20.04 - Google Chrome Display Glitches after wake up

I tried the enable-vulkan option which worked but I ended up having a lot of lag. I found another option that is to add --use-cmd-decoder=validating --use-gl=desktop when launching.
I.e. I copied the /usr/share/applications/google-chrome.desktop to ~/.local/share/applications and edited the Exec line to add those options.


Are there any options of bash with which it is invoked?

Usually, no, the terminal does not pass any options to bash. bash does, however, assume a set of default options depending on how it was invoked. From man bash, section INVOCATION:

An interactive shell is one started without  non-option  arguments  and
without the -c option whose standard input and error are both connected
to terminals (as determined by isatty(3)), or one started with  the  -i
option.   PS1 is set and $- includes i if bash is interactive, allowing
a shell script or a startup file to test this state.

An interactive shell further activates other options.
Further some defaults apply based on the invocation name (sh vs bash). Reading on (section on set):

-h      Remember  the location of commands as they are looked up
        for execution.  This is enabled by default.
-m      Monitor mode.  Job control is enabled.  This  option  is
        on  by  default  for  interactive shells on systems that
        support it (see JOB CONTROL above)
-B      The  shell performs brace expansion (see Brace Expansion
        above).  This is on by default.
-H      Enable !  style history substitution.  This option is on
        by default when the shell is interactive.

Combined, simply invoking bash on a terminal will enable these options.

You can confirm this by checking the value of the $- special variable:

$ echo $-
himBH

An additional option that maybe set is if your terminal is set to start login shells. In that case -l is explicitly passed by the terminal as an option.


What's the difference between dash and dock?

It is terminology. In default GNOME Shell, the "Dash" is the bar with favorites and running applications that appears in the Activities Overview. It is only visible in the Activities Overview, which you see when you click "Activities" in the top bar, or hit and release the Super key.
A GNOME Shell extension, "Dash to Dock" can turn that Dash into what from then on is referred to as a Dock on your desktop. Then, it is directly available on your desktop, and thus behaves much more like a dock in for example MacOS.
In a default Ubuntu install, a custom GNOME Shell extension, Ubuntu Dock, is active. That is actually derived from "Dash to Dock" and uses the same configuration settings. So you already have the "Dock" instead of the "Dash", and do not need to install an additional extension for that.


How do I get Ubuntu 12.04 to detect my monitor correctly?

Same issues here. I have an intel integrated graphics. Doesn't detect my display, lets me get 1024x768 res when I should be able to get 1680x1050. They have seriously messed this one up and I dont think they'll fix it as I've been having these issues for over a month. There's a dirty fix it do every time i turn on my computer but it causes lots of errors and crashing but it gives me the right resolution i suppose.. Think I'm going to switch to Winblows tonight, it's more stable and these issues just don't exist.

$ xrandr --newmode "1680x1050" 146.25 1680 1784 1960 2240 1050 1053 1059 1089 -hsync +vsync

$ xrandr --addmode VGA1 1680x1050

$ xrandr -s 1680x1050


No permission to automount external HDD using ntfs-3g

Found an answer that lets me not edit my fstab to get what I want.  Since my disk gets automounted, I added a rule to my udev that told the automount to do something special upon plug-in (that I don't really understand).  But now my disk gets automounted with all files executable.  I created a file /etc/udev/rules.d/99-usb-disks.rules and added:

ENV{ID_FS_TYPE}=="ntfs", ENV{ID_FS_TYPE}="ntfs-3g"

Source: http://ubuntuforums.org/showthread.php?t=1914416&p=11636662#post11636662

Still haven't found a way to get rid of my permissions error when I do use my fstab mod, though.

Thanks terdon for the help.


gedit default directory and .desktop file

https://bugs.launchpad.net/gedit/+bug/194904 and https://bugzilla.gnome.org/show_bug.cgi?id=504067 suggest this is NOT possible
2 comments noteworthy:

Gedit remembers the last folder where a document was saved, so I think this cannot be applied right now. Open the bug again if you think that the current behavior is not the one expected.
Regarding the first issue, he is right. Right after installation, gedit suggest the /home/$(USER)/ directory to save a file instead of /home/$(USER)/Documents. I think this should be changed (if it is actually not only a problem of Ubuntu).

The initial save location (ie. user home) is hardcoded into gedit
Gedit will remember a new save location and make that the default


Debugging not being able to see what I type in bash

First, you can fix this with

stty echo

(and, of course, man stty).

One of your scripts has a flaw, in that it turns off character echo, but fails to turn it on (in bash, via the trap buitin).

In the Early Days (1967), computer access was via remote terminals like the TeleType ASR-35 and KSR-33, at a speed of 110 Baud.

There were two ways of sending characters to the computer on the other end: Half Duplex, where characters were echoed locally, and probably sent to the computer; and Full Duplex, where characters were not echoed locally, but sent to the computer, which echoed each character back to the terminal, allowing verification.

Letting the computer (running Unix in 1970) know which way your TeleType was configured was done via stty -echo and stty echo (see man stty).

stty echo is included in stty sane. stty sane never hurts.

The Unix "tty" concept is still in use with your terminal today.


Is there an FTP client (GUI) that will let me search for text inside files?

You can use nautilus to connect to the server.
Goto Places → Connect to server → ftp

After connecting to it,you can see it in your nautilus.
You can search it like any other filesystem you can access.


Sound Input Works in Audacity but not in PavuControl

In Pavucontrol , "input device" tab,  you may have 2 devices: choose "built in analog", and check that "internal mic" is selected there.

Normally, the switching between internal/external mic is automatic  . If it is broken, you can try to plug an external  mic (or a headphone, just for the test)  in the mic jack, and see if "pavucontrol" input device change.

You can also try to test other profiles in pavucontrol "configuration" tab.

If it stills bad,  you can try to reset Pulseaudio config by copying and running this command in a terminal:

rm -r ~/.config/pulse; pulseaudio -k


Will Ubuntu Software Center add support for generating dynamic license keys?

The situation here is that some applications use user-details to create the license making it unique. For example, you might use the customers e-mail address as an input to the hash.

We've been asked for this feature a number of times so we're certainly aware of the need. However, each developer uses a different process to generate their licenses. Consequently, we'd either need to provide a system within Ubuntu (ie a library) or some sort of API integration within the Apps portal. Either of these would be complex undertakings.

So, for the moment it's going to be static licenses and we'll probably concentrate on mechanisms like e-mail notification.


Logitech MX Master 2s cursor speed very slow on Ubuntu 19.04

First solution :

We are going to change a value in a file.  Change the value 128 in the flowing file to 200 (temporary), or what ever value suits you.

sudo nano /sys/devices/platform/i8042/serio1/serio2/sensitivity

Once you found values you are comfortable with, make the change permanent using an Upstart job:

Now: **Create a new udev rule :**

Now we need to apply the settings during the system start. Therefore, press Alt + F2, type

gksu gedit /etc/udev/rules.d/trackpoint.rules

and hit Enter (this will ask you for your password). Then paste the following:

SUBSYSTEM=="serio", DRIVERS=="psmouse", DEVPATH=="/sys/devices/platform/i8042/serio1/serio2", ATTR{sensitivity}="220", ATTR{speed}="110"

Save the file and either reboot or run the commands above:

sudo udevadm control --reload-rules

sudo udevadm trigger

2nd solution :

you can also type in terminal (my prefered solution) :

sudo apt install xserver-xorg-input-evdev && sudo apt purge xserver-xorg-input-libinput && sudo reboot


Upgrade to 15.04: What happened to my gnome-terminal tabs?

If you want to know how to fix this problem, the new version has the option to open all new terminals in a tab. Go to Edit -> Preferences and then change "Open new terminals in: Window" to "Tab".


I just had the same problem with different hardware (samsung n130, 32 bit, Kubuntu 14.04, KDELibs 4.13.3) and could solve the problem with the following steps:

System settings > Workspace behaviour > Workspace
Global options for the Plasma Workspace, changed Workspace type from Desktop to Netbook
Log-off, remove DVD-drive, Log-in (successful, including KDE)
Workspace type had changed to Desktop
after system restart the problem is still fixed


In recent versions of ubuntu / debian I am modifying the file: /lib/systemd/system/mysql.service
ExecStart=/usr/sbin/mysqld --sql-mode=NO_ENGINE_SUBSTITUTION

Then:
systemctl daemon-reload
systemctl restart mysql

changes to *.cnf files do nothing


Will upgrading Ubuntu 10.04 to 12.04 change my files?

