From the GUI:

Select power symbol in upper right of Fossa Desktop screen
Select "Power Off..."
Select "Power Off"

From a command line (terminal) try:
sudo shutdown -h now
If neither of these power down your computer, it is most likely an issue with your Laptop/PC hardware configuration (sometimes referred to, quite inaccurately, as BIOS config).  Refer to your manufacturers documentation on how to enter and navigate the hardware setup; look for "power management" options.  Failing everything, most setup utilities have a "Revert to Factory Default" function - this is an option of last resort: it may solve your problem but it could just as easily leave your system unbootable!
Addition:
There are some Alienware systems that suffer from a kernel panic on shutdown due to an dw_i2c driver. See https://unix.stackexchange.com/questions/423797/how-do-i-disable-i2c-designware-support-when-its-not-built-as-a-module/446913#446913 for details.  For this situation,

Add "initcall_blacklist=dw_i2c_init_driver" to the "GRUB_CMDLINE_LINUX_DEFAULT" in /etc/default/grub
execute sudo update-grub
Reboot: sudo shutdown -r now
Shutdown: sudo shutdown -h now


You really do not need Wine. Follow these steps:

download your file FinalFantasyVAdvanceEditor_v1-0.zip
Unzip it with unzip FinalFantasyVAdvanceEditor_v1-0.zip
Install JRE with sudo apt-get install default-jre
Run it directly as java -jar FFVAEditor.exe


Are internet connection passwords available from some location in /home?

Your Internet connection login/password, etc, are stored in /etc/NetworkManager/system-connections/... So, if you did a fresh install (rather than an upgrade) then you wiped those files out.

Did you copy them out to your /home/yourUserName/someplace? If not, then those are permanently gone. You will have to create them anew.

Bottomline: I don't think there's any way to (easily) recover that info now.


New HDD formating on Ext4 root permission

One formatted in ext3/4 will be treated as an extension of the base root file structure. To resolve your problem with ext2/3/4 devices:

sudo chmod -R a+rw /media/name_of_your_80gb_hdd

This will have owner = root but allow everyone to have access.


Copying files to var/lib/tomcat7/webapps/ROOT

To run a command that requiere root privileges you can use 'sudo' in front on your command, ie:

> sudo cp /home/myhome/file.txt /other/destiny/file.txt

Then, to change the owner:

> sudo chown myuser /directory/file.txt

You can find basic bash commands here


PulseAudio fails to set card profile to 'a2dp_sink'. How can I see the logs and figure out whats wrong?

In order to allow your system to be detected as an A2DP sink (e.g. to play music from your phone via your computer speakers), add Enable=Source,Sink,Media,Socket under [General] in /etc/bluetooth/audio.conf.
After doing this, restart the bluetooth daemon
systemctl restart bluetooth

Connect you headphone device
bluetoothctl
connect <MAC>

Check your card and set profile
pactl list cards short
pacmd set-card-profile <index> <profile>


The command apt-get source pulseaudio will download the current source package files and extract them automatically for you. You will find the rules file in the debian directory inside the newly created source directory named after the package, here is how that looks on my installation:

livewire@za20:~/Downloads$ apt-get source pulseaudio
Reading package lists... Done
Building dependency tree
Reading state information... Done
NOTICE: 'pulseaudio' packaging is maintained in the 'Bzr' version control system at:
http://bazaar.launchpad.net/~ubuntu-audio-dev/pulseaudio/ubuntu
Please use:
bzr branch http://bazaar.launchpad.net/~ubuntu-audio-dev/pulseaudio/ubuntu
to retrieve the latest (possibly unreleased) updates to the package.
Need to get 1.468 kB of source archives.
Get:1 http://archive.ubuntu.com/ubuntu/ trusty/main pulseaudio 1:4.0-0ubuntu11 (dsc) [4.246 B]
Get:2 http://archive.ubuntu.com/ubuntu/ trusty/main pulseaudio 1:4.0-0ubuntu11 (tar) [1.392 kB]
Get:3 http://archive.ubuntu.com/ubuntu/ trusty/main pulseaudio 1:4.0-0ubuntu11 (diff) [71,8 kB]
Fetched 1.468 kB in 3s (455 kB/s)
gpgv: Signature made Fr 04 Apr 2014 09:40:46 CEST using RSA key ID 9B1A3456
gpgv: Can't check signature: public key not found
dpkg-source: warning: failed to verify signature on ./pulseaudio_4.0-0ubuntu11.dsc
dpkg-source: info: extracting pulseaudio in pulseaudio-4.0
dpkg-source: info: unpacking pulseaudio_4.0.orig.tar.xz
dpkg-source: info: unpacking pulseaudio_4.0-0ubuntu11.debian.tar.xz
dpkg-source: info: applying 0003-esd-honour-system-pulseaudio.patch
dpkg-source: info: applying 0005-dont-load-cork-music-on-phone.patch
dpkg-source: info: applying 0006-load-module-x11-bell.patch
dpkg-source: info: applying 0016-nodisplay-autostart.patch
dpkg-source: info: applying 0020-stream-Return-error-in-case-a-client-peeks-to-early.patch
dpkg-source: info: applying 0022-inotify-wrapper-Quit-daemon-if-pid-file-is-removed.patch
dpkg-source: info: applying 0023-fixing_snd_mixer_poll_descriptors_count_when_zero.patch
dpkg-source: info: applying 0101-alsa-ucm-Make-combination-ports-have-lower-priority.patch
dpkg-source: info: applying 0102-combine-Fix-crash-in-output-freeing.patch
dpkg-source: info: applying 0103-resampler-Fix-peaks-resampler-s-channel-handling.patch
dpkg-source: info: applying 0104-default-system.pa-Do-not-load-module-dbus-protocol.patch
dpkg-source: info: applying 0105-sink-source-Initialize-port-before-fixate-hook-fixes.patch
dpkg-source: info: applying 0106-module-switch-on-port-available-Don-t-switch-profile.patch
dpkg-source: info: applying 0201-ALSA-Add-extcon-Android-switch-jack-detection.patch
dpkg-source: info: applying 0202-dont-probe-ucm.patch
dpkg-source: info: applying 0203-card-Add-hook-before-profile-changes.patch
dpkg-source: info: applying 0204-Add-module-to-talk-to-the-Android-audio-hal-to-set-u.patch
dpkg-source: info: applying 0205-suspend-on-idle-ensure-we-still-time-out-if-a-stream-remains-corked.patch
livewire@za20:~/Downloads$ ll pulseaudio-4.0/debian/rules
-rwxrwxr-x 1 livewire livewire 3346 Apr   4  2014 pulseaudio-4.0/debian/rules*

So you can find the file in pulseaudio-4.0/debian/rules the version number may be different depending on the Ubuntu release you are using.


Wifi configuration after Ubuntu Server installation

Step 1: In the command line interface run the command

cat /etc/wpa_supplicant.conf

Step 2: At  the end of the file, type this lines

ctrl_interface=DIR=/var/run/wpa_supplicant GROUP=netdev
update_config=1
    network={
         ssid="Your network name/SSID"
         psk="Your WPA/WPA2 security key"
         key_mgmt=WPA-PSK
    }

Example: If the SSID is rocket and password is 12345678
you would add

ctrl_interface=DIR=/var/run/wpa_supplicant GROUP=netdev
update_config=1
    network={
         ssid="rocket"
         psk="12345678"
         key_mgmt=WPA-PSK
    }


How to release Ctrl+Alt+A keyboard shortcut so it can be used for KeePassX?

Open Global Shortcuts
Under System Services, look for KWin
The first entry for the KWin section should be Activate Window Demanding Attention
Disable it or change the shortcut to something else
Press Apply

These instructions were tested on KDE Plastma 5.19.4.


gnome-flashback panels not starting in ubuntu 14.04

Delete $HOME/.local/share/applications/gnome-panel.desktop

For some reason the old system copied its gnome-panel.desktop to your own $XDG_DATA_HOME (by default on .local/share). After the upgrade, /usr/share/applications/gnome-panel.desktop (belonging to gnome-panel package) was updated, but not the copy, which still has the old contents and is thus shadowing the global file (per the XDG Base Directory Specification).

As the old file is incompatible with the new version (which seems a bug), gnome-panel is not started.

Just by deleting this copy, the /usr/share instance will be found, properly launching  gnome-panel without having to run it by other means.

In case you prefer to fix the existing file instead of removing it (although there's nothing important there), open with a text editor and:

Change OnlyShowIn=GNOME to OnlyShowIn=GNOME;Unity;
Remove the StartupNotify=true line

Save and restart the session.


Service --status-all --> what does the column with [ ? ],[ + ], and [ - ] mean?

Well those are just exit codes. After something has done running, it can return an 8-bit integer (0-255) to indicate how it exited.

Zero (which is implied if nothing is returned) means the application got to the end of what it was supposed to do and exited naturally.
Non-zero codes (1-255) can mean whatever the application wants. The man page (man <command>) will usually show you what these codes mean.

In terms of the question, don't overthink it:

+ means it's running,
- means it isn't (it might have crashed - it might never have started), and
? means the services doesn't have a status command, so there's no way the service command can work out what's what.


Program to compare two files line by line

meld
tkdiff
vim

meld is -my- favorite.

Console has a command for it:
diff {file1} {file2}


A fatal error has been detected by the Java Runtime Environment: SIGSEGV, libjvm

Solved: I was passing null values to my methods that's why I was getting this error message.


Can't boot without USB, grub-install and boot-repair both failed

sudo grub-install /dev/sda

  But I got the error:

Installing for i386-pc platform.
grub-install: error: failed to get canonical path of `aufs'.

Whether you know it or not, passing the /dev/sda device to grub-install implies installation of the BIOS-mode version of GRUB. (Of course, you may have passed that option in error.) Likewise, the response that GRUB is trying to install for the i386-pc platform also implies a BIOS-mode GRUB installation. I don't know offhand what the failed to get canonical path ofaufs'` message means. The BIOS-mode version of GRUB, though, is critical, because....

sudo fdisk -l

Device      ... Size       Type
/dev/sda1       512M       EFI System
/dev/sda2       208.1G     Linux filesystem
/dev/sda3       15G        Linux swap

The presence of an EFI System Partition (ESP) implies that the disk is set up for booting in EFI mode, not in BIOS mode. (As a side note, you've clearly cut lines of output from your fdisk command. You should not do this when you're asking for help. These lines might be helpful in diagnosing your problem, although they're probably redundant in this specific case.)

The vast majority of new computers today ship configured to boot in EFI mode by default. You can enable BIOS/CSM/legacy-mode support in the firmware, and some Ubuntu and Linux installation instructions recommend doing so; however, in most cases this is bad advice. See my page on the subject for information on why. It's unclear if you've made these changes yourself; the apparent presence of the BIOS-mode version of GRUB in your Ubuntu installation suggests you've installed in BIOS mode; however, the disk partitioning suggests you've installed in EFI mode.

