuntu servers make sure your browser is up to date.


I've struggled the same. On Gnome, I can successfully suspend by running from terminal:

$ sudo pm-suspend

cf


Ubuntu 13.04, how to upgrade to GNOME 3.8.x

According to apt-cache policy the current version of Gnome in the repositories is 3.8:

user@host:~$ apt-cache policy gnome
gnome:
  Installed: (none)
  Candidate: 1:3.8+4ubuntu1
  Version table:
     1:3.8+4ubuntu1 0
        500 http://us.archive.ubuntu.com/ubuntu/ saucy/universe amd64 Packages

So you should be able to upgrade just fine currently.

Note I'm running 13.10, but it should be the same in 13.04. Run apt-cache policy gnome to double check


How can I add a custom item to the nautilus context menu, but NOT in a sub-menu?

You can do it with nautilus-actions. Launch nautilus-actions-config-tool and go to Edit > Preferences > uncheck "Create a root Nautilus Actions menu"  and bottom of the first tab. -- This affects all actions.

Also, in the left panel the entries (actions) can be grouped as sub-menus. Create your actions (New action'), then create a  'New menu' with right-click or under 'File' for each action category, and then drag&drop your actions of that category on it.

Which gives this:


You have set the option Show hidden and backup files in the Edit -> Prefererences. Just clear the checkbox and the hidden files will stay hidden after you re-open the file manager.


Running keepalived with vrrp in unprivileged lxc container

Containers aren't allowed to load modules as they share kernel with the host machine. Once you load module on your hardware node, it will become available on all the containers. The same rule is for OpenVZ virtualization.


That bluetooth device needs a proprietary driver due to its design and it doesn't seem that Ralink wants to release it to the kernel developers
https://bugs.launchpad.net/ubuntu/+source/linux-lts-trusty/+bug/1355096


Install gdm3 - 3.28.2-2ubuntu1 on ubuntu 18.04

Version 3.28.2-2ubuntu1 is in Cosmic. A fixed version for Bionic has not yet been released.

A tentative fix (3.28.2-0ubuntu1.2) is now in bionic-proposed; install at your own risk


Does the Ubuntu website use customary or SI definitions?

RAM is always declared in octal values. There is no RAM that is manufactured to a specification of 1000 bytes == 1 KB. RAM is always marketed as GB, and is always 1024 bytes == 1 KB.

The use of GiB versus GB is primarily for storage, where Hard Drive and other storage device manufacturers have generally always used 1000 bytes == 1 KB, and to make the difference clear in the user interface.

If you believe for some reason that the web site is inaccurate, there is a link at the bottom of every page for Report a bug on this site, where you can report the issue.


I fixed this issue by setting the user and group of the /var/lib/lightdm directory back to lightdm.


This might help: https://wiki.ubuntu.com/UbuntuOne/FAQ/WhyArentMyContactsInEvolutionSyncing


Is there any facial recognition software for logging in on Ubuntu 14.04/10

You can try this new ppa put together with the github version of pam-face-authentication which should be up to date with newer dependencies:

https://launchpad.net/~doctormo/+archive/ubuntu/opencv

Comment here if the package works for you or if it fails. I'll update this post with more install details if more people confirm.


Is there any way to make the cut command read the last field only?

No cut can't do that. You could use two rev commands, like

echo 'foo bar baz' | rev | cut -d' ' -f1 | rev

but it's usually easier to use awk:

echo 'foo bar baz' | awk '{print $(NF)}'


Since the bug you are reffering to is more than a year old and probably doesn't apply to 14.04 I would suggest to file a new bug report with ubuntu-bug from a terminal and provide as much detail as possible when the crash happens using these steps: https://help.ubuntu.com/community/ReportingBugs#Reporting_an_application_crash_in_the_stable_release


That is interesting that the / actually allows 777 permissions to be set on it.  The / folder should not have 777 permissions, as this means that any user logged into the system can create files and folders at the / root level.  I have tested this in a VM and you CANNOT delete any of the folders or files that are not 777 without being sudo, root or the owner.  The access permissions are still followed, like trying to access the /root folder itself would give you permission denied. However, that being said, you could still move the /root folder to /root.old creating little havoc.