Your data will not be lost. Go for it. Use the update manager and upgrade.

It will take a little time though.


As a first step, to diagnose problems with suspend, you will want to look at details in the log-file /var/log/pm-suspend.log

If the log-file /var/log/pm-suspend.log doen not exist, just run sudo PM_DEBUG=true pm-suspend in a terminal window.  NOTE: This will suspend your computer, so you're probably going to see the problem again, however, the pm-suspend.log log-file should be there when you eventually re-start.

The file should contain a series of

[...] service [servicename] suspend suspend

statements (together with hook status messages & other useful stuff), followed by a series of

[...] service [servicename] suspend resume success

statements.

However, somewhere along the way, one or more of these will probably return an error and at that point suspend is inhibited. You may see a series of suspend changes being rolled back. To locate the problem you'd normally just need to identify which service call is throwing the error.

In this case, the log file doesn't seem to have any service [servicename] suspend resume statements, so as a next step, can you suspend the notebook again, and try to resume by pressing the power button. Give it a couple of minutes, and if it fails to re-start re-boot by holding the power button down for 5 seconds.  When you re-start, open a terminal and run dmesg | less. Please update the original question to include the output from dmesg | less.

I'd also suggest verifying that your swap-partition is correctly set, and in particular that it is at least at big as your installed RAM. This is a handy FAQ on Swap.

UPDATE: The output from dmesg | less that you posted includes the line:

[    1.197601] PM: Hibernation image not present or could not be loaded.

(line 574 in the file) Again, this suggests a problem with hibernation (suspend-to-disk), but if you're sure that your problem is actually with suspend (i.e. suspend-to-RAM) then that can't be it.  I also can't see any reported problems with your Intel/NVIDIA graphics.


Get the most recent complete installation DVD of Linux and Ubuntu

There isn't a "Professional" version of Ubuntu. When you download the ISO image from Ubuntu, you get a fully functional system with some programs by default, that includes:

Office suite
Image editor
Music player
Video player
Email client
Multiprotocol chat client
whatever you want from the repositories using Ubuntu Software Center

You can also select Portuguese before installing the system. When booting from the DVD/CD you can select the Language you want to Install the system from the very start. Just press F4 while booting, then select your preferred language.

If you missed the boot screen, you can select the language after you have hit Install Ubuntu:


How do I disable presenter console in Libreoffice 4

I think the easiest and cleanest way to proceed is to go to Tools/Options/Impress/General and disable the option "Enable Presenter Console".
NB: You must be in LibreOffice Impress for this option to show up.


12.10 is very old and out of date - you'd need to upgrade at least 3 times in a row just to get to a version that's current enough to be supported.

Instead, you should download a new CD image and install from that.

It will get you to version 14.04 or 14.10 with a lot less downloading.


Not sure if this is the same case or not but

make sure you are downloading the latest version from the site

http://storagemadeeasy.com/LinuxDrive/

there was an updated version to solve this issue with 13.10 .


Does/will Ubuntu One have a version control system?

This has been on our radar for a while now, yes.
We are going to approach releasing this incrementally (ie, probably expose un-deleting files first).

I don't have a release date for versioning, but it's something we're building towards. As soon as we set a date, we'll announce.


Low Graphics Mode Error after clean 14.04.2 LTS installation

Solution:

I solved it (meaning I haven't had the Low Graphics Error now for about 10 reboots) by installing drivers for my GPU (2x 280X AMD cross-fire). I've done this previously with no success, but I guess I then had tried some other things before installing the drivers that messed it up. To help others with the same problem I'll explain what I did in detail.

After a fresh installation of Ubuntu 14.04.2 LTS and reboot I got the Low Graphics Mode error.
I rebooted into Windows 8.1, went to AMD's website and downloaded the drivers for my GPU (Ubuntu 64bit in my case), and unzipped the folder to a 4 GB USB 2.0 stick.
I booted back into Ubuntu.
My USB didn't show up under /media so I had to manually mount it with the help if this site.

I ran sudo fdisk -l to see that my USB was under /dev/sdc (the only unit that had ~4 GB space on it) and that it was formatted as FAT16.
I ran sudo mkdir /media/external to create the folder for mounting the USB.
I ran sudo mount -t vfat /dev/sdc1 /media/external to mount the USB in the folder.

I ran sudo mkdir /home/john/amd_driver to create a folder on by Ubuntu system in my user folder to place the driver (I didn't dare to install it from the USB stick itself).
I ran sudo cp -r /media/external/fglrx-14.501.1003 /home/john/amd_driver to copy the driver folder from my USB to my user directory.
I followed the installer instructions (http:// support.amd.com/en-us/kb-articles/Pages/Catalyst-Linux-Installer-Notes.aspx) from AMD's website of how to install the driver (I had no previous driver so I skipped the first steps for uninstalling that)

I ran sudo sh ./amd-driver-installer-14.501.1003-x86.x86_64.run while inside the /home/john/amd_driver/fglrx-14.501.1003 folder, and followed the instructions.
The "Generate Distribution..." option did not work, so I chose the "Install Driver..." option instead.
I ran /usr/bin/aticonfig --initial to configure the newly installed driver.

After rebooting, everything has worked since then.


Dash doesn't launch Gedit at the first try

I can confirm it, it's very annoying.

This was reported as bug #827414 several month ago and is fixed in 12.04 (Precise), don't know if there will be backport to 11.10 (Oneiric).

You can use very simple workaround: run gedit always with command line switch --standalone. Here is my script for that, it's slightly adapted from comment:

$ sudo mv /usr/bin/gedit /usr/bin/gedit.bin
$ sudo bash -c 'echo -e "#"\!"/bin/bash\n/usr/bin/gedit.bin --standalone \"\$@\"" >/usr/bin/gedit'
$ sudo chmod 755 /usr/bin/gedit

Hope this helps.


How to auto login to Ubuntu Server after installation using preseed file

Resolved this by adding script which contains the same logic as mentioned in above link. This script is then called in preseed file.


Appearance does not change on switching the theme

Install dconf-editor if you don't have it, and then go to

  org.gnome.settings-daemon.plugins.xsettings

and check "active." One thing I've also noticed when this happens is that the media keys stop working: enable org.gnome.settings-daemon.plugins.media keys. There also might be some more plugins you should enable.

Problem cause: when unity-greeter is run (by the lightdm --test-mode command in my case), it disables a lot of settings-daemon plugins that have to be manually reenabled.

I got all of my info from this thread: http://ubuntuforums.org/showthread.php?t=1861476


help needed to install nvidia driver on ubuntu 13.04 64 bit

Replace the links you needed with those you find here: https://launchpad.net/~canonical-x/+archive/x-staging


How to install sublime text for typescript in ubuntu

You dont have to download a separate version of sublime text to get typescript support.You only need to install the package manager from here. And then after opening sublime text press Shift +Ctrl+P type install there select install a package from the drop down and then search for typescript to install typescript.
You can follow this tutorial typescript support for sublimetext3 https://www.youtube.com/watch?v=2iRHiDgOsJA


The key fingerprints are on https://help.ubuntu.com/community/VerifyIsoHowto

Currently they are

C598 6B4F 1257 FFA8 6632  CBA7 4618 1433 FBB7 5451
8439 38DF 228D 22F7 B374  2BC0 D94A A3F0 EFE2 1092

You can retrieve them both with:

gpg --recv-key 843938DF228D22F7B3742BC0D94AA3F0EFE21092 C5986B4F1257FFA86632CBA746181433FBB75451

If you're already on an Ubuntu system the package ubuntu-keyring has these keys in /usr/share/keyrings/ubuntu-archive-keyring.gpg which you can import with gpg --import /usr/share/keyrings/ubuntu-archive-keyring.gpg.


can't access my Ubuntu server after I changed the SSH port

the problem was from the firewall of the network in my university
it was working with 22 but they block any other port because that i couldn't also enroll to the (access console ) of digitalocean
what i did is i change the internet connection and i logged to my cpanel of digitalocean and i changed the port to 22 again


How to copy a driver into a directory for Intel ax200 wireles device

lib/firmware is only valid if you did a cd /before it. Otherwise the command needs to be:

sudo cp /home/alberto/Downloads/iwlwifi-cc-46.3cfab8da.0/iwlwifi-cc-a0-46.ucode /lib/firmware

2 alterations:

sudo
a /in front of lib/firmware


You can connect from inside your network?