Since this is a new installation, my recommendation is to configure your firmware to boot only in EFI mode and to then install an EFI-mode boot loader. There are many ways to do this. The three easiest are:

Use Boot Repair -- If you can get an Ubuntu emergency disk to boot in EFI mode, it should be able to re-install GRUB (in EFI mode) and you'll be good to go. The Boot Repair tool can do this semi-automatically; however, you must run it from an EFI-mode boot to be successful. If you switched to a BIOS-mode boot to work around problems booting the Ubuntu installation medium, you may need to re-create your Ubuntu installation medium or otherwise work around that boot problem first. See my page on the CSM, referenced earlier, for more on this subject.
Use rEFInd -- You can boot the computer using the CD-R or USB flash drive version of my rEFInd boot manager. (Download links for both are on that page.) Once you've booted, you can install the rEFInd Debian package or PPA. You should then be able to reboot and use rEFInd, rather than GRUB, to control the boot process.
Re-install Ubuntu -- If you reconfigure (if necessary) the firmware to boot in EFI mode and can get the installer to boot in that mode, re-installing Ubuntu is another option. This is overkill, but it may be easier than trying to fix your current installation, given that it's new.

EDIT:

From your Boot Repair output, there are some clues to the cause of the problem:

File system:       vfat
Boot sector type:  FAT32
Boot sector info:  No errors found in the Boot Parameter Block.
Operating System:
Boot files:        /EFI/Boot/bootx64.efi /EFI/ubuntu/MokManager.efi
                   /EFI/ubuntu/fwupx64.efi /EFI/ubuntu/grubx64.efi
                   /EFI/ubuntu/shimx64.efi
                   /EFI/Microsoft/Boot/bootmgfw.efi
                   /EFI/Microsoft/Boot/bootx64.efi

Note in particular the presence of Microsoft boot files (/EFI/Microsoft/Boot/bootmgfw.efi and /EFI/Microsoft/Boot/bootx64.efi). These files suggest that you did not delete the ESP, so the Windows boot loader files seem to be lurking alongside your Ubuntu installation. Also, check the efibootmgr output:

=================== efibootmgr -v
BootCurrent: 0000
Timeout: 0 seconds
No BootOrder is set; firmware will attempt recovery
Boot0000* USB Hard Drive 1 - Generic Mass Storage   BBS(HD,,0x900).......................................................................
Boot0001* Notebook Hard Drive   BBS(HD,,0x0).......................................................................
Boot0002* Notebook Ethernet BBS(128,,0x0).......................................................................
Boot0003* Windows Boot Manager  HD(1,GPT,2c19863f-1ed0-476e-a8e9-6d316ca2c4bb,0x800,0x32000)/File(EFIMicrosoftBootbootmgfw.efi)WINDOWS.........x...B.C.D.O.B.J.E.C.T.=.{.9.d.e.a.8.6.2.c.-.5.c.d.d.-.4.e.7.0.-.a.c.c.1.-.f.3.2.b.3.4.4.d.4.7.9.5.}...a................
Boot0004* ubuntu    HD(1,GPT,17667422-8dfe-45ba-9baa-5458a67b71db,0x800,0x100000)/File(EFIubuntushimx64.efi)

The Windows boot entry is still present there, too, which isn't surprising; however, the truly messed-up bit is the report that No BootOrder is set; firmware will attempt recovery. A working EFI relies on a variable called BootOrder to identify the order in which boot loaders will be run. This variable is absent on your computer. I've seen the same problem on a rather old HP 6470b laptop that I own, and no matter what I try, I've been unable to create this variable. In any event, the likely result is that the computer is trying to launch either the fallback boot loader (EFI/BOOT/bootx64.efi) or the Microsoft boot loader (EFI/Microsoft/Boot/bootmgfw.efi). If the boot loader launched is the original Microsoft boot loader, then it would flake out at this point because Windows is not installed. If you've copied something else to those files (knowingly or not), it might flake out if its support files aren't also present.

Since you say your computer is new, my first recommendation is to return the computer to the store for a refund and buy something else. The problem may be a sample defect (a bad NVRAM chip or the like), or it could be a bug in HP's firmware. If the former, a new version of the same computer might work; but if it's buggy firmware, a new computer will do nothing. (OTOH, if it's buggy firmware, there's a slim chance that a firmware update will fix the problem. Resetting the firmware options to their defaults might also help.) If you return the computer to the store for a refund, be sure to tell HP you did that, and why. Manufacturers will continue selling defective products unless they're made aware of the fact that they're doing so, and they take some pain (in the form of returns) for doing so.

If you refuse to get a non-broken computer, you must deal with it. The best way is to delete those Windows boot loader files from the ESP and to copy GRUB to the fallback filename of EFI/BOOT/bootx64.efi. (There's already a file in that location, but it's not clear if that's another copy of GRUB, another copy of the Windows boot loader, or something else.) You'll need to copy grub.cfg and perhaps other files from EFI/ubuntu to EFI/BOOT, too. If you use Boot Repair, there's an option on its Advanced page that will do this semi-automatically.

EDIT 2:

You can change the boot order using the -o option to efibootmgr, as in:

sudo efibootmgr -o 4,0,1,2

This example should keep the existing boot entries shown, but add the ubuntu entry to the front. In theory, this will make GRUB the default boot program, and everything should then start working. You can learn more about efibootmgr by typing man efibootmgr. (The same trick works for other commands; for instance, man ls will tell you about the ls command.)

That said, the fact that you had a non-existent BootOrder variable at the start makes me skeptical this will work; I suspect there's something flaky about your EFI that will cause it to fail. (Both the original Ubuntu installation and Boot Repair should have added the ubuntu entry to the start of the BootOrder variable, assuming they were run in EFI mode -- and the Boot Repair output you showed revealed no BIOS-mode boot loader on your disk, which implies they were run in EFI mode.)

There are two EFI System Partition(s), or partitions that fill that purpose, on your system, and I think you're getting them confused:

On the hard disk -- The ESP on your hard disk is /dev/sda1, according to your Boot Repair output. This partition should be mounted at /boot/efi when you boot the Ubuntu on your hard disk; but when you use the Ubuntu installation medium in "try before installing" mode, it either won't be automatically mounted or it will be mounted somewhere else, in a subdirectory of /media, IIRC.
On the installation medium -- It's not technically an ESP, but /dev/sdb1 on your installation medium serves the same role. It contains an EFI/BOOT directory with various boot files. Adjusting these files is pointless at best, at least in your case, because you want to get the system booting to the installed OS without using your installation medium.

If you're booted with the installation disk, modifying files on your hard disk's ESP requires mounting the ESP and then modifying those files. You'd do something like this:

sudo mkdir -p /mnt/foo
sudo mount /dev/sda1 /mnt/foo
cd /mnt/foo/EFI
sudo mv Boot Boot-old
sudo cp -r ubuntu BOOT
sudo mv BOOT/shimx64.efi BOOT/bootx64.efi

Note that typos (by me or by you) could make these commands fail to work as expected, and such a mistake could even make matters worse. If it works, this sequence of commands will copy Shim (which handles Secure Boot authentication) to the fallback filename of EFI/BOOT/bootx64.efi. Shim will then launch GRUB (grubx64.efi), which continues the boot process. If the efibootmgr -o command I presented earlier does not work, this sequence should get the system booting.

Beyond this, you're asking a lot of fairly basic questions, which is turning this question and its answers into a tangled web. I suggest you do some outside reading:

General overview of the Linux file system
Unix - File System Basics
Adam Williamson's blog entry on how EFI works
My page on installing Linux on EFI systems

Once you understand some of these basics, you may get more out of the answers here -- but be aware that we've traveled down a couple of blind alleys because of incomplete initial information and incorrect guesses. If you still have problems after reading at least some of the preceding, I recommend asking fresh questions, or taking the discussion to the Ubuntu forums, which are better set up for back-and-forth discussions. (This site is intended for answering relatively straightforward questions, not carrying on extended discussions.)


Why this process consumes a lot of memory? "collector"

kill -9 'pgrep -f collector' can be set to run with cron every so often, which will kill the collector PID.

As to what collector is, I was unable to find collector in the Ubuntu distro. There are several found with a search on COLLECTOR IN LINUX and they all 'phone home' with some kinda data set.


it seems your problem lies in the /etc/environment file? Can you show the contents of that file? The error seems to indicate you have a JAVA_HOME command instead of a setting.


xflock4 triggers standy instead of locking the screen

Open

  xfce4-keyboard-settings

(with terminal or press alt+f2 and paste the command)

You should get this windows:

Here you can determine the xflock4 shortcut.


Terminal stops writing its output to the file if the file is changed

You can't. When you open a file, the process gets a file handle. The file handle does not change even if the file is moved or removed. Thus, the process will be writing to the same file handle, which you moved to output_bak.txt. You will have to close a file and reopen it.

You can use unix utilities like tail to view the end of the file. tail -n 20 output.txt will output the last 20 lines of output.txt.

Tail can also provide a live view. tail -f output.txt will show content as it is written to the file, in a continuous stream, until you interrupt it with Ctrl+c.

This is by the way how logrotate works. Move the file, create a new empty file, and restart the process writing to the log file.


USB not booting linux on acer aspire 5750g

Looks like a video driver issue.  Select the nomodeset option (under F6) at the "Try/Install" screen.  Skipping some of the video install stuff is possible by typing a character at the screen with the two little icons at the bottom (a keyboard and a little stick person), then select language, ...  If that doesn't get you through, try one of the alterative installs which have even less video dependence.  Once you are running, you can install the appropriate proprietary video driver, and maybe add nomodeset to the /etc/default/grub file on the
GRUB_CMDLINE_LINUX_DEFAULT="quiet splash" line after the splash.


How can I uninstall a locale via command-line?

You can list locales with

localedef --list-archive

or with

locale -a

Corresponding file size is given by

ls -lh /usr/lib/locale/locale-archive

To remove unused locales you can do

sudo locale-gen --purge it_IT.UTF-8 en_US.UTF-8 && echo Success!

where it_IT.UTF-8 and en_US.UTF-8 are the only two locales I want. The && echo "Success!" at end is useful because locale-gen does not report errors if an unavailable or wrong locale is passed on command line.


Kernel Panic: VFS cannot open root device or unknown block error -6

It seems someone has been able to solve this issue here

Kernel Panic - not syncing: VFS: Unable to mount root fs on unknown-block(0,0)

They suggest running

sudo update-initramfs -u -k $(uname -r)

Then

sudo update-grub


Find the MAC address of your WiFi interface with ip link (It's the Link/ether value). and replace my MAC addr (00:0f:00:52:93:03) in:
echo -en "network:\n  version: 2\n  mac 00:0f:00:52:93:03\n  mtu 1492\n" | \
     sudo tee /etc/netplan/02-local-wifi-1492.yaml

I think this is the modern, netplan method.
Changing the MTU on the lo and enps0 has no effect on packets routed out through wlp2s0, and is a Bad Idea.


You have an error in your Geany Execute command. To run your program from Geany with an optional argument c, you should go to the Build menu, and under Set Build Commands, change

Execute: "./%e c"

to

Execute: "./%e" c


Can I Install ubuntu 14.04LTS alongside Windows Vista?