To fix this you can run sudo chmod 755 / to change permissions to what they should be.  You can also run sudo chown root:root / just to make sure that it is owned by root itself.  DO NOT run any of those commands with -R as this will change all files and folders in the partition to match permissions and ownership.

Hope this helps!


As long as you're plan is to completely replace Ubuntu with Windows 7, I would boot up the computer with the Ubuntu live CD (or USB).
Then run GParted and delete all your partitions. Once that's done, run your Windows installation. You should be good to go.


Some issues with Anonsurf and Tor on 18.04 LTS

I have ported ParrotSec/anonsurf to Ubuntu 18.04 LTS. You can download the ported version here moonchitta/anonsurf-ubuntu.
Clone it with

git clone https://github.com/moonchitta/anonsurf-ubuntu.git

Make sure you have tor installed, if not then install it with

sudo apt-get install tor

After installing tor, cd into the directory and execute

sudo make install

and then run it like

sudo anonsurf start

hope it will help you.


How do I set Terminal as part of my wallpaper?

Try terminal applet for screenlets

or Guake terminal


Data lost after attempting to reinstall Ubuntu without losing data present on home folder

Most likely the old data is preserved in the old /home/(username) folder, while Ubuntu created a new home folder to ensure that settings still in the old /home/(username) won't conflict with the new installation.  You should be able to use a file browser (such as dolphin) to browse one level up from your user home folder, and find the other folder there, with your old data safe inside.


In order to get your custom cursor to work with all applications do:

Download a cursor theme.
Open Gnome Tweak Tool and change the cursor theme.
Open a Terminal.
Run this command:

sudo update-alternatives --config x-cursor-theme

Select the number corresponding to your choice
Log out.
Log back in.

You can see a video tutorial on YouTube.


I found it out

sudo nano /etc/mongodb.conf and

add auth = true
add an IP you want to give access to to 'bind_ip' or change the value to '0.0.0.0' to give access to everyone (you obviously have to create admin user before that)


Ubuntu 12.04 questionable RAM usage, mouse lags, windows fade slowly and programs hang...after a few hours things return to normal

In my case adding pcie_aspm=force to the Grub config didn't help. It seems that the poor graphic performance is related to this bug: Poor performance on Intel® 965GM x86/MMX/SSE2. If anyone with Intel 965GM experiences the same problems please go and vote for it  (see how to vote and make sure you're logged in), hopefully it will get fixed sooner.


Really slow upload/cast compared to smartphones and other laptops in the same network

I had the same problem on my Lenovo P53. Wifi was working, but very slowly. I was using the backport-iwlwifi-dkms driver. Deinstalling it with sudo apt-get purge backport-iwlwifi-dkms and rebooting solved it for me.

Be sure to be close to a ethernet cable in case that doesn't work as expected and you have to reinstall the driver.


Do you mean you want Rhythmbox to display onto the remote computer's screen? The screen onto which a GUI application is displayed is indicated by the DISPLAY environment variable. When you run ssh -X, DISPLAY is set to a value that indicates that display requests must be forwarded over the SSH connection. To make the application display on the remote computer's screen, set DISPLAY to the value :0.

ssh username@example.com 'DISPLAY=:0 rhythmbox &'

There's one more hurdle: when an application connects to an X display, it needs to provide a sort of password called a cookie. The cookie is generated each time the X server starts. Ubuntu stores the cookie in a file with a randomly generated name. The easiest way to find the cookie is to store it in a well-known file name when the X server starts. On Ubuntu, add this code to your ~/.profile:

case $DISPLAY:$XAUTHORITY in
  :*:?*)
    # DISPLAY is set and points to a local display, and XAUTHORITY is
    # set, so merge the contents of `$XAUTHORITY` into ~/.Xauthority.
    XAUTHORITY=~/.Xauthority xauth merge "$XAUTHORITY";;
esac

For more background, see ssh DISPLAY variable.