You can try an nmap scan from outside to see if the port forwardings are
working properly.

install via

sudo apt install nmap

run scan via

sudo nmap -A your-public-ip-address

Than you can try to connect via smbclient using this command:

install via

sudo apt install smbclient

(-L)ist shares via

smbclient -L your-public-ip-address


Is there any issue with LAN-card in ubuntu?

Short Answer: Yes

However, there may be incompatibilities. The worst that can happen is that the LAN card doesn't work due to driver incompatibilities. And, this is rather rare and is almost always correctable. You are most likely safe.

To test it, boot a Live Ubuntu session. If it works there, it will work on an install.


Touchpad right click not working - How to enable touchpad buttons and keep two finger click?

On my Jetson Nano with Ubuntu 18.04, I ran into a similar problem connecting my Logitech TouchPad - this is what I did to make it work for me...

In a terminal window use the xinput cli - first find the id of your touchpad:

xinput list

In my case, the touchpad shows with ID 10; now get the setting for the touchpad:

xinput list 10

In my case I see: libinput tapping enabled (360): 0, meaning that the command id is 360 and the tapping is not enabled - so let's enable it:

xinput set-prop 10 360 1

After this, I can tap slightly with one finger (not a deep press) to left-click, with two fingers to right-click and with three fingers to middle-click.

You can try other settings as well, for example I also set Natural scrolling (the content moves with the swipe, not the scoll-bar) which is what I am used to.

xinput set-prop 10 286 1

Worked for me - hope it works for you too!


Ubuntu Installation in Asus Tuff Gaming FX505GD

If you want to wipe out Windows, it should be easy.
Boot with a LiveUSB, start gparted and create a new gpt partition table on your SSD. Then there should be no problems to install Ubuntu.
Intel RST is supported by Linux. The problems arise when Windows is install in some RAID mode and you want to keep it.
Recently I installed Ubuntu 20.04 and didn't even noticed that it was installed in RST mode.


Conneting PCs on Local IP, but on different subnet through Remmina

Do you really mean IP 10.11.15.16? (The one you can't connect to).
10.11.15.16 is on a different subnet than the other two.


Use following command in Terminal:

sudo passwd <user>

Replace <user> with the username whose password you wish to change.

This works because passwd suppresses all checks for length or entropy when you use it as the root user.

  Warning: if the target user has an encrypted home directory, this will
  cause problems!
  (see comments below)


Can a use a 32bit guest Ubuntu Virtual Machine on a 64bit host machine in a Virtual Box?

Yes.
The other way around also works but you then do need a 64-bit processor.
you can not execute a 32-bit file on a 64-bit system (or the other way around) without installing support for it. It is called multi-arch.

  I am getting an error everytime which tells me no such file or directory found even when the binary file is in the same directory in which I am in

That, in general, means the file is not an executable.

check with ls -l what the settings are for that file.

  So is it any problem with sharing of folders??

Executing from Microsoft filesystems is set when mounting the partition. So yes, this can be the cause.

check the mount options for the partition with more /proc/mounts.

If you need more information edit your question with at the least the results of above to checks to do so we can expand this Q+A.


Replaced screen for my laptop, now can't control brightness (16.04)

I mean, have you tried testing it with a different environment, where it's more likely to work out of the box (e.g. Windows)?
Maybe the new screen uses a different controller/firmware/driver, which is incompatible with that the laptop previously had (and expects).
I haven't yet had to replace a laptop on a screen, but at least on Hackintoshes (which might be a bad example, but I can't think of anything else) you usually have to do quite a bit of patching to get backlight control working, because the controller is simply something else than what the OS expects.


I need to convert ext2 filesystem to ext4 to prevent fsck every time I boot?

You'll have to do that from a live environment (launch from a Ubuntu DVD or pendrive). Before doing so, please check the filesystem:

sudo fsck.ext2 /dev/sda1

And then do your thing. You better also enable dir_index. You can read about ext4 features on Wikipedia. Do it:

sudo tune2fs -O dir_index,has_journal,uninit_bg,extents /dev/sda1

After doing that, try mounting the filesystem to see if everything is OK.

sudo mount /dev/sda1 /mnt -t ext4

Can you see the filesystem? Nice.

sudo ls /mnt

And that's enough to convert the filesystem. But you'll also need to change the file /etc/fstab for the operating system to mount the filesystem as ext4.

sudo gedit /mnt/etc/fstab

Change the second line to say ext4 instead of ext2:

# / was on /dev/sda1 during installation
UUID=14f577b8-xxxx-4124-88d3-c1d49eb41113 /               ext2    errors=remount-ro 0       1

And that's it. Save and exit. Don't forget to unmount the filesystem before restarting into your system again:

sudo umount /mnt


Your question has several answers here. However, reading the answers, it seems like there is a details missing, namely what your script (or mplayer) will detect as output.

If you do script -c myscript out.log, the programs run by myscript  will detect that their output is a terminal, so they might try to produce fancier output, involving hidden control sequences, like colors and cursor movements. The file out.log will contain those sequences, too.
If you do myscript 2>&1 | tee out.log, the programs in myscript will detect that their output is a file, so they might disable fancier formatting.


Ubuntu 16.04 Plymouth doesn't show splash screen at startup!

In 16.04, plymouth path was changed.

You need to edit the /etc/alternatives/default.plymouth file.

Under the script caption make sure the directory is exactly like this:

ImageDir=/usr/share/plymouth/themes/YOUR_PLYMOUTH_NAME/
ScriptFile=/usr/share/plymouth/themes/YOUR_PLYMOUTH_NAME/YOUR_PLYMOUTH_NAME.script


I downloaded Ubuntu 12.04 and I can't boot it from the USB

The short answer depends if you have UEFI or not.  If you do, and Windows 8 is setup using it, then you need the 64bit version.  Only 64 bit version currently has the UEFI secure boot capability, since only new computers support UEFI.

For more information take a look at UEFI


L2TP IPsec VPN client on Ubuntu Desktop 16.04

There seems to be a known issue about this.
Error message when starting network manager from Terminal:

$ nm-connection-editor
** Message: vpn: (strongswan,/etc/NetworkManager/VPN/nm-strongswan-service.name) cannot load legacy-only plugin


How to upgrade to Valgrind 3.10.0 on Ubuntu 12.04?

You can upgrade valgrind as follows:

wget http://valgrind.org/downloads/valgrind-3.10.1.tar.bz2
tar -xjf valgrind-3.10.1.tar.bz2
cd valgrind-3.10.1
./configure --prefix=/usr/local
make
sudo make install
ccache --clear


Start application as root (No command line)

In my opinion, one way is to create executable shell script and then using pkexec run Sublime Text. I think that you can move the .sh file to dash then... But I am no longer using Ubuntu, so I am not so sure about this.

Create empty file: touch run-sublime.sh
Edit file using your favorite editor e.g. subl run-sublime.sh
Paste this in file

  #!/bin/bash
     pkexec subl

Make script excutable: chmod +x run-sublime.sh


Request about description regarding cpuinfo

Ok, This Is a Community Wiki, so Everyone fill in the information that you know, and we can make this a general answer. We can start with the description of the flags.