You can choose 12.04 or 14.04 but not 13 because all versions of 13 (13.04 and 13.10) have reached EOL just like WindowsXP so they are no longer supported. 12.04 and 14.04 are LTS or long term support versions and will be supported for a few years.

Picture from http://en.wikipedia.org/wiki/List_of_Ubuntu_releases


The best way to refresh the list is to go to the command line and type:

sudo iwlist wlan0 scan

Assuming your wifi is called wlan0 (it might be wlan0 or something else) see ifconfig for details.

On newer versions of Ubuntu you can leave out the wifi name and it will scan all wireless cards:

sudo iwlist scan

This command will refresh the list by asking the wifi to rescan. You can only do this as root and if you do it as non-root it will simply print the list of known networks without refreshing.


I just thought to make the situation simple & attempt to figure out if Linux depends on Haskell.

"Linux", properly considered, is just the operating system kernel. I can guarantee that isn't one ioata of Haskell in the Linux source code, nor in the GCC toolchain plus the few other utilities that are needed to build Linux. So there isn't even a build dependency on Haskell, let alone a runtime dependency.

Haskell is 100% optional.


The kernel documentation doesn't say a word about SI prefixes. Where prefixes do appear in documentation, they appear without the silly i (k, M, etc., instead of ki, Mi) (see man 5 proc, for example). Since GNU tools didn't gain SI prefix support until well after Linux was released, and Linus doesn't look like someone who changes kernel code simply because a standards organization prefers different prefixes, I speculate that Linux, when it does use these prefixes, uses binary prefixes.

The manpages developed as part of the kernel documentation, however, does discuss this. See man 7 units:

Thus, today, MB = 1000000B and MiB = 1048576B.

In the free software world programs are slowly being changed to con‐
form.  When the Linux kernel boots and says

      hda: 120064896 sectors (61473 MB) w/2048KiB Cache

the MB are megabytes and the KiB are kibibytes.

Wikipedia references this, and mailing list posts by ESR (aka Eric S. Raymond, a well-known kernel developer)  ([1], [2], [3], [4]) show that a patch changing kB to KiB, etc. in one part of the documentation, was accepted, but part of it continued to use the older variants. Thus, prefixes are binary (or are intended to be binary).


Okay, I managed to reinstall ubuntu successfully and I figured out how to avoid causing the same problem a second time around so I figured I’d post here. It has to do with RAID/AHCI and cryptswap.

Apparently the reason the disk disappeared was that something modified one of the disk settings in the BIOS, and I had to go back and change it from RAID to AHCI. That lets you do a fresh reinstall of ubuntu on your hard drive again.

The reason doing a routine software update causes this problem is because for some reason a cryptswap1 thing was demanding a password to allow the updater to do stuff, and unless you have “Details” enabled in the software updates, the updater would skip some important stuff and you’d end up with a broken system. To do the update right you have to watch the “Details” tab and supply a password (can be any string you just have to type something) each time cryptswap1 asks for a password. Then use one of the other answers on this website to get rid of cryptswap1 for good.

Hope this helped


i have same problem.
dell inspiron 7520
ubuntu 15.10

00:02.0 VGA compatible controller: Intel Corporation 3rd Gen Core processor Graphics Controller (rev 09)
01:00.0 VGA compatible controller: Advanced Micro Devices, Inc. [AMD/ATI] Chelsea LP [Radeon HD 7730M] (rev ff)

sudo aticonfig --initial -f

No supported adapters detected

try this

  If you are using multiple AMD graphics cards or AMD dual graphics (i.e.: notebook users), use:

  sudo amdconfig --adapter=all --initial

Result:

Using /etc/X11/xorg.conf
Saving back-up to /etc/X11/xorg.conf.fglrx-0

  The Catalyst Control Center should now offer a choice between the integrated Intel graphics and the dedicated AMD graphics. To switch,
  select the graphics you want to run. Because the change is not
  dynamic, a reboot is required.

...and use this script

cd ~
wget -c --referer='http://support.amd.com/ru-ru/download/desktop?os=Linux+x86_64' https://www2.ati.com/drivers/linux/radeon-crimson-15.12-15.302-151217a-297685e.zip
unzip radeon-crimson-15.12-15.302-151217a-297685e.zip
cd fglrx-15.302
sudo sh amd-driver-installer-15.302-x86.x86_64.run --buildandinstallpkg
sudo apt-get -fy install
sudo amdconfig --initial -f
cd ~
sudo rm -r fglrx-15.302


Thought I'd update this in case anyone else needs it. This is my final, working rule set for ufw that allow PIA VPN to connect automatically without disabling the firewall; allows communications between local networked computers; yet still denies all traffic outside the local network that does not go through the VPN tunnel:

To                         Action      From
--                         ------      ----
Anywhere on tun0           ALLOW       Anywhere
1194/udp                   ALLOW       Anywhere
192.168.1.0/24             ALLOW       192.168.1.0/24
5353                       ALLOW       Anywhere
Anywhere (v6) on tun0      ALLOW       Anywhere (v6)
1194/udp (v6)              ALLOW       Anywhere (v6)
5353 (v6)                  ALLOW       Anywhere (v6)
Anywhere                   ALLOW OUT   Anywhere on tun0
1194/udp                   ALLOW OUT   Anywhere
192.168.1.0/24             ALLOW OUT   192.168.1.0/24
5353                       ALLOW OUT   Anywhere
Anywhere (v6)              ALLOW OUT   Anywhere (v6) on tun0
1194/udp (v6)              ALLOW OUT   Anywhere (v6)
5353 (v6)                  ALLOW OUT   Anywhere (v6)


Error while install vte-eg 'No package 'libpcre2-8' found'?

Installing libpcre2-dev fixed my problem


Easiest approach would be using same user and group id and username in all of the computers (and server)


Is there a way to make bigger the characters of xterm?

You can access the properties of xterm and change their configurations:
By holding down the Control key upon your keyboard and clicking upon the body of the window with either your left, right, or center mouse button.
So to change the the font size:
Press the Control key with one hand, and click the right mouse button.
A menu appears, with the following font alternatives:
Default (fontdefault)
     Set the font  to  the  default,  i.e.,  that given by the *VT100.font resource.
Unreadable (font1)
     Set   the   font   to   that  given  by  the *VT100.font1 resource.
Tiny (font2)
     Set  the  font  to   that   given   by   the *VT100.font2 resource.
Small (font3)
     Set   the   font   to   that  given  by  the *VT100.font3 resource.
 Medium (font4)
     Set  the  font  to   that   given   by   the *VT100.font4 resource.
Large (font5)
     Set   the   font   to   that  given  by  the *VT100.font5 resource.
Huge (font6)
     Set  the  font  to   that   given   by   the *VT100.font6 resource.


locale: Cannot set LC_CTYPE to default locale: No such file or directory locale

Insert into /etc/default/locale:

LC_CTYPE="en_US.UTF-8"
LC_ALL="en_US.UTF-8"
LANG="en_US.UTF-8"

And regarding the missing locales, to generate them: sudo dpkg-reconfigure locales


How to install tar ball sublime text on Ubuntu?

The tarball is not meant to install sublime text on the system.

Instead use a package from the apt repository:

wget -qO - https://download.sublimetext.com/sublimehq-pub.gpg | sudo apt-key add -
sudo apt-get install apt-transport-https

# stable version
echo "deb https://download.sublimetext.com/ apt/stable/" | sudo tee /etc/apt/sources.list.d/sublime-text.list

sudo apt-get update
sudo apt-get install sublime-text

Source: https://www.sublimetext.com/docs/3/linux_repositories.html


It'easy to setup your windows as a first Entry for OS load. type the following command in terminal.

sudo gedit /boot/grub/grub.cfg

then copy the menuentry for windows as shown in the sample code. The sample code is at below.Dont copy/cut this(sample) code. This is just sample to show that the menuentry code for windows in your grub.cfg file will look like this.

*menuentry 'Windows 7 (loader) (on /dev/sda1)' --class windows --class os $menuentry_id_option 'osprober-chain-28CAFAF2CAFABAE0' {
    insmod part_msdos
    insmod ntfs
    set root='hd0,msdos1'
    if [ x$feature_platform_search_hint = xy ]; then
      search --no-floppy --fs-uuid --set=root --hint-bios=hd0,msdos1 --hint-efi=hd0,msdos1 --hint-baremetal=ahci0,msdos1  28CAFAF2CAFABAE0
    else
      search --no-floppy --fs-uuid --set=root 28CAFAF2CAFABAE0
    fi
    chainloader +1
}*

Copy/cut similar to above code from your grub.cfg file and paste just below this line in grub.cfg file

if [ "${linux_gfx_mode}" != "text" ]; then load_video; fi

This will make windows as a first entry at boot time.


Get keyboard input without requiring root and without x11

The best solution I could find is to make a separate daemon that run as service which monitor /dev/input/.. events and let the other user tools to connect to itself and listen for input events.

Think something that replace XEvent. (bringing those input events to user space)


There are 2 version: BSD and GNU. The GNU version support -l with -p (or at least does state you can used them together). The man page states we use an edited BSD version.

This is from the GNU version:

NAME

netcat - GNU Netcat Manual

CONTENTS

SYNOPSIS

    netcat [options] hostname port [port] ...

    netcat -l -p port [options] [hostname] [port] ...

    netcat -L hostname:port -p port [options] ...

===

This is from the BSD man page:

Name

nc - arbitrary TCP and UDP connections and listens
Synopsis

nc [-46DdhklnrStUuvzC]
     [-i interval [-p source_port]
     [-s source_ip_address] [-T ToS] [-w timeout]
     [-X proxy_protocol] [-x proxy_address[:port]] [hostname[port[s]]

...

-l' Used to specify that nc should listen for an incoming
connection rather than initiate a connection to a remote host.
It is an error to use this option in conjunction with the -p, -s, or -z options.
Additionally, any timeouts specified with the -w
option are ignored.

Weird indeed. But it looks like we use either the GNU where the manual page points to the original BSD manual or we use an altered BSD version and also with the wrong manual page.


Gnome 3 Shell suspend has me locked out of my computer

After failing to find a key or key combination to resume, and after failing to boot a cd and a USB key, it was clear I was going to have to clear my computer's ram. I took the lid off the computer and looked for a cmos battery. In one corner I found a coin battery mounted vertically in a plastic case secured by  two tiny arms that hooked just over the top of the battery. I was unable to bend these arms back enough and pull the battery out with my other hand because there wasn't enough space. Frustrated, I stuck one end of a strip of scotch tape to the battery and pulled on the other end while bending the little arms back. The tape came off, but the battery had come up enough that it was holding the arms back some. After trying this again I had the battery dangling on the end of the tape. I waited about a minute and put the battery back in the mount, closed up the computer, and turned it on. It booted normally -- problem solved.


No unused kernels in /boot but still 100% full

There was a .Trash folder in /boot containing all the deleted files. Shift + Del and I've got 450MB freed.
Thanks all for your answers.