Or did you mean you never ever want to see the Rhythmbox window? If so, make it connect to a virtual X server, xvfb . Start the virtual X server, then tell Rhythmbox to connect to it.

ssh username@example.com 'Xvfb :1 -screen 0 800x600x8 & sleep 1; DISPLAY=:1 rhythmbox &'


PATH variable in different terminal windows

When you call source ~/.bashrc you reload your ~/.bashrc configuration only for that current terminal session. You have to do it for all other existing terminal sessions as well if you want to reload your ~/.bashrc


This error may occour when the module is not loaded.
Even if you don't use Arch Linux, you can still read this: https://wiki.archlinux.org/index.php/VirtualBox#Load_the_VirtualBox_kernel_modules

So, just try:

sudo modprobe vboxdrv

or reboot your computer.


Why is Dash to panel in 17.10 replaced by Ubuntu Dock at each logon?

Just found the culprit... It's the "Extensions" extension from extensions.gnome.org. If it's active, for some reason it restores the previous choice of dock after each logoff. Switched it off and I can now stay with the dock I choose.


What is best practices for upgrading for Rails 3?

Well if your current system working perfectly, what is the point of upgrading? For your question sometimes upgrading may cause some errors. But it depends on your system. Wait some time before upgrading to the newer system. Then may be you can find if there are any bugs. You can boot from older version. My opinion is stay on your current system.
Thanks.!


Problem solved. Sorry to be a numpty. It was so simple in the end, I never thought of it. Thanks to Serg's comment, it got me thinking. Somehow the Desktop had been switched to Gnome during the upgrade. I simply switched back to Ubuntu on startup and it works fine. Thanks Serg.


Is it possible to install ubuntu server (12.04) on gpt disk (3TB) and boot from it

Two types of firmware are in common use today, and the answer is slightly different for each of them:

Basic Input/Output System (BIOS) -- This type of firmware is as old as the IBM PC. It's very rudimentary; its boot process is to read the first sector from the hard disk and run the code it finds there. If that code is a boot loader that understands GPT, then a BIOS can boot from a GPT disk. There is a caveat, though: Some BIOSes (or some EFIs in BIOS compatibility mode; see the next point) flake out in one way or another when they see GPT disks. It's usually possible to work around such problems, but they can be difficult to deal with if you don't understand them. See my page on the subject for more details. Also, if you use GRUB 2 as your boot loader (which Ubuntu does by default), you'll need a BIOS Boot Partition to boot from a GPT disk. The Ubuntu installer sets this up by default, but you'll need to do it yourself if you pre-partition your disks.
Extensible Firmware Interface (EFI) -- This type of firmware (more recent versions of which are known as the Unified EFI or UEFI) is a replacement for the BIOS. It boots in an entirely different way from BIOS, storing boot loaders and related files on an EFI System Partition (ESP). GPT is part of the EFI specification, so of course EFI-booting from a GPT disk is not a problem. Most modern EFIs have a BIOS compatibility layer, so you can boot a BIOS-mode boot loader on most modern PCs, but these often have GPT quirks, as noted earlier.

LVM is not a problem with either method of booting, although if you use LVM, you'll do well to create a separate /boot partition outside of the LVM. You can use LVM with either MBR or GPT disks.

The term "extended partition," BTW, is meaningful only with the older Master Boot Record (MBR) partitioning scheme. An extended partition holds logical partitions, and is a workaround for the 4-partition limit of MBR's primary partition table. GPT lacks this limit and so has no need of either extended or logical partitions. In your use, I think you didn't mean extended partitions, but rather an LVM volume group that holds logical volumes. A logical volume is much more flexible than a partition, but requires more complex tools to manage.