Information from http://www.sungju.org/?p=519 :

  fpu Onboard (x87) Floating Point Unit
  vme Virtual Mode Extension
  de Debugging Extensions
  pse Page Size Extensions
      tsc Time Stamp Counter: support for RDTSC and WRTSC instructions
      msr Model-Specific Registers
      pae Physical Address Extensions: ability to access 64GB of memory; only 4GB can be accessed at a time though
      mce Machine Check Architecture
      cx8 CMPXCHG8 instruction
      apic Onboard Advanced Programmable Interrupt Controller
      sep Sysenter/Sysexit Instructions; SYSENTER is used for jumps to kernel memory during system calls, and SYSEXIT is used for jumps back to the user code
   mtrr Memory Type Range Registers
   pge Page Global Enable
   mca Machine Check Architecture
   cmov CMOV instruction
   pat Page Attribute Table
   pse36 36-bit Page Size Extensions: allows to map 4 MB pages into the first 64GB RAM, used with PSE.
   pn Processor Serial-Number; only available on Pentium 3
   clflush CLFLUSH instruction
   dtes Debug Trace Store
   acpi ACPI via MSR
   mmx MultiMedia Extension
   fxsr FXSAVE and FXSTOR instructions
   sse Streaming SIMD Extensions. Single instruction multiple data. Lets you do a bunch of the same operation on different pieces of input in a single clock tick.
   sse2 Streaming SIMD Extensions-2. More of the same.
   selfsnoop CPU self snoop
   acc Automatic Clock Control
   IA64 IA-64 processor Itanium.
   ht HyperThreading. Introduces an imaginary second processor that doesn’t do much but lets you run threads in the same process a bit quicker.
   nx No Execute bit. Prevents arbitrary code running via buffer overflows.
   pni Prescott New Instructions aka. SSE3
   vmx Intel Vanderpool hardware virtualization technology
  svm AMD “Pacifica” hardware virtualization technology
  lm “Long Mode,” which means the chip supports the AMD64 instruction set
  tm “Thermal Monitor” Thermal throttling with IDLE instructions. Usually hardware controlled in response to CPU temperature.
  tm2 “Thermal Monitor 2″ Decrease speed by reducing multipler and vcore.
  est “Enhanced SpeedStep”

processor   : 0 -

vendor_id   : GenuineIntel -  The vendor id is "GenuineIntel" this tells you that your processor is Intel.

cpu family  : 15 -

model       : 6 -

model name  : Intel(R) Pentium(R) D CPU 3.00GHz - The model name of the processor, you have a Pentium D that is the 3Ghz model

stepping    : 5 -

cpu MHz     : 2400.000 -  The Mhz of your processor.

cache size  : 2048 KB - how much cache your processor has

physical id : 0 -

siblings    : 2 -

core id     : 0 -

cpu cores   : 2 -

apicid      : 0 -

initial apicid  : 0 -

fdiv_bug    : no -

hlt_bug     : no -

f00f_bug    : no -

coma_bug    : no -

fpu     : yes -

fpu_exception   : yes -

cpuid level : 6 -

wp      : yes -

flags       : fpu vme de pse tsc msr pae mce cx8 apic mtrr pge mca cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm pbe nx lm constant_tsc pebs bts pni dtes64 monitor ds_cpl est cid cx16 xtpr pdcm lahf_lm -

bogomips    : 5983.43 -

clflush size    : 64 -

cache_alignment : 128 -

address sizes   : 36 bits physical, 48 bits virtual -

power management: -


"No space left on device" and "You don't have enough free space in /var/cache/apt/archives/."

If your Docker container is using DeviceMapper, Btrfs, overlay2, WindowsFilter, or ZFS Graph drivers, then you could do something like this when defining a container:
docker run -it --storage-opt size=500G torchy /bin/bash

Note: Be sure to change torchy to the proper container name.
This will allow to set the container’s root file system size to 500G at creation time. Just as with many virtual machine tools, you do not need to preallocate the space when defining it.
Caveats

When using DeviceMapper, Btrfs, WindowsFilter or ZFS Graph drivers, you cannot pass a size less than the Default BaseFS size (which is usually 10G)
When using the overlay2 storage driver, the size option is only available if the backing file system is XFS and mounted with the pquota mount option. Under these conditions, you can pass any size less then the backing file system size.

For more info, the docs are your friend


if you want to update the PATH only for your user, just edit your local bashrc

gedit ~/.bashrc

if you want to update the global PATH

gksudo gedit /etc/bash.bashrc


Quicker alternative to gnome-screenshot? (no animation!, quick!, no frills)

I used a program named scrot which is really lightweight.

I set up this in the Terminal

cd /tmp/
while true; do sleep 0.1s ; scrot; done

which will cause that (assuming performance allows) there is about 1 screenshot taken each .1s. (Almost like recording a movie :) ).

scrot saves the files (named with a timestamp) in the current directory. That is why cd /tmp is a good first step.

Anyhow there is no baggage, no animation... simply screenshot. I kind of like scrot.


Execute java from terminal and let it run even after the ssh session ends

Answer is in top 1 related question

How to keep processes running after ending ssh session?

nohup java -jar Server.jar &


Persistent white dot in Ubuntu Dock since 18.10 update

If the white dot bothers you, you can remove it by restarting GNOME shell.
To do this, press Alt+F2, then type r, and finally press Enter.


What options do you recommend for running an emulation of the Windows 7 operating system on Ubuntu?

VirtualBox often does a very good job - you can even get it to work with hardware accelaration:

You can also set up USB support.


Why are unexpected windows such as File Manager appearing on computer startup?

What you're experiencing is XFCE's automatic session saving. It will attempt to restore the session you had before logging out.

You can nuke the cached sessions with a quick rm -rf ~/.cache/sessions/* but for long-term disablement, there is another answer on the site that involves forcibly disabling it.

Chances are now that you know what to expect (if you leave windows open before you log out), you won't be so surprised and confused.


Try this: (because the microphone isn't stereo but mono)
Use Pulse Audio Volume Control (typing pavucontrol in the terminal) to unlock stereo sliders for the mic in 'Input Devices' tab. Drag the right slider down to zero.

source: http://ubuntuforums.org/showthread.php?p=10136037


Ubuntu 20.04.1 usb no longer functioning

Solved (at least enough). I edited /etc/default/grub to change the line GRUB_CMDLINE_LINUX="acpi=force irqpoll' (as I had previously attempted) and swapped the USB port for the mouse. One of the ports now functions, but not the other, so presumably I was testing the mouse in the still non-functioning port. I'm not sure why that wasn't functioning, but it's not mission-critical, so I'm closing this.


The imwheel is a GUI application that runs under X.  You don't have X running, nor an X DISPLAY available when the rc.local file is run.

You'll have an X DISPLAY after you log in.  So to have this automatically run you should set it up as one of your startup application.

You can get to your Startup Applications configuration by typing "Startup Applications" in the Ubuntu Launch button search field.

Just click Add, then for the three fields put:

A name for the entry (any that you choose)
The command (in this case) imwheel
A comment (optional - to remind you what it does)

Click Add to save the new startup application, then close the window.


How to automatically poweroff when no wifi after a certain time?

You could adapt my answer to this question ("How to rotate WiFi connections"), changing The Next Thing (my answer uses it to bring up a different WiFi connection) to do what you want.


Can't update and can't install any package - files list file for package 'libatk-adaptor' is missing final newline

Have you tried

sudo dpkg --configure -a

It can sometimes repair a broken database. Source How to repair apt-get command?


Can you open Ubuntu Server from Ubuntu Desktop?

"Just look for an app called terminal in the Ubuntu Desktop. Open that and you will see the "server" in a window."
– user68186 1 hour ago

"There's no server program that you cannot run in the Desktop. You can use your rpi using GUI and at the same time run whatever server program that you want. And if you want the text-based UI , you can login in another tty . By pressing for example Ctrl+Alt+Fx to go into the ttyX ( the default range is actually 1-7 )."
– Parsa Mousavi 1 hour ago

Just got these comments, and I am satisfied with them for answers.  Did not actually realize that running the terminal was actually running the server itself, and that it can still run all the same programs the even with the desktop installed.  Thank you to all who answered.


To start tor browser from terminal, to the path where you have downloaded and extracted tor(assuming it is in ~/) and then:

cd tor-browser_en-US

and to start tor:

./start-tor-browser

When this window pops up:

Click on Settings -> Network and add your Address, Port, Username and Password and if your ISP blocks connecting to tor network, you may need to add bridges to make it work. To add a bridge, please refer to this turorial.