Ubuntu 18.04, complex network configuration with Netplan

From OP's edits:

  I fixed this by wrapping my interfaces in brackets "[" "]"


modify another user's password entry with sudo power

Just type sudo passwd username to change username's password.


Webinar woes, won't play in Firefox or Chrome

This site attempts to load insecure scripts. The loading of the Scripts will be blocked by the browser.
In this specific case it is probably because that some scripts be loaded via a connection without SSL.
Open the URL and click the marked icon:

Chrome/Chromium

Firefox


Workaround

OS: Ubuntu 18.04

removing the clock is not possible unless digging the core files of gnome-shell files which is very difficult.

instead you can hide it by editing ubuntu.css file.

Disclaimer: playing with gdm3 files is very dangerous, small mistakes will stop access to gnome desktop session. Only tty will work. i have several times reinstalled Ubuntu in such cases. although i have successfully hidden the clock-display on lock-screen. proceed with your own risk.

open the file /usr/share/gnome-shell/theme/ubuntu.css with below command.

sudo -H gedit /usr/share/gnome-shell/theme/ubuntu.css

search for "screen-shield" and find the below content

.screen-shield-clock-time {
  font-size: 72pt;
  text-shadow: 0px 2px 2px rgba(0, 0, 0, 0.4);
  font-feature-settings: "tnum"; }

.screen-shield-clock-date {
  font-size: 28pt;
  font-weight: normal; }

then make the font-sizes to 0 like below

.screen-shield-clock-time {
  font-size: 0pt;
  text-shadow: 0px 2px 2px rgba(0, 0, 0, 0.4);
  font-feature-settings: "tnum"; }

.screen-shield-clock-date {
  font-size: 0pt;
  font-weight: normal; }

save the file, Refresh Gnome-Shell Alt+F2 r Enter.


It is a good idea to use

sudo apt-get autoremove

from time to time. Apt-get manpage says:

autoremove
     autoremove is used to remove packages that were automatically
     installed to satisfy dependencies for other packages and are now no
     longer needed.

This removes "remainings" of previous kernel versions and I'd bet it should free enough disk space in your case, too.


Seems like a disk problem: so hardware.
Depending on how bad the problem is with the disk, there may still be hope to recover most if not all of the data.
The thing says that the problem is on the /dev/sda1 partition, which is the root filesystem.
With Ubuntu, it's a traditional choice to install the root filesystem in one partition, while installing user data, the so-called home filesystem on another, dedicated partition.
If this user-data-oriented home section is indeed located on its separate, dedicated partition, then there is a very high chance of full recovery of data.
If however the home section was installed together with the (now-problematic) root filesystem (on the same partition), the outlook may be quite different.
One thing to keep in mind: it's best to exhaust all options at copying the data out before running the fsck repair utility on a partition containing user data, because there is some chance that fsck ends up not being able to repair the partition, and then it would leave you in a worst state than before.
So it's a kind of all-or-nothing with fsck.
Update on this last sentece: according to high number of upvotes on this answer (suggested by @steeldriver), there seems to be a decent chance that fsck can deal with the problem.
Nevertheless, even in the case of success, there should be a lesson learned, and from then on important data should be regularly backed up to an independent device.

For the data recovery attempt, I would use a Live USB device, the one, or a similar one, that was used to install the OS in the first place.
These Live USB installer devices have a function: "Try Ubunutu without installing". If you use this feature, it gives you an Ubuntu operating system running on the computer that's operating entirely from the USB device, bypassing the faulty hard drive.
While using this USB-provided OS instance, it is possible to "mount" (connect) the internal HDD's partition that contains the user data (if it's indeed a dedicated partition separate from the problematic root filesystem). From then on it would be only a matter of attaching another storage medium to which the files can be copied.


How to set GROOVY_HOME environment variable on Ubuntu

Create the file /etc/profile.d/groovy.sh by opening a terminal window and running this command:

sudo -H gedit /etc/profile.d/groovy.sh

Give the file this contents:

export GROOVY_HOME=/usr/share/groovy
PATH="$PATH:$GROOVY_HOME/bin"

Then save, log out and log in again.


Hibernating my Ubuntu 10.10 takes a bit too long

Install the uswsusp package.  It compresses the data as it writes it out so the process goes faster.  5 minutes seems a bit extreme though, pointing to a more serious hardware problem.


How to fix apt-get upgrade (apt-get install -f) error?

Try using autoremove

sudo apt-get autoremove

This is the command that cleans up dependencies after a package has been removed.


How to turn off the display via the command line?

I think you are looking for

xset dpms force off

However, you need to make sure that your acpi is enabled. You can check this with

cat /proc/acpi/info

Another option could be

setterm -powersave powerdown


5.7 won't be released on 18.04. For more recent kernels on an LTS, it is best to opt-into the LTS Enablement Stacks as described in the  Ubuntu wiki
For desktop use:
sudo apt-get install --install-recommends linux-generic-hwe-18.04 xserver-xorg-hwe-18.04

For server use:
sudo apt-get install --install-recommends linux-generic-hwe-18.04


RabbitVCS not displaying Compare Revisions correctly with Meld in Ubuntu 16.10

That's because a bug was introduced in rabbitvcs-core version 0.16-1.1, which is the version in the ubuntu repo for 16.10/yakkety. the bug causes the "compare to previous revision" action to always export the head revision instead of the desired revisions.

Someone wrote a fix that hasn't been accepted yet: here.

One easy solution is just to downgrade rabbitvcs-core to 0.16-1 which works fine and is available in the ubuntu repo for 16.04/xenial. don't forget to mark the package as held afterwards so software updater doesn't upgrade over it.

sudo apt-add-repository "deb http://us.archive.ubuntu.com/ubuntu xenial universe"
sudo apt install rabbitvcs-core=0.16-1
sudo apt-mark hold rabbitvcs-core


How do I resolve this issue regarding installing Intel Graphics Driver?

To be able to download the graphic driver from Intel, you have to add their GPG keys to your system.  Ubuntu will otherwise be unable to validate that the files are correct.

To add the keys, open a terminal window and enter something like this:

wget --no-check-certificate https://download.01.org/gfx/RPM-GPG-KEY-ilg \
      -O - | sudo apt-key add -

or

wget --no-check-certificate https://download.01.org/gfx/RPM-GPG-KEY-ilg-2 \
     -O - | sudo apt-key add -

Note Intel seem to update their GPG keys regularly, and their instructions do not get updated as often leading to forum posts complaining. However, if you don't mind guesses, you'll note that the difference between the two keys above is -2 appended to the URL. For 16.04's packages at least as of 14 Oct 2016, Intel are on -4. My bet is that the next one's likely to be -5!


OpenJDK not working in Ubuntu 12.10 on Firefox

Have you checked that your Java plugin is enabled in Firefox? Go to Tools / Add-ons / Plugins, and validate that it is enabled.


install ubuntu (11.10 or above) on dell xps 17 - dual booting

I have a Dell with a i5 2320 (Sandy Bridge) and have had no problems with 12.04.  Before that I had both 11.04 and 11.10 installed on my old Dell 2.8Ghz Dual core built in about 2004 and had no problems with either of those so I'm not sure what problems you saw.

In 12.04 I would suggest:

Installing mesa-utils will improve the display(mine was slightly too large for the screen without it)

Installing libtxc-dxtn-s2tc0 will provide the texture compression library needed for mesa to display some of the better games(Note: some games that need the s3tc compression will not load as they think that the card does not support it(Psyconauts is one) and must be forced in the terminal with force_s3tc_enable=true (program) (even with that my GPU will not run Psyconauts but will force enable others)

Those are the only things I can think of so you should be fine installing 12.04 on your computer.

Note: if you have a non-integrated GPU(AMD,Nvidia, ATI) you will need to install the proprietary drivers for those and there are plenty of answers here on askubuntu.  I will defer to those as I don't have any and have never had to install them.  From what I have seen in passing, hybrid graphic cards require some work to get working if they work at all, but again I cannot verify any of those problems myself.


Can´t set up Wifi, says it´s using alternate drivers(?)

So, at the end I just disabled Secure Boot and that was it. Maybe I´ts basic as hell, but it was my first Linux installation. So, if any future rookies see this, just get to your bios boot options and disable secure boot.


Bluez stuck at high CPU and bluetooth not working

Did you get it to work again? Mine still doesn't work and I keep on turning off the bluetooth service after I booted my laptop...

(my topic)


Ubuntu 18.04 sound doesn't work, dummy output

I figured it out. Before I reinstalled Ubuntu I installed a newer kernel, running the command
sudo modprobe -v snd-hda-intel showed it was looking for a kernel related file in /lib/modules/ that didn't exist. But there were files for the kernel Ubuntu came with, booting into the older kernel fixed the issue I was having.


/sys/class/sound/hwC0D2/init_pin_configs:
0x14 0x00000000
0x15 0x00000000
0x16 0x00000000
0x17 0x00000000
0x18 0x00000000
0x19 0x00000000
0x1a 0x00000000
0x1b 0x00000000
0x1c 0x00000000
0x1d 0x00000000
0x1e 0x00000000
0x1f 0x00000000

The BIOS of your notebook is utter crap and does not provide any pin configuration, so the driver has to assume that the sound chip is not connected to anything.

Try to set the model option of the driver.

If you had 13.04, you could use hdajackretask from the alsa-tools-gui package to configure the pins by hand.


Please kindly and strictly follow these steps:

Boot computer into recovery mode
At the recovery mode type the following to mount your filesystem in read/write mode:

mount -o rw,remount /

WARNING DON'T IGNORE SPACES, COPY AND PASTE IF YOU MUST

Then get to the /etc/fstab for editing with:

nano /etc/fstab
Comment out any line with the mount instructions for directory /media by adding the # character at the beginning of that line
After the edit use the following commands to save and close the nano editor

Ctrl + o + ENTER
Ctrl + x

Now reboot the system.


Dependecies error when trying to insatll wine

1) Open synaptic package manager and repair broken paquets
2) Open terminal and type:

sudo add-apt-repository ppa:ubuntu-wine/ppa
sudo apt-get update
sudo apt-get install -y wine1.7

You can install wine 1.8

sudo apt-get -y install wine1.8

Or wine 1.9

sudo apt-get -y install wine1.9


Changing default values in /etc/ssh/sshd_config using cloud init config

Apparently adding this one into /etc/ssh/sshd_config does the trick (tested, works):
runcmd:
  - sed -i 's/ClientAliveInterval 300/ClientAliveInterval 30000/' /etc/ssh/sshd_config
  - sed -i 's/ClientAliveCountMax 0/ClientAliveCountMax 50/' /etc/ssh/sshd_config
  - service ssh restart


How do I resize partitions using the simple installation wizard (installing a second Ubuntu)?

When logged in on 11.10, open a terminal (Ctrl+Alt+T) and type the following:

cat /etc/mtab

There you will find which partitions are currently mounted. The first is the location of the partition (for instance: /dev/sda2), the second parameter gives you where it is mounted.
Look for / or /home/.