Comparing your cups.conf file, I only see a few differences:

You've replaced Port 631 by Listen localhost:631 to prevent remote administration
You've removed Allow @LOCAL three times:

 DefaultAuthType Basic
 <Location />
   Order allow,deny
-  Allow @LOCAL
 </Location>
 <Location /admin>
   Order allow,deny
-  Allow @LOCAL
 </Location>
 <Location /admin/conf>
   AuthType Default
   Require user @SYSTEM
   Order allow,deny
-  Allow @LOCAL
 </Location>

Re-add those lines or you'll be unable to open CUPS. After adding yourself to the lpadmin group, you need to restart CUPS due to the way groups work. That can be done with:

sudo restart cups


Home isn't a real directory: it's just what the file manager (nautilus) uses as a shorthand for the user's home directory, otherwise known in the shell as $HOME.

It usually expands to /home/username (where username is replaced by your actual login name) but you should confirm by running echo $HOME in a terminal.


"Permission denied" when download from script(ruby) file

Try the below command,

sudo chmod a+rw -R

After this run,

.rvm

Then try to install ruby. Hope this helps.


Version of Ubuntu for Fujitsu AH502 Lifebook?

To answer in short: AMD64 (aka x86_64) refers to 64-bit architecture used by AMD as well as Intel (and VIA and few others too). It's called AMD64 only because AMD was first to come up with a 64-bit CPU architecture.
Similarly, Intel x86 refers to 32-bit implementations of Intel & AMD equally.

What it implies for you: You can (and should) use the 64-bit version you downloaded even if the machine's using an Intel CPU. I'm using the same version on an Intel laptop.

For further info: check this Wikipedia page


My notebooks integrated webcam isn't working in ubuntu 16.04

I finally figured it out. I had a newer version of the linux kernel installed that didn't had some modules. So I just returned to a previous version through my dual boot menu and it fixed it.


Kdenlive and Blender both can't use GPU hardware acceleration

Reading your situation I would assume that you only have the one graphics card in your system. You will need a 2nd capable card.

One to use for your main display AND
another one for GPU Compute.(no display should be attached to the 2nd card.)
once your system detects both cards you should be able to launch Blender and select the proper render option for the 2nd card.

As for KDENLive if it uses a 2nd GPU to compute you may have issues running both programs simultaneously ( I have not been able to test this out since the last build I tried basically locked up the program.) most NLEs (like LightWorks, and from what I seen with ShotCut) uses the GPU that also displays on your monitor so you may not need to worry much on that front...

Hope this steers you in the right direction.


Package 'dkms' has no installation candidate

Adding repository main using:
sudo apt-add-repository main
fixed the problem.


Samba network discovery for NetBIOS hosts has issues as described here: https://bugs.launchpad.net/ubuntu/+source/gvfs/+bug/1778322?comments=all

The Good News: Linux and MacOS machines do not have to use NetBIOS for host discovery. It can be replaced with Avahi.

Make sure avahi-daemon is installed on the Pi:

sudo apt install avahi-daemon

Make sure it's running:

sudo service avahi-daemon status

Create a file on the Pi at: /etc/avahi/services/samba.service

With this content:

<?xml version="1.0" standalone='no'?>
<!DOCTYPE service-group SYSTEM "avahi-service.dtd">
<service-group>
   <name replace-wildcards="yes">%h SMB</name> ## Display Name
   <service>
       <type>_smb._tcp</type>
       <port>445</port>
   </service>
</service-group>

You may need to restart the daemon: sudo service avahi-daemon restart

Nemo will show the Pi under Network but not under Windows Network since it's not using the Windows discovery protocol.


When I trying to install Ubuntu alongside with Windows 7 restart and wont install

Try doing this manually, select 'something else' during install and create a partition to install into.