"latex it!" button (add-on for Thunderbird) not accessible?

found out:

The first time, you have to compose a new message,
right click on the new message toolbar,
click on customize
and drag the latexit button (which is now visible) to the message toolbar.

It'll stay there afterwards,


Apple Magic Keyboard 2, not working properly over bluetooth (16.10)

Okay, answering my own question here, I seem to have found a way that works, consistently.

Everytime the bluetooth has problems connecting, do the following:

Remove the already paired device from bluetooth UI (select it, and click -, this step is definitely important)
Do the following in a terminal:

  bluetoothctl
  ->power off
  ->power on
  ->scan on // this should find the keyboard in seconds, if It didn't, turn the keyboard off and on again.

  ->trust MAC_ADDR
  ->pair MAC_ADDR
  ->connect MAC_ADDR

This procedure has worked consistently for me. You might be able to remove the devices also from the bluetoothctl's CMD (remove MAC_ADDR), but it didn't work for me once and I found removing from the UI more consistent.

Hope this helps someone.


Config import on network-manager-openvpn

Try connecting to VPN from command line. This will make sure that the problem is with NetworkManager and not something else. You can connect from command line using:

openvpn --config /path/to/config.ovpn

You may need to run this command using sudo.

If you can successfully connect from command line then try adding yourself to netdev group and uncheck Available to all users in vpn settings window in NetworkManager and then try connecting using NM.


How to enable IPV6 packet capturing in WireShark at the same time as IPV4?

By default, there is nothing that you need to do. Simply select the appropriate interface to capture on, and start capturing. All traffic on that interface will be captured.

To show only ipv6 traffic in the display, you simply enter ipv6 as the filter match.


Coloured view in vim editor not working in ubuntu 12.04

Try sudo apt-get install vim. By default Ubuntu comes with vim-minimal (which does not have syntax highlighting).


I was able to fix this after many, many hours. It was a combination of quite a few issues.
Issue #1: Deleting files using a Live USB
I had booted using a Live USB to try to delete files. In hindsight, it would have been better to just SSH in and manually rm -rf the files.
Because I booted with a Live USB to delete files, the files weren't fully deleted. Instead, they were moved to a file /.Trash-0. This is because:

Whenever you mount an external disk, a trash-* directory will be
created in the "root" directory where files are moved to if deleted
from the GUI, like the trash on your desktop.
This is to improve file recovery for external drives. (E.g. USB sticks
or HDDs)
Source

So to sum that up, when using a Live USB to delete files, the files will actually be moved into /.Trash-0 instead of actually being deleted.
Issue #2: trash-cli
Someone in the lab had added the alias:
alias rm = 'trash-put`

trash-put is a tool that moves files into a Trash folder from the command line. Unlike rm, which immediately and permanently removes a file, trash-put allows you to restore the files from the Trash folder.
When the tool was first released, it was recommended to make this change. However, the author now strongly recommendss not to make this alias source.
You can avoid using the alias rm if someone has set it by doing \rm instead of rm.
How I figured this out
I was trying to use lsof to find a file that was being held open by a process and not allowed to be deleted. However, this didn't help me because the file wasn't being held open. It was just sitting inside a different trash folder.
I was able to finally find where it was by doing:
# Switch to the admin account
$ sudo su administrator

# Move into the root directory
$ cd /

# List the top ten largest files
$ sudo du . | sort -nr | head -n10

I did this and the largest file was ./Trash-0 followed by ./.Trash-0/files.
I was able to delete the files by doing sudo \rm -rf ./.Trash-0 (for people without an aliased rm, you can just do sudo rm -rf ./.Trash-0).
Takeaways
Some lessons I learned from this experience:

Make backups
Don't use Kazam to make screen recordings
After working to solve a problem for 8 hours, you should probably come back to it fresh
Using a Live USB to delete files isn't the best move
Don't build a $300,000 research robot with only 128 GB of memory
To give yourself enough memory for basic functionality, you can use sudo tune2fs -m 0 /dev/sda6 to allow you to use memory preserved for essential functions. Make sure to restore this to sudo tune2fs -m 5 /dev/sda6 when you're done.


Ubuntu Phone BQ E5: File manager broken, Unable to install Dekko

For your file manager issue, have you tried uninstalling & reinstalling? To uninstall tap & hold the app icon, this will bring you to the relevant app page, with an uninstall button. I'd consider a reboot between uninstall & reinstall.

Hope this helps,

Jurjen


Copy all files from one folder to another in linux

Option 1

You can try the following trick and change your command to

cp sourceDir/*.* destDir

it will only copy files in the same folder, as long as they have the format like filename.ext. Make sure you have not folder with the same format.

Option 2

Otherwise you try the following command:

find /sourceDir/ -type f -execdir cp "{}" /destDir/ ";"

It will search for all files inside the sourceDir and then copies them to the destDir.


You need to modify the boot order in your bios/uefi settings. If you don't know how to enter the settings try holding down Esc, Del, or F2 while booting. In the settings you need to look for a boot devices or boot order section. Move the Ubuntu-Partition to the top and you should be good to go. You should still be able to boot to windows from the Grub.


If you are going to use sudo with graphical applications, such as nautilus, than you really ought to use gksudo. I don't have enough rep to comment, but this is important because it is a security risk to run graphical programs with normal sudo, so thought I'd mention that. A better approach would be to open a terminal and navigate to the mountpoint, probably somewhere like /media/$user/device , and than run ls -l to figure out the permissions.

Regarding the original question, what kind of file system is the external drive formatted to? You can find out by running as root fdisk -l I have had this problem before with a VFAT partition. Even when logged in as root I could not write to the partition. Sometimes this can be caused by corruption on the disc or partition, it's very frustrating.

I am still looking for an answer to the VFAT no write access issue myself.


IO_PAGE_FAULT when copying files between two HD

swap
Your /swapfile (swap_1) is too small. Hence the IO_PAGE_FAULTs.
Note: Incorrect use of the dd command can cause data loss. Suggest copy/paste.
In the terminal...
sudo swapoff -a           # turn off swap

Note: locate and delete your swap_1 file (it may not be in /, as your line in /etc/fstab is incorrect)...
#sudo rm -i /swapfile      # remove old /swapfile

sudo dd if=/dev/zero of=/swapfile bs=1M count=4096

sudo chmod 600 /swapfile  # set proper file protections
sudo mkswap /swapfile     # init /swapfile
sudo swapon /swapfile     # turn on swap
free -h                   # confirm 13G RAM and 4G swap

Confirm this /swapfile line at the end of /etc/fstab... and confirm no other “swap” lines...
Note: edit your existing swap_1 line in /etc/fstab to look like the following...
To edit, use sudo -H gedit /etc/fstab or sudo pico /etc/fstab
/swapfile  none  swap  sw  0  0

reboot                    # reboot and verify operation

memory
13G RAM is an odd amount. Please edit your question and show me:
sudo lshw -C memory
Go to https://www.memtest86.com/ and download/run their free memtest to test your memory. Get at least one complete pass of all the 4/4 tests to confirm good memory. This may take many hours to complete.
Update #1:
A BIOS update from version "50a" to "50e" resolved the problem.


It reported an I/O error on sda1 repeatedly.

Then it's not a filesystem issue, but a failing drive (or I/O controller). Run diagnostics on your drive (SMART reporting) from a live CD to verify this. Create backups a.s.a.p. (mount read-only and copy files somewhere else).


Known Chrome/Chromium themes that match popular themes

Chromium/Chrome is not perfect as far as gui integration goes but there are a few workarounds.

If you go to Preferences >> Personal, under Appearance you can select "Use GTK theme" and "Use system titlebar and borders".

Now, not always the system titlebar and borders will match chromium's ui (and you use extra space doing this) so I personally use it hidden. I stick to GTK for the icons and colors that match orta.

Equinox (Dawn) seems to have a little issue with the GTK theme as, while it does match and look nice, the icons are that of Faenza-Dark against a light background. You could change those specific icons in the /usr/share/icons/Faenza-dark folder. Not ideal but it works.

The other 3 Equinox gnome themes seem to work fine out of the box with this method.