Write down the partitions (/dev/...).

Reboot from the DVD. The partitions you wrote down were used for 11.10, so you don't want to touch that. The /dev/... you didnt saw before is the new partition made for 12.04.


Does sudo apt list --upgradeable show kernel updates?

Yes it does. After you run sudo apt-get update, if there's a kernel update, then apt list --upgradeable should show some packages like linux-headers-4.4.0-something and linux-image-4.4.0-something.


Netplan configuration problem for local NAS-Ubuntu server 20.04

My netplan config looks like this:
# This is the network config written by 'subiquity'
network:
    version: 2
    renderer: networkd
    ethernets:
    etc.

It seems the first line "network:" has been deleted from your file. I'm pretty certain it will work after that line is added.
After that, your file should look like this (with the same indentation):
# This is the network config written by 'subiquity'
network:
    version: 2
    renderer: networkd
    ethernets:
        enp4s0:
            addresses: [192.168.1.100/24]
            gateway4: 192.168.1.1
            nameservers:
                addresses: [4.2.2.2, 8.8.8.8]

Also note that it should be nameservers, not nameserver (per examples), and you need spaces after each colon.


How do I make files copied over the network from my Windows computer be owned by me?

You should be able to do it with the --no-preserve flag in cp

cp --no-preserve=ownership source destination

edit: That will still have weird permissions (owner will be the user calling cp though). This will probably work better when copying from ntfs:

cp --no-preserve=ownership,mode source destination

That will match it to the bitmask of the folder being copied into, so if you are logged in as "user-a" and copy into a dir with drwxr-xr-x perms (0755) the files will be owned by "user-a" and have -rw-r--r-- perms (0644).


I found the file responsible for setting up the mobile session in lightdm at the login screen:

sudo apt-get install kubuntu-mobile-default-settings

This will get you all the kubuntu artwork aswell for the mobile desktop.


No, it won't work that way.  You will need multiple bridges, one for each vlan.

See:
https://serverfault.com/questions/414115/linux-vlans-over-bridge


How can I use the default theme from 12.10 in 12.04?

Go to /usr/share/themes and copy any theme you want to your home directory under .themes. I'm not sure if a theme from upper version will work properly ;)


how to boot a live-system with proprietary ATI drivers / fglrx?

You can make it persistent. Utilities like Startup Disk Creator and Unetbootin allow you to make a persistent USB drive. In such systems, changes you make, such as installing packages, drivers, etc., are preserved across reboots.

In Startup Disk Creator:

Select some reasonable storage space, like 2GB. Then use it boot in a system with a network connection and install the drivers.

Another option is to customize the live image: How to customize the Ubuntu Live CD?


I can't compile a simple sample, `No rule to make target '/usr/lib/x86_64-linux-gnu/libGL.so`

Solved:

booted in safe mode
chose repair packages in order to make it mount filesystem in read/write automatically
dropped root console
su elect to login as me
cd Downloads and sudo bash .NVIDIA-driver
reboot
it works as a charm


need to revert to windows operating system ,but got stuck in ubuntu

Well, that can be done, sort of. No easy way :

Can you enter BIOS ?

1.1 If you can :
Do you have recovery or Windows installation media ?

If you have :

Change your boot order to boot from that media
Recover/repair your Windows boot partition find a way, somewhere)

If you dont :
Go get it (somewhere)

1.2 If you can't :

Plug off your hardisk, enter BIOS, change boot order, then go with (1.1)

Can you enter Windows after your boot partition recovered/repaired ?

2.1 If you can :

Find your Windows boot partition location.
Recover/repair your linux bootloader (GRUP) / reinstall ubuntu (if your /home in the same partition with /root, they will completely destroyed).
Make sure GRUP overwrite Windows boot at same partition.
Make sure there no other GRUP installed in other partition. if there is another, find a way to delete it.

2.2 If you cant :

Looks like some of your Windows system file missing. You need to repair or      reinstall Windows.

Your system will boot into GRUP >> Find Root location >> Load Ubuntu

If you choose Windows >> GRUP find Windows boot location >> Load Windows

There is another option, over that long way. Straight forward, repair your boot partition from GRUP command promt. But if you are linux newbie like me :) I dont recommend that. Trust me, I have tried it, hours of drama, wasting my time. Your Windows still there, not going anywhere, you just need find a way, so your system boot into there.


avahi & nsswitch.conf with `mdns4` and subdomain resolution from peers

Technically, the requested/previous behavior is against mDNS spec; so understand the compatibility issues that presents. You'll need to either use explicit mappings or third-party tools with Avahi to get the desired out come now.
You could also use an older version of nss-mdns that should do the trick(it appears to resolve to the host before forwarding to Avahi, subsequent versions seemed to have removed such support). But this would only work for each system configured this way, see below for detailed explanation.
Against spec
RFC 6762, Section 3 - Multicast DNS Names:

This document allows any computer user to elect to give their computers link-local Multicast DNS host names of the form: "single-dns-label.local.".
...
This document recommends a single flat namespace for dot-local host names, (i.e., the names of DNS "A" and "AAAA" records, which map names to IPv4 and IPv6 addresses), but other DNS record types (such as those used by DNS-Based Service Discovery [RFC6763]) may contain as many labels as appropriate for the desired usage.

That seems to imply that subdomains are not officially supported for mDNS. Which also seems to be re-inforced with other implementations / platforms:
Windows does not support this:

My only disappointment is that the windows implementation of Bonjour/Avahi does not support the aliases that this implementation announces, it will only see the main avahi hostname normally announced (ie server.local in our example above).

macOS does not support this:

It returns an error if the name has more than two labels, as in the case of foo.bar.local.

The README for nss-mdns does reference some rules that the minimal variants use to decide if they should be sent to Avahi to handle. I came across this comment on the nss-mdns github repo that provides some dates for context:

The two-label limit heuristic was implemented in Mac OS X v10.5, released 2007-10-26
The unicast SOA heuristic was implemented in Mac OS X v10.6, released 2009-08-28

These rules were introduced in the 0.11 release of nss-mdns at the start of 2018, a little over a decade since the previous 0.10 release, relevant changelog note:

nss-mdns now implements standard heuristics for detecting .local unicast resolution and will automatically disable resolution when a local server responds to .local requests

Your referenced AskUbuntu question says the change was introduced possibly from Ubuntu 18.10 release, which is understandable as 18.04 would have been an LTS release making the update less likely to be approved.
This reveals that nss-mdns was previously not following such due to the lack of maintenance/updates for so long, both of those changes by Apple were added after the 0.10 release of nss-mdns. As the relevant github issue clarifies with reverse lookup logic and the drawbacks/risks it was causing.
There was a long standing bug report for mdns being handed queries to resolve which blocked until timeout before falling back to standard DNS, which understandably caused quite a few problems for users, notably those interacting with non-mdns .local FQDNs from Microsoft Active Directory.
To get that old behaviour, I think you may need to revert back to 0.10 of nss-mdns.
One further gotcha is that in 2020, while Windows 10 is said to be improving it's mDNS support, Android is still lacking it (beyond developers explicitly configuring for such within their apps). There is workarounds such as Unbound or CoreDNS which both have plugins to forward a Unicast DNS query to a Multicast one, however Avahi needs to be configured so that the hosts advertise the published address so that they're discoverable.
Avahi and NSS
Name Service Switch (NSS) is for your local system to handle lookup queries, here it can be deferred to your /etc/hosts, local DNS, systemd-resolved, mDNS and so forth. Most of your software will utilize it, but that is not always the case, especially with some utilities like host, dig, drill, nslookup which all bypass that and query DNS directly.
Avahi does not defer to NSS, but rather NSS defers to Avahi via nss-mdns. Thus it has nothing to do with how external requests via other devices on the network are handled. You can test queries for Avahi without NSS being involved by using avahi-resolve --name myhostname.local --verbose.
I believe other implementations of mDNS can be more strict/limited configuration wise, so keep in mind that regardless any Windows and macOS clients would likely not work, similar to how they may only handle the .local TLD for mDNS.
Configuring Avahi to respond to more than a hostname
You can configure nss-mdns to allow resolving additional labels via /etc/mdns.allow (when not using the minimal variant in your /etc/nsswitch.conf hosts: line). Without this, anything using NSS would likely send a Unicast DNS query instead, skipping mDNS.
After configuration, you may need to restart any process for it to reload that configuration, or you can test with a CLI command like ping. While that does allow for the expected resolving behavior, you'll notice a common timeout response of 5 seconds. Avahi itself is failing to find a hit for the query response, because nothing is setup to respond for that hostname.
Additionally, the file /etc/avahi/avahi-daemon.conf does not support . within the values for host-name or domain-name, these are for single labels. However, you can publish an explicit mapping manually with avahi-publish:
avahi-publish -a -R test.hostname.local 192.168.1.42

And the daemon will respond to this, but does not report it as discoverable via avahi-browse -a. The -R option is important, in that it will allow you to publish for the same IP address (otherwise complains about a local name collision). Alternatively, you can also define these in /etc/avahi/hosts with each line being the IP address followed by a hostname(which can likewise have a .), there should be some comments and examples in an existing file at that location. The file based approach does not have an equivalent to the -R option of  avahi-publish, thus specifying an IP address that's already been mapped to a hostname will be ignored. avahi-daemon does not require a restart when modifying this hosts file.
Note that for queries without avahi-resolve to work you would need NSS configured to use a non-minimal mdns variant such as mdns4, scoping to IPv4 (as opposed to mdns which also covers IPv6) can also lead to faster results (as opposed to waiting for the 5 second timeout, and then receiving an IPv4 response, avahi-resolve will respond promptly regardless however). You can also test queries without modifying /etc/nsswitch.conf with getent --service=mdns4 hosts test.hostname.local, change --service value to mdns4_minimal, mdns, etc.
Avahi via D-Bus
Providing explicit IP addresses kind of defeats the purpose a bit, but if the device runs Avahi, you should be able to have it list a series of labels/subdomains to the hostname via a script/program that communicates with Avahi over it's D-Bus API, like this old python one, they moved their answer snippets to a Github repo, which has quite a few forks including one porting to python3 if the old code hasn't aged well. For Docker users, similar can be found on DockerHub when searching for avahi images, I believe there was one that integrated with Traefik and docker labels to expose the containers over mDNS via Avahi.
Avahi for DNS-SD
You can still leverage mDNS for how it's typically used with DNS-SD(Service Disovery) in devices such as printers. You can provide a friendly string as a service name, and indicate the service type. Another device can then use DNS-SD to query for devices of interest and interact with them.
Another alternative that may work is Dynamic DNS (DDNS), which would allow a device to update DNS record for it's IP address. There are also more involved service discovery software like Hashicorp Consul.