So long as you ignore any NTFS partition you wont hurt Windows, it's not as scary as it first looks. Maybe this will get you further along.

How to use manual partitioning during installation?


As drake01 has said, if you use the -t flag, you need to specify the filesystem type after it. See man mount for details.

However, you usually do not need to specify -t or the filesystem type. mount should be able to infer the filesystem type, and when it cannot, usually that means you are mounting it incorrectly or there's something wrong with the partition.

Furthermore, you generally must run mount as root.

So you could just use:

sudo mount /dev/sda12

But that, too, will be insufficient unless /dev/sda12 is listed in /etc/fstab. Otherwise, you must mount it, specifying the mount point.

So, if you wanted a mount point of /media/Foo, first you would have to create it (if it's not already there):

sudo mkdir /media/Foo

Then you'd mount the drive there, specifying that as the mount point:

sudo mount /dev/sda12 /media/Foo

You can see what's mounted by running mount with no arguments:

mount

Once mounted, you can unmount it with the umount command, passing the device node name or the mount point name:

sudo umount /dev/sda12

sudo umount /media/Foo

You may prefer to mount this volume without running any commands as root, and without having to create or specify a mount point. You can accomplish that with a dynamic mount. The mount point is created on-the-fly and is named the same as the volume name (unless there is no volume name, then usually it's the partition's UUID).

Dynamic mounting in Ubuntu is done with udisks. You can invoke it explicitly:

udisks --mount /dev/sda12

Or you can click on the volume in a file manager like Nautilus, and the appropriate udisks command will be invoked automatically. (This is especially helpful if you don't know the device name but could identify the partition's volume name in a list.)

To unmount a partition that is mounted with udisks:

udisks --unmount /dev/sda12

Or you can still unmount it directly as root, if you wish:

sudo umount /dev/sda12


Problems on setting up rails server (4.2.4) on Ubuntu 14.04 LTS

I just did this on my Ubuntu 14.04.3 machine:

cd ~
rails new test-app
cd test-app
rails server

...and it starts right up. So it seems to me that you are having a problem with you app. Please try what I did and see how it goes.

Also, I have had nothing but trouble with rvm on Ubuntu. So, I use rbenv (https://github.com/sstephenson/rbenv).

To install rbenv, do:

# remove old rvm
sudo apt-get remove rbenv ruby-bundler ruby-rvm

# common rbenv and rails dependencies, generally good things to have
sudo apt-get install zlib1g-dev openssl libreadline-dev git-core libnotify-dev \
                     libc6-dev libssl-dev libmysql++-dev libsqlite3-dev \
                     make build-essential libssl-dev libreadline6-dev \
                     libyaml-dev curl

# rbenv installer
curl https://raw.githubusercontent.com/fesplugas/rbenv-installer/master/bin/rbenv-installer | bash

# Add rbenv init to .bashrc
echo 'export RBENV_ROOT="$HOME/.rbenv"' >> ~/.bashrc
echo 'export PATH="$HOME/.rbenv/bin:$PATH"' >> ~/.bashrc
echo 'if which rbenv > /dev/null; then eval "$(rbenv init -)"; fi' >> ~/.bashrc
exec $SHELL

# Install ruby (this takes many minutes ...~15-ish ...maybe 30 depending on your system)
rbenv install 2.2.2

# Defining which ruby version to use globally
rbenv global 2.2.2

Also, Rails development on Ubuntu would be helped by Prax (https://github.com/ysbaddaden/prax), it's like Pow but for Linux and it's written in pure Ruby.

EDIT:

I tried the pinteresting app and it too started up fine for me:

# I had to install a 2.0.0 version of Ruby
rbenv install 2.0.0-p645

cd ~
git clone https://github.com/onemonthrails/pinteresting
cd pinteresting
echo '2.0.0-p645' > .ruby-version
bundle install
rake db:migrate
rails server


KDE Plasma crash after a few seconds (Kubuntu 18.04)

I found the (somewhat surprising) solution: Blocked print jobs in CUPS killed the complete desktop environment! So, if someone faces the same problem:

Go to the CUPS server or to the print manager and remove all print jobs that have stopped or
run lprm -
Check if all print jobs could be removed! In my case, some jobs could not be removed. They belonged to a printer with a suspicious configuration, so in the end I simply removed the entire printer.