There are extensions to achieve scrollbars that match your taste/you theme.

Elementary Scrollbar: https://chrome.google.com/webstore/detail/kglninkafjojambbaogionamfcelppil

Elementary Theme: https://chrome.google.com/webstore/detail/pdongokkdiclimbompodchjpdglpfemg )

Simple Bar (Orta-esque scroll):
https://chrome.google.com/webstore/detail/lagmbbmdlgjncefjognkcadapmmkmphe

Adwaita Scrollbar:
https://chrome.google.com/webstore/detail/bkgmaggeefkcgmhmgiadbhgdoeiajccd

There is also a theme for Divergence III (althought Divergence is already at IV).
https://chrome.google.com/webstore/detail/fejliiokfekdkmfjoeggpkdlndgbcopj

And for Shiki:
(White) https://chrome.google.com/webstore/detail/imbkdgihphehomdldnjomialcnehgnih

There are bound to be a few more similars one but my honest advice is to go with GTK if you can't find the specific theme for your setup. :)

Disclaimer: my ubuntu is in portuguese, forgive me if anything is incorrectly named - should be close enough.


Fixed the issue by creating USB using Startup Disk Creator


Can't start default file manager on Ubuntu 14.04

If you are currently using nautilus, Then try re-installing Nautilus file manager again !

First,try updating the Repositories. Use this code (In a terminal):

sudo apt-get update

and press enter. Then,

sudo apt-get install --reinstall nautilus

(In a terminal) and press enter

Hope this works !


Ubuntu 18.10 is stuck at loading screen after new installation

Looks like the OS is not able to take you to the login screen.

Try this:

Presst Ctrl+Alt+F2/F3/F4/F5/F6 this should take you to tty
Type: $ sudo chown -R $(whoami):$(whoami) ~/
Reboot
After running this command, you hopefully shouldn't have any problems logging in.

Also insure the integrity of your login manager. You can do this by installing lightdm with:

$ sudo apt install lightdm

At the command configuration prompt select Lightdm.

You can toggle between the Lightdm login manager and the Gnome login manager with this command:

$ sudo dpkg-reconfigure lightdm


Screen going black, further investigation reveals healthy ram and hard disk, and several kernel oops logs

If you beleve it is apyton error please tyr the following python version and PPA

sudo apt-get install python-software-properties
sudo add-apt-repository ppa:fkrull/deadsnakes
sudo apt-get update
sudo apt-get install python3.3
sudo apt-get upgrade

If this does not help please post the /var/crash logs you mentioned


Ctrl-Shift-U doesn't work on Ubuntu 15.10

I have found out a solution by myself: iBus wasn't working and I was closing it from the tray unknowingly. I have edited my .xinputrc to allow iBus to start. Still, I don't know why on the other accounts it worked normally; I will mention the contents of the edited .xinputrc below.

# im-config(8) generated on Sun, 07 Feb 2016 00:01:26 +0200
run_im ibus
XIM=none
XIM_PROGRAM=
XIM_ARGS=
GTK_IM_MODULE=gtk-im-module-simple
QT_IM_MODULE=xim
IMSETTINGS_IGNORE_ME=yes
DISABLE_IMSETTINGS=yes
# im-config signiture: cce1d9f2a380733e9faadc73e8c273ee  -


How can I get internet and Bluetooth working in Ubuntu 17.04?

There is a network manager file in 17.04 that blocked my system from automatically managing my devices, located here:

/usr/lib/NetworkManager/conf.d/10-globally-managed-devices.conf

Content:

[keyfile]

unmanaged-devices=*,except:type:wifi,except:type:wwan

I commented it all out, rebooted, and everything works fine now. It can also be deleted. Let me know if this helps.


Ubuntu 18.04 quit booting. . *ERROR* DC failed to blank crtcl (screen photo)

Holler;

The solution to your problem may lie in changing the following in your kernel boot line:

amdgpu.dc=0

You can find a detailed description of how to do this temporarily here:

https://wiki.ubuntu.com/Kernel/KernelBootParameters


Firefox Touchscreen in Ubuntu 20.04 with Wayland

I am unable to replicate this on Ubuntu 20.04, Gnome Session (Wayland), Firefox 77.0.1. I am however able to replicate it perfectly - the non-start, the terminal output - by logging in to the default Ubuntu session, which is still X-based.
The obvious question then is how sure you are that you really are on Wayland? Run the command echo $XDG_SESSION_TYPE from the command line. The response is wayland on the GNOME session (don't know if it works the Ubuntu on Wayland session).
You can install the "Gnome" session as the package gnome-session and select it from the settings pop menu in the lower right corner (assuming GDM), once you start typing in your password on the login screen. Or just try "Ubuntu on wayland" from the same menu.


Upgrade from 5.5.9-1ubuntu4.22 to PHP 5.6.0

to get the add-apt-repository command, you need to install software properties:

sudo apt-get install software-properties-common python-software-properties


How do I delete / rename files on Bq M10 file manager using attached keyboard/mouse?

In File Manager, go to the folder you want and then you will see a list of files. Hold down a finger (or a stylus !) on the file you want to delete for about a second. A menu appears with one of the options as 'Delete'.


Determine the output of uname -a. For example: 4.2.0-18-generic.
Then as you described above, use the LiveCD method to boot.

Download the following packages (replace 4.2.0-18-generic with your output above):

apt-get download linux-image-4.2.0-18-generic, linux-headers-4.2.0-18-generic, linux-image-extra-4.2.0-18-generic

Next copy these into your broken system's hard-drive. Reboot into your broken system and sudo dpkg -i all of these packages.


This is problem due to intel microcode issue. There are two solutions to this problem,

add a instruction dis_ucode_ldr in your grub file,
Update the BIOS. The updated BIOS seems to be working for my Dell Vostro.

You can see more details in a comprehensive forum post Ubuntu 18.04.2 boot stuck on purple screen after updates


Problem with video after upgrade to 14.04

Open up Software & Updates and navigate to the "additional drivers" tab. Select the proprietary Radeon driver from the list of drivers.


Follow up question to "Lenovo 18.04 No Wifi Adapter Found"

Courtesy of user @Jeremy31

Solution:

echo "blacklist ideapad-laptop" | sudo tee /etc/modprobe.d/ideapad-laptop.conf"

and then reboot.

Results:

rfkill list

0: phy0: Wireless LAN
      Soft blocked: no
      Hard blocked: no
1: hci0: Bluetooth
      Soft blocked: no
      Hard blocked: no

Also, wireless now works. Very simple solution not requiring web access. Yay.


Has upgraded to 16.04. b43 broadcom driver does not detect BCM4328 (PCI ID b4321) adapter. That works perfectly on 4.2 kernel

Just upgraded Ubuntu and everything works.


I assume you're using the NetworkManager GUI.  It seems that its default behaviour is to override the default route, even if the OpenVPN server isn't pushing it.

You can fix that behaviour by editing the VPN connection and on the IPv4 settings tab select the 'Routes...' button.
You'll see an option called 'Use this connection only for resources on this network'.  Make sure that's enabled and then restart your VPN.  That should sort you out.


All right, I found the solution:

It was all because I was using the Segoe UI Light font everywhere in the system, but Firefox was using Segoe UI Regular. By (hackishly) changing the font in About:Config, I managed to get it to look almost the way I wanted... but now, the font spacing is too low and things are squished together.

If anyone knows how to increase the spacing, that would be fantastic! :)


Press ALT and pull the window with your middle mouse click while holding both.


You can install any kernel you want. There is no problem on using one or multiple Kernels at a time. But sometime you should consider the Kernel Mapping to your Ubuntu Version. For example following link lists out the mapping of different kernel to different version of OS:

Ubuntu to Mainline kernel version mapping

You can get a complete information of Kernel installing/removing from following link.

Kernel Mainline Builds

It helped me a lot to install a new kernel in Ubuntu 12.04.2. Now I can chose any kernel 3.5.0 or 3.8.0 from grub menu.

Following link illustrates how Ubuntu 12.04 LTS works actually. It illustates in very nice way, you would also like:

Ubuntu LTS Enablement Stack

Hope this short description helps you.