You can make an installable disk the same way you made one for ubuntu, either make it a usb stick or a cd...      http://xubuntu.org/getxubuntu/requirements/     has minimum requirements as well as lubuntu, when you run throught the set up the installer is the same as the one for ubuntu so it will be framiliar to you - dureing the setup it will recognize that there is a version of ubuntu already installed and will give you the option of over writing that installation only -  i recently did this going from ubuntu 14.04 to ubuntu studio 14.04..   i am running hp laptop dual booted with win 8.1


Ubuntu loads wrong icons theme and fonts

I have faced the same problem when replaced my HDD (hard disk drive) with SSD (solid state drive). Fonts started looking just like in your pictures! I solved this by disabling the Ubuntu user auto-login in a system. When I switch my laptop, I have to enter password to see desktop but fonts and themes are now looking correct.


Thanks for OldFred for helping me solve this.  The solution was to replace "quiet splash" with "nomodeset" in the grub.


Dell Vostro 2520 has flickering green line to top of screen after running system update

You can install Ubuntu version 11.10 and after install only the updates and drivers that you need.


I was able to restore a broken avi index using this

$ mencoder -forceidx input.avi -o output.avi -oac copy -ovc copy

Source: http://compbrain.net/archives/18

However, the file was playable in VLC before. After repairing the index, VLC's warning just disappeared.


How do get the Ubuntu install disk to show all drives

You've got a single SSD set up in RAID mode, and the Ubuntu installer won't recognize your SSD until you switch your disk setting in the BIOS from RAID to AHCI.

Making that switch comes with some problems though, as Windows will no longer boot.

You don't need to reinstall Windows...

Below, you'll find two different ways to solve this problem.

Make sure to have a backup of your important Windows files!

Choice #1: Looking at this article https://samnicholls.net/2016/01/14/how-to-switch-sata-raid-to-ahci-windows-10-xps-13/ will show you how to make the change without having to reinstall Windows.

Boot to Windows with your current SATA controller configuration
Open Device Manager
Expand Storage Controllers and identify the Intel SATA RAID Controller
View properties of the identified controller
On the Driver tab, click the Update driver… button
Browse my computer…, Let me pick…
Uncheck Show compatible hardware
Select Microsoft as manufacturer
Select Microsoft Storage Spaces Controller as model #
Accept that Windows cannot confirm that this driver is compatible
Save changes, reboot to BIOS and change RAID SATA Controller to AHCI
Save changes and reboot normally, hopefully to Windows

Now you should be able to install Ubuntu in a dual-boot configuration.

Choice #2: See http://triplescomputers.com/blog/uncategorized/solution-switch-windows-10-from-raidide-to-ahci-operation/

Right-click the Windows Start Menu. Choose Command Prompt (Admin).
If you don’t see Command Prompt listed, it’s because you have already been updated to a later version of Windows.  If so, use this method instead to get to the Command Prompt:

Click the Start Button and type cmd
Right-click the result and select Run as administrator

Type this command and press ENTER: bcdedit /set {current} safeboot minimal

If this command does not work for you, try bcdedit /set safeboot minimal

Restart the computer and enter BIOS Setup (the key to press varies between systems).
Change the SATA Operation mode to AHCI from either IDE or RAID (again, the language varies).
Save changes and exit Setup and Windows will automatically boot to Safe Mode.
Right-click the Windows Start Menu once more. Choose Command Prompt (Admin)
Type this command and press ENTER: bcdedit /deletevalue {current} safeboot

If you had to try the alternate command above, you will likely need to do so here also: bcdedit /deletevalue safeboot

Reboot once more and Windows will automatically start with AHCI drivers enabled.


When are new kernels in an Ubuntu release?

Since ubuntu does not follow the rolling release model. No new software except a security update is introduced in the repositories and therefore a new kernel will not be available.

If you still want to use a new kernel release you can try mainline builds.


You would need to fork gnome-control-center, hard-code the 4GB value into it, and recompile. Or you could make a screenshot of your current System Details, photoshop 4GB over it, and write a small script that displays your new image over the regular window. I do NOT recommend either of these methods. You could be as creative as you like, but running out and buying an extra 2GB would be faster and safer in most cases.


Finer control over units in nautilus size column

What you want is impossible without modifying Nautilus sources (see update below)

However, there's an awesome tool included with Ubuntu which would help you to visualize relative sizes of files and folders. The program is called Baobab a.k.a. Disk Usage Analyzer and I believe it is installed by default:

Update: Out of curiosity, I downloaded Nautilus sources and spent a few minutes browsing around trying to see how it is formatting file sizes. Indeed, in nautilus-file.c there's a function:

static char *
nautilus_file_get_size_as_string (NautilusFile *file)
{
    ...
    if (nautilus_file_is_directory (file)) {
        ...
        return format_item_count_for_display (item_count, TRUE, TRUE);
    }
    ...
    return g_format_size (file->details->size);
}

And if you check the documentation for g_format_size, it says

  Sizes are rounded to the nearest size prefix (kB, MB, GB) and are
  displayed rounded to the nearest tenth.

So, as you can see, Nautilus is hard-coded to display items count for directories and file sizes rounded to the nearest prefix for files.

(as a side note - if you try Baobab, you'll see that scanning the full disk takes quite some time. This explains why it would be impractical to display cumulative directory sizes in Nautilus - this would slow down the whole thing quite a lot)


There are other answers to getting a Black Screen

Instead of of creating an image from your drive, I would start with simply downloading the iso and running a fresh install from within VirtualBox and seeing if that works.


grub2 (actually burg) can't see partitions on GPT external hdd

Fixed it, the reason is quite silly. You need the line insmod part_gpt so that it recognises the GPT. I've never seen this anywhere on the interwebs.


New ubuntu user with 18.04.3 systyem OS 32-bit

32-bit and 64-bit are different architectures, so a re-install is required.

*I've also assumed you mean x86 (i386/i686 32-bit) moving to x86_64 or amd64 (64-bit), and not ARM 32-bit to 64-bit move, or PowerPC 32-bit to 64-bit, but same would apply - you need to re-install*

You should backup your data and then re-install.

Your user settings, and user files will work without change once the new system is installed. You should replace your existing system, but do not select an option that formats unless you've safely backed up your data.

Myself I'd use Manual Partitioning or Something else options to ensure you don't format, which will

take note of your installed (added post-install) packages
erase system directories, and install system
re-add back (if available) your additional packages
request you to reboot

You've tagged 'intel', which is amd64 for 64-bit.  The x86 architecture was created by intel; but intel tried to move the market to an incompatible 64-bit format (ia64), but market forces wanted compatibility, so AMD's x86_64 compatible processors won out. ia64 is now a historical footnote, and amd64 applies to AMD or Intel 64bit x86_64 cpus.


I suggest that you use mkusb for this purpose. It wraps security around dd, and helps you get things right. There are menu options to wipe the first megabyte (which is often enough), or the whole device (which is slow, but might improve the write speed), or restore the drive to a standard storage device (automatically).

If mkusb fails (and you have checked that the 'lock microswitch' is not 'on', and no other process is locking the device) the drive is probably 'gridlocked', which is the first stage in the failing process. The next stage is that the drive is completely dead.

To be sure, it is a good idea to reboot the computer to get things clean and nice (and kill processes that might disturb what you want to do). You should also disconnect all other USB devices and memory cards (if possible). Then try again.

See the following links,

help.ubuntu.com/community/mkusb

phillw.net/isos/linux-tools/mkusb/mkUSB-quick-start-manual.pdf

Pendrive lifetime


Ubuntu Laravel storage/logs/cron.log permission denied

Since the directory permissions allow writing (file creation) for the owner and group, add yourself to the www-data group with

sudo adduser $USER www-data

The new group membership will take effect at the next login.


Problems on deleting a partition from USB key and format it in fat32?

You can do this by zeroing the entire flash drive, using dd

1) Run disks to get the device identifier, for example '/dev/sdg', then close disks.

2) From a terminal run this command

sudo dd if=/dev/zero of=/dev/sdg

This will write zeros to the entire flash drive, clearing it completely.
Be very careful to use the correct device identifier. If you use the wrong one you will erase one of your hard disks. This is a fate you would not wish on your enemies.

This will take quite a long time to run. You can check on the progress as follows:

Open another terminal and type the following

2.1) ps ax | grep /dev/zero

The first number is the pid

2.2) sudo kill -USR1 pid

The progress will be displayed in the first terminal.

3) When complete, run disks again, select the zeroed flash drive and format a fat partition.


It's a distribution mechanism for OpenStack on Ubuntu Server LTS releases.

Canonical’s Ubuntu Cloud archive allows users the ability to install newer releases of OpenStack on Ubuntu Server 12.04 LTS (and the dependencies) as they become available up through the next Ubuntu LTS release (presumably 14.04). Bug processing and patch contributions will follow standard Ubuntu practice and policy where applicable.
Canonical commits to maintaining and supporting new OpenStack releases for Ubuntu Server 12.04 LTS in the Ubuntu Cloud archive for at least 18 months after they release. Canonical will stop introducing new releases of OpenStack for Ubuntu Server 12.04 LTS into the Ubuntu Cloud archive with the version shipped in the next Ubuntu Server LTS release (presumably 14.04).
They will maintain and support this last updated release of OpenStack in the Ubuntu Cloud archive for 3 years, i.e. until the end of the Ubuntu 12.04 LTS lifecycle.

Sources:

ServerTeam/CloudArchive - Ubuntu Wiki
http://blog.canonical.com/2012/09/14/now-you-can-have-your-openstack-cake-and-eat-it/


how can I resize an animated GIF file using ImageMagick?

first run:

convert do.gif -coalesce temporary.gif

then

convert -size <original size> temporary.gif -resize 24x24 smaller.gif


NTFS Drobo External HDD not mounting properly

Although fsck can repair some of the damage done to NTFS, it is not as good as the built-in Windows CHKDSK so run that first on a Windows machine:

CHKDSK /F /R /B

As you're running 18.x, you have the latest ntfs-3g driver installed, so use all of the advanced options in the mount command:

rw,inherit,permissions,streams_interface=windows,windows_names,compression,norecover,hide_dot_files,hide_hid_files,big_writes

and definitely do not force anything.

Having said the above, once you have it running, I strongly advise you to:

get another external NAS of the same size
format it using a modern FS like ext4 or btrfs
mount that one Read-Write
mount the NTFS one Read-Only
copy the files over as and when you need them to become R/W

Finally when all files are copied:

Reformat the old one and use it to make rsync or borg backups of all your data.


How to use the cat command to find a specific word in a textfile

You can do it by grep. You do not need cat for that.

grep -w war file_name

You can use cat too, if you like

cat file_name | grep -w war

but it is longer.


Shell Commands for System Administration, and gudie to Vi editor

there are very many that i don't even know some but the basics can be gotten
Here download ubuntu guide to terminal usage  or download this simple pdf version
from another source and get started

Please be carefull when testing these commands


Missing Settings Directory in Whisker Menu

Yes according to this bug, I added following line in: /etc/xdg/xdg-xubuntu/menus/xfce-applications.menu (from this revision)

<Menu>
        <Name>Settings</Name>
        <Directory>xfce-settings.directory</Directory>
        <Include>
            <Category>Settings</Category>
        </Include>
        <Exclude>
            <Or>
                <Filename>exo-mail-reader.desktop</Filename>
                <Filename>exo-web-browser.desktop</Filename>
            </Or>
        </Exclude>

        <Layout>
            <Filename>xfce-settings-manager.desktop</Filename>
            <Separator/>
            <Merge type="all"/>
        </Layout>
    </Menu>

Now Settings Directory is Available:

Thank-you to @BrunoNova for co-operation by comments


Sounds like you maybe don't have the quickly-widgets package installed.

sudo apt-get install quickly-widgets

Then, e.g. following this video http://www.youtube.com/watch?v=urwBBlYhaUU&feature=player_embedded, the imports seems to work fine.