Hope it helps!


How do I install these printing and mail related utilities?

In order to use lp, lpstat and cancel, you need to install and configure a printer.

In the process of installing the printer, you're going to install cups-client, which contains these utilities.

The mail program is in mailutils

To install both of these, type

sudo apt-get install cups-client
sudo apt-get install mailutils

Afterwards, you may want to

set up a Print server
set up a Mail server


Compiling C++ code raising "no input files" fatal error?

You need to have the code file (in this case helloworld.cpp) in your current working directory. If the code file is in a different directory, you need to specify where in the command. For example

g++ some/other/folder/helloworld.cpp -o helloworld.o


Switch to using rdiff-backup for backups of / instead of rsync?

There is a good example how to use rdiff to back up the root partition:
http://manual.aptosid.com/en/sys-admin-rdiff-en.htm

Personally I use the following syntax to back up:

rdiff-backup --exclude-sockets --exclude '/media/*/*' --exclude '/mnt/*' --exclude '/proc/*' --exclude '/sys/*' --exclude '/tmp/*' / {backup-dest-dir}

And the following syntax to restore:
rdiff-backup -r now  {backup-dest-dir} {restore-dir}

You have to run rdiff-backup as root to remain permissions, ownership, groups, modified times, etc. I can ensure rdiff-backup takes care of all your requirements.

Used it today to restore the root partition after a failed upgrade from Ubuntu 8.04.4 --> 10.04.4 --> 12.04 (dev).


ubuntu 14 hibernate does not appear clear to me

To test if your system will hibernate properly, open a terminal and enter the command

sudo pm-hibernate

If the system properly turns off, and comes back on with out problems, then you can follow the instructions here to enable hibernation on your system.


Clients Not Working With Offline Ubuntu 16.04 Repository

Well, after taking a very conservative approach, I started hacking on the internal repo.  My problem was I had linked the wrong path to http://inside-server/ubuntu.

The apt-mirror command clones more that what is needed to host a mirror.  The actual path is /mirror/ubuntu.archive.com/ubuntu.


It seems that the kernel itself might be ok but somewhere in the benchmark tool (Disks) of ubuntu could be the issue.
Solution (work-around): I created a directory in the disk to be tested and then terminal into the directory and ran two commands on it. The first commands creates a temp file (4GB in size) and tests the write speed of the disk and the second command reads that file and tests the read speed.
The commands: -write: dd if=/dev/zero of=tempfile bs=1M count=4096 conv=fdatasync,notrunc status=progress oflag=direct -read: dd if=tempfile of=/dev/null bs=1M count=4096 status=progress iflag=direct
Here is my result:


Can't access Windows 8 after Ubuntu install and after Boot-repair

The easiest way to fix this would be to boot into windows recovery mode [via Windows Disk ] and startstartup repair.This will automatically install windows boot manager( Will also fix your Boot configuration data) which will also list Ubuntu OS to boot from on your next restart.


How can I install Indicator Synapse on Ubuntu 16.04?

Use the following command on your terminal. Then It will be OK.

sudo add-apt-repository ppa:noobslab/apps
sudo apt-get update
sudo apt-get install indicator-synapse

If you face problem with ubuntu 16.04, Then follow the following instruction:

System Settings > Software&Updates > Other Software > find and click noobslab/apps repository > Edit > change Distrbution value to "trusty". Then sudo apt-get update and sudo apt-get install indicator-synapse. That's all.

You can also check this URL. Hope you will find the solution.

https://gist.github.com/brenopolanski/cb56125da4fede7a8abf