Installing Ubuntu on laptop without a preinstalled OS?

Without an existing OS, the installation is easier - you have no need to worry about data retention or compatibility with prior operating systems.  I would be tempted to let Ubuntu do whatever it feels like to the disk (it will reformat and partition the disk by itself) unless you have a specific desire to have some partitions, like /home, seperated out.


Yakkety Yak MATE rc.local does not exist

One solution

A quick workaround (I don't know if that's the canonical way):

In a terminal do:

sudo touch /etc/rc.local
sudo chmod +x /etc/rc.local
sudo printf '#!/bin/bash\nexit 0' > /etc/rc.local
sudo reboot

After that the rc.local will be called upon system startup. Insert what you want.

Background

If you do in a terminal:

sudo systemctl edit --full rc-local

You can see that the head comment contains lines such as:

# This unit gets pulled automatically into multi-user.target by
# systemd-rc-local-generator if /etc/rc.local is executable.

This indicates, that in this system, if there is a file called /etc/rc.local which is executable, then it will be pulled into multi-user.target automatically. So you just create the according file (sudo touch...) an make it executable (sudo chmod +x ...).


Mount multiple shares with a single mount command

You can write a script which takes input for the username and password and applies it to each mount required. The script will need to be run with root level privileges. This also assumes that the mounts are all Samba shares. You'd need to tweak the script to include each of your mount points. With this script you will have to define all of your mount options rather than rely on those in fstab:

#!/bin/bash

echo "Enter username for mounts:"
read mount_user
[[ -z "mount_user" ]] && echo "Username empty, exiting" && exit

echo "Enter password for mounts:"
read -s mount_pass
[[ -z "mount_pass" ]] && echo "Password empty, exiting" && exit

# Mount first share
mount -t cifs //server1/share1 /mnt/share1 -o username="$mount_user",password="$mount_pass"
# Mount second share
mount ...

Save this script as something like /home/user/mountall, and execute it with sudo /home/user/mountall.

This does load your password into memory in plain, and into a variable in the script's running process. Whether that is considered insecure in your environment is a question for your security team.


You need to increase the maximum size of a chunk of shared memory Linux kernel allows to allocate at once (known as SHMMAX parameter)

You need to edit /etc/sysctl.conf and add the following line:

kernel.shmmax = 41943040

(where 41943040 is the size of memory in bytes, i.e. 40 megabytes. On production system you probably want to set this value way higher - Postgres documentation recommends to start with 1/4 of available memory)

Then run

sudo sysctl -p

and restart postgres again.

Alternatively, you can edit /etc/postgresql/<version>/main/postgresql.conf and reduce the value of shared_buffers parameter.

This is a bug, more info here

https://bugs.launchpad.net/ubuntu/+source/linux/+bug/264336

(there's also /etc/sysctl.d/30-postgresql-shm.conf file which is supposed to be used for this purpose but it doesn't seem to be included from the main config so editing it has no effect)


How to save and restore group of windows (not necessarily on reboot)

That's exactly how I run on a 16 GB machine using a combination of:

Workspaces
CompizConfig Settings Manager's Place windows plug-in which will allow an application that isn't running to open on its particular workspace at its pre-defined X-Y coordinate,
autostarting individual applications
For individual applications opening individual files it depends on the application itself:

Example for gedit
Example for  FireFox
etc...

Create multiple users on your machine so they each have their own sessions
Hibernation

The more users and applications, the more RAM usage, though...


Converting from 2D to 3D is impossible...
Why? Because of the entropy of the universe of course!  :-)
(Meaning: You cannot add what's not there; 3D movies are filmed with 2 cameras, one of each eye; 2D movies are filmed with 1 camera)¹
Converting from 2D to Side-by-Syde (SBS) 2D is possible however:
ffmpeg -i 2D.mp4 -filter_complex \
       "[0]scale=iw*sar:ih,setsar=1,scale=-1:$720,\
        crop=$720:$720,split[left][right]; \
        [left][right]hstack[sbs]" -map "[sbs]" -map 0:a? SBS.mp4

which will give you a movie that you can still watch using cardboard, but it'll be 2D, not 3D.
in the above command, you can change the following options:

720 to the resolution you want (SD=540, HD=720,FHD=1080, but any value can be taken)
2D.mp4 is the input file
SBS.mp4 is the output file

¹Yes, it's more complex than that, but let's keep it simple...  ;-)


Just installed Ubuntu 16.04 and trying to get drivers installed for wireless USB adaptor

The short answer is:

find out what chip is used in your adapter.
find the source code for a driver and compile it.
use modprobe to install the module into the kernel.
use dkms to allow the source code to be built when the kernel updates.

To that end:

open terminal and type lsusb

look for an entry that shows your D-Link, like such:

Bus 002 Device 010: ID 2001:3314 D-Link Corp.

the 2001:3314 is the vendor:device ID

Google 2001:3314

one of the results will take you here:
 https://wikidevi.com/wiki/D-Link_DWA-171_rev_A1
 look at the right side of the page and it'll identify a driver.
download the driver and compile it with "make".
if there are no compiler errors, use "modprobe" to load the kernel
module, and test your device now.
install "dkms" and learn how to make it so that the module will rebuild
automatically when Ubuntu updates the kernel software.


How can I display the list of available WiFi networks?

Use nmcli dev wifi command. It shows the transfer rate, the signal strength and the security as well.


switching between graphics cards and on board graphics in ubuntu

You can use AMD's proprietary driver to install the Catalyst Control Center, which lets you choose between the graphics card or the CPU's integrated graphics. I've read that, because Intel + AMD switching is fairly new, the automatic features may not work yet. However, the Control Center supposedly lets you switch manually in software.

AMD's website, which may be out of date, notes in the fine print,

  Linux OS supports manual switching which requires restart of X-Server to switch between graphics solutions.

Also have a look at this relevant Linux Mint forum thread about AMD graphics. Users there seem to have had some luck with automatic switching.


Usb keyboard and mouse recognized but not working in Ubuntu 12.04

It turned out I had the virtual kernel installed (I probably installed it while trying to fix VirtualBox). Grub was loading this kernel as the default kernel which broke the use of mouse and keyboard. Running the normal kernel fixed it. Maybe this helps someone with a similar setup.


How can I replace my windows partition with another Ubuntu based distro, in a dual boot system?

If you didn't care what was on the Windows partition (files, programs, etc) you could overwrite it by pointing the installer at that partition. If you still want the files on Windows, you would need to back those files up (or the enitire OS if you wanted) to external storage.


The EFI stub loader is a component of the kernel, not a separate program. When the EFI stub loader is included in the kernel, that kernel file looks like a normal EFI program to the EFI, but it's still a normal kernel that can be loaded by the usual Linux boot loaders -- GRUB, LILO, ELILO, SYSLINUX, etc. The EFI stub has been available since kernel 3.3.0, and AFAIK, all Ubuntu kernels built since then have included this feature.

There's no law that says that kernels with EFI stub loaders have to have filenames that end in .efi. In fact, the kernels installed to the hard disk lack the .efi filename extension; this seems to be unique to the kernel on the installation disc, at least in Ubuntu. The EFI shell won't run a program unless it has a .efi extension, though. Thus, giving the kernel that filename provides one means of recovery and testing for advanced users that might otherwise be unavailable to them -- namely, manually launching the kernel from an EFI shell. I can't be sure, but I suspect that the Ubuntu developers are now naming their kernels in this way to provide this backup means of launching the kernel, or perhaps just to signify that it does contain EFI stub support. OTOH, the 32-bit Ubuntu installation disc's kernel lacks the .efi extension, but it does include EFI stub support. My suspicion is that the Ubuntu developers just aren't naming their kernels consistently.

It's possible to launch an EFI application (such as a Linux kernel with EFI stub support) from any location on the disk. The "casper" subdirectory is not a location where boot loaders normally reside, but it is possible to launch EFI programs from there.