As far as docs go, the best I could find is using pythons internal documentation system.

from quickly.widgets import text_editor
print text_editor.__doc__

Module for the TextView widgth wich encapsulates management of TextBuffer
and TextIter for common functionality, such as cut, copy, paste, undo, redo,
and highlighting of text.

Using
#create the TextEditor and set the text
editor = TextEditor()
editor.text = "Text to add to the editor"

#use cut, works the same for copy, paste, undo, and redo
def __handle_on_cut(self, widget, data=None):
    self.editor.cut()

#add string to highlight
self.editor.add_highlight("Ubuntu")
self.editor.add_highlight("Quickly")

#remove highlights
self.editor.clear_highlight("Ubuntu")
self.editor.clear_all_highlight()

Configuring
#Configure as a TextView
self.editor.set_wrap_mode(Gtk.WRAP_CHAR)

#Access the Gtk.TextBuffer if needed
buffer = self.editor.get_buffer()

Extending
A TextEditor is Gtk.TextView


How to change Layout Switching shortcuts separately?

I tried it myself in Settings -> Keyboard Shortcuts -> Typing and can confirm your observation. Somehow the UI makes the previous shortcut depend on the next shortcut. Not sure if it's a bug or a feature.
OTOH, does it matter much? I mean, if you don't want to use the previous shortcut, then don't. You don't really need to disable it, do you?
Otherwise, if you really want to do it, you can first set the next shortcut and then run this command:
gsettings set org.gnome.desktop.wm.keybindings switch-input-source-backward "[]"


When you try to mount the volume you should be prompted for a password.
You need to enter the correct password that you set up when you initially set up the encryption.
If you don't remember the password, you will not be able to decrypt the volume. That's the whole point of encryption!  If you do not know the correct authentication, you will need to delete the partition or format the disk to be able to use it again.


Can I scale out the mysql charm instead of adding another database?

The MySQL charm supports replication.  It's a little non-intuitive in that you're not really adding units to the primary service. Instead, you're adding slaves.  Here's one way to do that:

juju deploy mysql masterdb
juju deploy mysql slavedb -n3
juju add-relation masterdb:master slavedb:slave

and then relate it to services like MediaWiki that support MySQL read-only replicas:

juju deploy mediawiki -n8
juju add-relation masterdb:db mediawiki:db
juju add-relation slavedb:db mediawiki:slave
...

The charm doesn't currently support any master-master replication.


Second monitor goes black after selecting Ubuntu in the GRUB menu

I discovered a way to workaround this problem.
Basically what I did was to boot with nomodeset option active in the grub. After that the black screen appears but i was able to acess tty and reboot my computer. The following boot process was normal even with an external monitor connected.


ERROR: 32-bit Linux Android emulator binaries are DEPRECATED

Open a terminal and run

sudo android avd -force-32bit

That should start it in 32bit mode

The 32bit version of adv is no longer supported, a 64bit OS is highly recommended for this due to 32bit memory limitations, there may be complications.


I had same issue on Ubuntu 18.4 LTS.

Cron kept old version of my script and didn't seem to see the script was updated.

Solved this by doing sudo service cron stop and then sudo service cron start.

sudo service cron restart didn't do the trick.


os-prober and update-grub can't see/find working Windows install

I have had the same problem:
Windows 7 and Linux (Slax with Grub2 and Debian in my case) and os-prober didn't recognizes the Windows partition when I used update-grub; Windows was left out.

I repaired the problem. First I tested adding the entry for Windows 7 manually to /boot/grub/grub.cfg (update-grub overwrites this file whenever it is run, so changes made to it are not permanent).

I rebooted and Windows 7 appeared in the menu and booted ok, aside from this error appearing:

error: no suck device: xxxxxxxxxxx (disk ID)

When this came up, I pressed Enter and Windows booted fine.

I investigated the execution of the os-prober command and others scripts involved in the process of recognizing OS and I test the output of

sudo /etc/grub.d/30_os-prober 2>/dev/null

Windows is not listed. I opened Dolphin file manager to browse the Windows partition and searched for the UUID of the partition and replaced it in /boot/grub/grub.cfg to resolve the error.

I executed

sudo /etc/grub.d/30_os-prober 2>/dev/null

and Windows was then listed ok

I rebooted the PC, went to console, and executed

sudo /etc/grub.d/30_os-prober 2>/dev/null

and then Windows was again not listed.

I opened Dolphin, browsed the Windows partition, executed

sudo /etc/grub.d/30_os-prober 2>/dev/null

again and Windows was listed.

I executed update-grub and the GRUB menu is now ok.

I think os-prober needs the partition (in NTFS case, because the Debian partition always is listed) mounted before it can find it. I haven't found out why os-prober has this behaviour but the solution works.


Yes, I have several ideas. There are two other ways to display the file name for browsing images using Eye of GNOME Image Viewer, when the Unity global menu is set as "in the window's title bar" and "always displayed" in Ubuntu.

Method 1: Image Gallery

Go to View > Image Gallery (or press F9 key). The image gallery or horizontal thumbnail strip will appear at bottom of the window. Then, use mouse cursor to hover on one of the thumbnails.

A tooltip will appear somewhere near to the thumbnail image, depending on where you position the mouse cursor. The file name will appear in the first line of text with relatively large and bold font.

Method 2: Image Properties

Go to Image > Image Properties (or press Alt+Return keys). The image properties window will appear at centre of the image viewer window. The file name will be shown in the first line of text as Name: FILENAME.png in the window.

Better image browsing

For better experience to browse images, use Method 2 with the tiling feature in Unity desktop environment (a.k.a Aero Snap in Windows).

tile the image viewer window to the left side;
tile the image properties window to the right side;
or whichever side you prefer to see the image properties with file name

Another way to browse is to maximize the image viewer window, then place the image properties window at any corner of your workspace (you can put aside the image properties window for a moment whenever it disturbs your viewing).

Either way, it is important to give focus on the image viewer window.

Then, use ← or → keys (left or right arrow keys) to navigate the images. The image properties window will always stay above the image viewer window, such that file name is always visible. Else, you can click on "Previous" and "Next" buttons, should you prefer clicking (I don't).

Disclaimer: This answer intends to provide clever workarounds, without having to install any additional packages or tweaking hidden settings. That being said, these workarounds do not solve the original problem that Unity desktop environment had introduced by having such settings.


GRUB command prompt instead of normal boot for Windows 10 after deleting Ubuntu partition

Using the LiveCD, start gparted and temporarily remove the ESP flag from the EFI partition so you can mount it. Mount the EFI partition and delete the folder /EFI/Ubuntu. Use gparted to reset the ESP flag, and reboot. The EFI firmware should recognize the change and set Windows to boot.


How to find application that wants access to private key

Gnome keyring uses these files listed with ls:

ls /etc/xdg/autostart/gnome-keyring-* ~/.config/autostart

where any of them that has

X-GNOME-Autostart-enabled=true

set. Those are all suspects for this popup.

Networkmanager is a likely culprit for fetching the wireless password. So is ssh if you have that installed.


How can I limit or restrict access to an application?

From my own experience restricting access to computer games is one of the most challenging tasks in educating our kids. Of course we parents want them to use their computers mainly for school but this heavily conflicts with the kid's intentions. They will hate us for giving them hardware usable for school only.

And of course we also want them to learn how to use their computer in a sensible way, including how to use it not only for work but also for leisure. This includes gaming and watching videos.

Unfortunately, well maintained and working parental controls to restrict the kid's computing is almost non-available for Ubuntu. Another major issue is that as soon as they are smart kids all measures we took become in vain. They will always find ways to overcome our restrictions, in case they are really smart without us even being able to notice.

Any blocking software or PAM-restrictions running on the kid's computer will be temporary only, and may sooner or later be overcome very easily. Therefore we decided to let the password-protected router do the job, where physical access can be controlled much easier.

So what we do here to somewhat limit gaming at the moment is a combination of all of the following:

Talk to them to educate them how and when to use computers for leisure, and when to use them for school. This is a constantly ongoing, rather tedious process leading to endless discussions and arguments. But it is what we feel is the only thing that will last in the long term.
No administrator permissions on their account. This is a temporary thing. We do know that they will be able to put themselves in the sudo group sooner or later. The plan is that they will ask us for that rather than making this in hiding.
Make a contract for clearly defined computing times. They need to know what for and how long they are allowed to use their machines. They need to learn how to split up this time for school and for leisure.
Hard-block all internet during sleep hours.

To ease fulfilling the contract on computer usage for both, the kids, and us we installed the following restrictions:

Use a password-protected router that allows restriction of internet access on a combination of a hardware (MAC) and a time-table basis. As long as they don't know about MAC-spoofing this will work quite well. It will also restrict access through their smart phones and tablets. This of course won't work if there was an open wireless network in your neighbourhood.
Install an SSH server on the kid's computers to pull the plug in case they got lost in their own intentions. This is for emergency cases we are glad we had not needed much.
Installed a DNS blacklist (through the router, not the computer!) which should block access to the worst.

Blocking internet access will effectively disable gaming if that game needs internet access such as Steam, Minecraft, or other gamig servers. It will however be of no effect for games running off line.


fallocate: fallocate failed: Text file busy in Ubuntu 17.04?

Creating a SWAP partition in Ubuntu, Linux Mint and derivatives

METHOD 1: Command-line Way from Terminal (Fastest way!)
STEP 1: First step is to check if by chance is there any SWAP partition already created in your PC:
sudo swapon --show

Enter your root password. If you see no output, it means that the SWAP doesn’t exist.
STEP 2: Next, let’s see the current partition structure of your computer’s hard disk:
df -h

STEP 3: As heynnema commented, before you start the changes disable the use of swap:
sudo swapoff -a
STEP 4: Now it's time to create the SWAP file. Make sure you have enough space on the hard disk. It is a matter of preference in how much SWAP size you need.
My suggestion is: If you have a maximum of 4GB of RAM I would suggest putting twice the RAM for the SWAP (8GB for SWAP). For PCs with more than 4GB I recommend the same number of RAM for SWAP plus 2GB. Example: In my case it's 8GB, I put 8GB + 2GB, totaling 10GB for SWAP. But you may feel free to make your choice.
sudo dd if=/dev/zero of=/swapfile bs=5M count=5120 status=progress

STEP 5: SWAP file is now created. Let’s give root-only permissions to it.
sudo chmod 600 /swapfile

STEP 6: Mark the file as SWAP space:
sudo mkswap /swapfile

STEP 7: Finally enable the SWAP.
sudo swapon /swapfile

STEP 8: You can now check using the same swapon command to check if SWAP is created.
sudo swapon --show

STEP 9: Also check the final partition structure again.
free -h

STEP 10: Once everything is set, you must set the SWAP file as permanent, else you will lose the SWAP after reboot. Run this command:
echo '/swapfile none swap sw 0 0' | sudo tee -a /etc/fstab

Finished, now exit the terminal!
You can check SWAP status on System Monitor utility.

METHOD 2: GUI Way using GParted
If you want to go directly through the graphical interface, enter the reference link below that is well explained.

Reference:

https://www.fosslinux.com/1064/how-to-create-or-add-a-swap-partition-in-ubuntu-and-linux-mint.htm


I have had a little NAS attached for music and film streaming for over a year with only the occasional problem generally because the NAS decided it needed a (sleep). The solution I found which has worked through 9.10 - 10.10 is detailed here.

Mounting Windows SMB File Shares Using Cifs

its a bit of an old post but it still works for me probably the most important part is adding the package smbfs as without this (which isn't installed by default) fstab wont be able to mount the shares.

Hope this helps


ldconfig ignores some files under /usr/local/lib/

TL:DR: Use a version (or build) of the program that supports the installed library version, if possible.

As bodhi.zazen says, it's hard to know quite what's going on without the specific exact commands you ran and the output. However, foo.so.0 and foo.so.1 should not be expected to be compatible.

To make a program compiled to use major version 0 of a library work with major version 1, it's advisable to rebuild (recompile and relink) the program. Furthermore, the interface a library provides to programs may change, and often does change, across major versions, so this is only sometimes practical.

Usually it is instead better to install a newer version of the program that supports the library version you want to use, if possible.

Alternatively, if you can install the old version of the library alongside the new one, that may also get the program to work. (If you're sure no other program uses the currently installed version of the library, then you could uninstall it before installing the old one. If it's provided by an Ubuntu package then you would do this by uninstalling that package. Different major versions of a library often do support being installed at the same time, though.)

In cases where you cannot installed the library version the program needs and you're willing to accept serious instability and unpredictable behavior from program, it's occasionally possible to get it to work with the new library by making a copy, naming it like the old library, and editing the version information inside it with a hex editor. I have done this before, but I have never seriously relied on software that was made to work in this way, and you shouldn't either.

This answer is deliberately general. Without more details about what program needs the library, how the program is (or can be) installed, and what versions of the library it supports, it's probably not possible to give more detailed advice.


Facing Login Loop in Ubuntu 20.04 Focal Fossa

I had this problem and tried all the things you did. The culprit turned out to be a very long environment variable. My LS_COLORS env var was over 9000 characters long as is was generated from a dircolors database. As soon as I removed it I could log in again. In /var/log/syslog I was getting a segfault in libpcre.so.3.13.3. That env var must have been causing gdm to crash.


The speed of syncing between computers may vary based on the size of your files, how active our servers are, and how fast a connection you have. I have a fast connection and files pretty much begin sync within a few moments.

Lets say Computer A is one computer and Computer B is the one that is not syncing.
Is there any activity in the logs of Computer B? Is is connected, receiving messages from Ubuntu One?


.htaccess is not visible in /opt/lampp/htdocs

It is very simple! I am such a newbie. Here it is

Go to the folder, and press CTRL + H, and there you have it.


"Files" is the user-oriented name for the package Nautilus. Or to be precise: for whatever your default file browser is. You could change it to e.g. Nemo.


Lenovo B560 with Ubuntu 16.04 can't discover my wifi

Try this:

sudo apt-get remove --purge bcmwl-kernel-source

Reboot and now tell if brcmsmac is loaded:

lsmod | grep brcm

Source: link


Why my shell script doesn't open the terminal?

Run the terminal from the script.

#!/bin/bash
xterm -e sudo apt-get install vlc -y

Other terminals might have a different way how to run a command than -e.


Why does my battery drains fast with Ubuntu in sleep more?

The reason is that you have set the settings of When Lid Is Closed to Suspend in Ubuntu

Lets understand what Suspend means and what Hibernate means-

Suspend -

Suspend means to save the state of your machine to the RAM of your computer.

In this case,RAM is volatile memory which requires power to function.And thus it uses battery.

When you resume from Suspend,it is quocker than resuming from Hibernate

Hibernate -

Hibernate means to save the state of your machine to the HARD DISK/HDD/SDD of your computer.Now,anything saved in HDD/SDD does not need power to stay there.Thus no power is needed.

Resuming from Hibernate* is slower than resuming from Suspend

So if you want your PC to act same as it does in windows when the lid is closed,

1.Go to System Settings

2.Select Power

3.In the When Lid Is Closed menu,select Hibernate


Audio from speaker on PC not workin during Google+ Hangout 12.10

One workaround is going to Sound Settings -> Input and changing the selection to anything and back to your usual microphone. That solves the echo for me, but the fix is not persisted and you'll have to do it again if you restart your computer.


I had the same problem. somewhere I found that we need to edit wifi network we are connected to and add 8.8.8.8 as dns. After that I was able to get Internet access.


Mouse pointer hides sometimes since upgrade

FYI, doug's response here seems to have solved the problem for me. Several hours now with no issue. Using Synergy heavily as well, which was always a sure way to make it vanish.

The gist: gsettings set org.gnome.settings-daemon.plugins.cursor active false


Triple monitor setup with an ATI Radeon 4200?

Sorry, based on the information in your question your card doesn't support three monitors.

The AMD/ATI technology for driving more than two monitors from the same card is called Eyefinity, but it is only supported on certain cards, see AMD's Eyefinity FAQ.

In brief, you need

one of the Radeon models listed in the FAQ (all in the 5000 and 6000 series)
and the card must have a DisplayPort connector.

The DisplayPort must be used for the third monitor.

In addition, AMD does not officially support Eyefinity on Radeon cards for Linux yet. Drivers exist, so with the proper combination of cards and monitors it can be made to work, but there are some limitations.

See also the question 3-monitor graphics on Linux on superuser.com.


Making the installed packages in the WSL portable

In your case you can install the Apache Airflow via python pip in your WSL subsystem and then copy all the files in the ~/.local/lib/python[your_python_version]/site-packages and then you can zip it in order to transfer to another computer.

But note that if the Ubuntu version in the WSL subsystem of the second machine is different , that might cause some problems. Just make sure that the python's minor version is the same since the compatibility between the different minor versions of python isn't guaranteed.

You might need to install python-pip first.

Note : I haven't do it myself but it should work at least on the paper.

If anybody has a better solution , I'm glad to hear.


That problem could be solved for me with Chrome's --touch-devices command line parameter.

Determine X's input device id in a console by

xinput list

leading to

google-chrome --touch-devices=10

on my system.

To make Chrome always use this CLI flag, see:
How to set CLI flags for Google Chrome?


How do I open a folder using a bash script running terminal

You need to use the -e option of xterm, and cd to go to the desired directory e.g. cd /foo/bar/. The tricky part is that the command will be run in a non-interactive session of your login shell, so if you want to keep a shell session open, tack the desired shell directly afterwards e.g. opening bash on that directory:

xterm -e 'cd /foo/bar/ && bash'

If your goal is to run an one-shot command, then just use the command directly (preferably use absolute path if unsure), no need to spawn a shell.


I believe the answer you are looking for can be found here.

That link shows all the files and locations after they are installed.

Also, after the gtk-3-examples are installed, you can access the demo by typing in

gtk3-demo

Other nice tools are

gtk3-icon-browser

and

gtk3-widget-factory

Hope that helps!


Run in the terminal:

blueman-manager

When the connections list appears you may use TAB button and arrow keys to navigate.


Format option not available in 11.10 as in 10.10?

I use  Disk Managment that you can  find from the Dash (Dash > Disk managment). From there you can do what you want


Random freezes (including during attempted install)

UPDATE
After downloading the Windows 10 ISO, I found the exact same behavior occurred during Windows 10 setup - it hung a few minutes after booting.
Intel are replacing it under warranty (it was purchased in December 2018).
In case anyone else stumbles across this, my advice is the following:

Test all user-installed hardware issues - remove / swap / test memory, HDD, etc
Test the power supply (try a new power adapter)
Test the software - try a different OS, live CD, etc

Once you've tested and passed all of those, contact Intel for a warranty claim. I was able to explain what I had tested and they were able to commence the warranty process.


Hp Zbook 17 G3 Mobile workstation with Ubuntu 14.04.3 LTS installation problem

The problem is I have installed win 7 on it (corporate requirement)

I doubt that this is anywhere related to your problem nor do I believe that having a lazy or understaffed IT department can be described as particularly corporate attribute. Choose another company to work for if software necrophilia in conjunction with new hardware is a problem for you.

  A quick reply or help is highly appreciated.

Tell us more about the interesting and not the superfluous things. You already were on the documentation page on the HP site, that link would have been useful because you're probably looking at the wrong page or you interpret the data in the wrong way. (Which release and which kernel of "Redhat Linux"? HP has staff allocated to work on providing support for major Linux distributions internally to their users – yes I had access to that part of their Intranet – which is more like what you should be looking for than an official product support statement, unless you have a support contract with HP. In that case you should do as they say and file support request with them where you don't agree with the service, not here.) A reference to what you mean with ROS and other acronyms that may be non-unique product name should also be good practice, because I see XY problems and answers everyday.

You're asking for a pinpoint accurate technical answer, leave the whole story telling thing to marketing please.

  I wanted to know how to solve these issues and also if Ubuntu is releasing a version that has all the drivers for this machine.

14.04.4 with the 15.10 kernel would be more appropriate than the older release with the 15.04 kernel regarding in kernel drivers (see: How can I upgrade the Ubuntu LTS kernel to newer?). For a laptop a model that's apparently released in 2016 you shouldn't use a kernel and related software components released in early 2015, though. A good idea is to try the development release on new hardware when it's only a few weeks away from the final release date.

If your question was about proprietary drivers than that's a bit different and I'm happy to not have to use these.

  I am having problems regarding the booting of Ubuntu and graphics issues.

More details please. Screenshots, photos, logs and everything that helps to describe the exact behavior you are seeing. Please keep in mind: one problem = one question. Don't put two or more problems in one question, that makes this site less usable for everyone. Also note this site is not a bug tracker, Launchpad is.


Connecting Second Monitor to Laptop via VGA Cable - Screen detected, but screen says no signal

There was something stuck in the VGA port on my laptop, though it was almost impossible to see. I now have a laptop case to avoid the same problem in the future.


How to synchronize multiple mail (thunderbird) accounts?

The simplest and best solution is configuring all your email clients to use IMAP, if your mail service supports it.

If IMAP isn't supported by your email service, you have a few options:

Store your Thunderbird profile in Ubuntu One.
Store your Thunderbird profile on the server, and share it via SSHFS/CIFS/NFS. It's usually desirably to do this as part of a more general SSO solution.
Synchronize the Thunderbird profiles with a file sync utility such as Unison.