Whatever source you read that says the 64-bit kernel has a .efi extension because it's a 64-bit kernel is wrong. In practice, the 32-bit version of Ubuntu has a kernel that lacks this extension, so there is a correlation in the Ubuntu world, but there's no causation involved. In Linux generally, a .efi extension does not indicate a 64-bit kernel -- there are plenty of 64-bit kernels that lack this extension, and it may be desirable to name a 32-bit kernel with that extension on a 32-bit UEFI-based computer (although Ubuntu doesn't do so). That filename extension simply identifies an EFI application, which can be 32-bit (x86/IA-32), 64-bit (x86-64/AMD64), or some other architecture (ARM or Itanium).


Will Ubuntu degrade my macbook pro battery?

Ubuntu or should I say Linux doesn't degrade batteries, it just puts to use what is already there and uses enough power to run the kernel and software the end-user needs to run...  Power management is always being worked on to make things run better for longer and of course choosing a lighter desktop like XFCE or LXDE will make the battery go farther than eye-candy rich desktops like Unity and KDE...


Install adb & fastboot via PPA

You can install from the WebUpd8 PPA which support both 32-bit and 64-bit. Granted you can install directly from google. But I prefer to use PPAs to keep everything up to date.
Works for Ubuntu 11.04, 11.10 and 12.04.

sudo add-apt-repository ppa:nilarimogard/webupd8
sudo apt-get update
sudo apt-get install android-tools-adb android-tools-fastboot

Source: Install ADB And Fastboot Android Tools In Ubuntu Via PPA

Install Android SDK via PPA

If you want to install the SDK which will allow you to update everything you can install via the upubuntu ppa.

So first thing is to add the ppa.

sudo add-apt-repository ppa:upubuntu-com/sdk
sudo apt-get update
sudo apt-get install android-sdk

Only issue at this point is that android-sdk needs to be run as root. Well the link in the menu didn't do much. So I updated the link in the menu, you can also run:

gksu android-sdk

From there you will need to install "Android SDK Platform-Tools" I also recommend updating "Android SDK Tools". You can deselect anything else you don't need.

Now you will need to set your environmental variables.
First you will need to make everything executable.

sudo chmod -R 755 /root/android-sdk-linux

Now to add the variables.

nano ~/.bashrc

Add these lines (at the top)

#AndroidDev PATH
export PATH=${PATH}:/root/android-sdk-linux/tools
export PATH=${PATH}:/root/android-sdk-linux/platform-tools

Source: Install Android SDK Manager (Revision 20) From PPA On Ubuntu 12.04/Linux Mint 13

Source: AndroidSDK - Community Ubuntu Documentation


Ubuntu 11.10 includes GNOME 3 GTK+3 libraries with the updated Unity user interface.

If you want, you can install GNOME Shell using these directions:

How do I install and use the latest version of GNOME?


Unable to connect to xmpp account with Thunderbird

The link shared by unor helped me to fix this issue.

The IM account was unable to connect due to certificate issue. Though I had a valid certificate the app wasn't able to verify the certificate.

Here is the detailed steps on how to fix the issue.

Get the proper certificates

Get the certificate (If you don't have one) from pidgin account.

open Tools -> Certificates
select the appropriate hostname and click "Save" (file: certificate.pem)

Open Thunderbird -> Edit -> Preference -> Advanced

choose Certificates tab -> View Certificates
Select Servers and Click Import to add the download "Certificate.pem" and save it.

or

Use this link https://kingant.net/check_xmpp_dns/ to get proper server details.

open the link and enter "yourdomain.com" to fetch the server details

Copy the Target value in "Client records for yourdomain.com". In this case, it is c2s.webex.com.webexconnect.com

Open Thunderbird -> Edit -> Preference -> Advanced

choose Certificates tab -> View Certificates
Select Servers
Click on "Add Exception..."
Enter the copied text under "Server Location:" with :5222 at the end (Replace https:// with  c2s.webex.com.webexconnect.com:5222)
Click on "Get Certificate" and remember to tick "Permanently Store this exception" and save the setting by clicking on "Confirm Security Exception"

Adding XMPP account

Open Thunderbird -> Edit -> Account Settings
Add Chat Account

select xmpp
username: name@domain.com
password: .......
Resource: Doesn't really matter
Server: im.domain.com or the text grabbed from the URL(c2s.webex.com.webexconnect.com)
Port : 5222

Now we are good to go :)


Video Training Courses for Linux/Ubuntu?

You may lose focus if you don't download the video tutorials so that you can watch them locally. YouTube has some good Ubuntu tutorial channels, this channel for example. What sets the videos in this channel apart from other YouTube tutorial videos, is that while the videos are not interactive, in order to get the full benefit of the videos you should try out the code and even change it in order to get your own customized output.

If you install the youtube-dl application from the Ubuntu Software Center you can batch download an entire series of video tutorials from YouTube with a single command in the terminal, and using the -c flag the download can be resumed in the same place it was stopped if it is paused or interrupted. Youtube-dl also lets you choose the format of the video that you want to download. I recommend selecting the 480p mp4 format if it is available. Less than 480p makes it difficult to read the text on the screen, and YouTube videos usually look OK in 480p.


How to minimize Ubuntu 16.04 bloated installation

Install as normal then purge what you do not need. For example, the first thing I do on every Ubuntu installation is sudo apt-get -y purge evolution-data-server followed by sudo apt-get -y --purge autoremove. This gives me about 200 MiB more free memory...

The other variant is to go bottom up. Install Ubuntu Server, then

sudo apt-get install --no-install-recommends ubuntu-desktop

To see what is missing from the full desktop installation use

apt-cache show ubuntu-desktop | grep "Recommends"


Finally solved this (hope the op is still checking this)  Make sure your bios is current, double check that safe boot is OFF (you have to delete settings to do this, there are guides for it)  and specific to the Asus G111cd mb....   turn off the pci energy management in bios as well as disable the non proprietary driver in the install config.    it's wierd, but totally solved all of my install problems.  once installed, immediately update the nvidia driver to their proprietary one, and then done.  gl !


How can I invert my display colours under Kubuntu?

Open SystemSettings (from the K > Computer menu). Go to Desktop Effects then in the All Effects tab you'll see the top item in accessibility is "invert". It should be easy enough, tick the checkbox, set your preferred hotkeys and voila.


After adding:

deb http://ubuntu.mirror.cambrium.nl/ubuntu/ raring main universe

from

http://packages.ubuntu.com/us/raring/i386/python-lzma/download

it worked for me.

Hope it helps you, too.


You can get to some recovery options by selecting Advanced Options for Ubuntu in the GRUB menu.

Just reboot your computer, and when you get to the GRUB menu, select the Advanced Options for Ubuntu using your arrow keys. You should see one option for recovery mode.


You can upgrade the kernel in Ubuntu 14.04 by running in terminal:

sudo apt-get install linux-generic-lts-wily

Test the touchpad after reboot.


Install Ubuntu splitted in two devices i.e. HDD and SD card

Well, the Ubuntu Desktop System requirements say that you need 5GB of disk space. But they also mention that hard drive memory issues can be resolved by using a Live System. If you want to do that you might want to try a Persistent Live USB installation. But here's the catch: Such a system uses a lot of RAM. So, checking your RAM capacities is probably a good idea.


You can always have the database residing on a directory on the SSH server and mount locally on a client that directory through sshfs.


How can I setup NoMachines on my Linux Vps

To install a gui on your server, you're best following this guide: https://help.ubuntu.com/community/ServerGUI. That will get a GUI on your system.

The next step is to get remote desktop software. NoMachines looks like a proprietary implementation of NX technology (http://en.wikipedia.org/wiki/NX_technology). There is an open source implementationm called FreeNX which works on Ubuntu and the Wiki has a tutorial for setting it up: https://help.ubuntu.com/community/FreeNX. There is also a free implementation created by Google, but it seems less feature complete at the moment.

There are also a couple of other Remote Desktop protocols that you could have a look at such as VNC. I've used it in the past for this style of thing and it's worked well. There's more info about it on the Wiki (search it for VNC, I can only post 2 links per comment here).


Confgiuring Ubuntu 20.04 with LightDM - How to enable lock screen

It looks like there is a security issue related to locking using LightDM
See: https://bugs.launchpad.net/ubuntu/+source/lightdm/+bug/1806961
One option is to switch to gdm3:
sudo dpkg-reconfigure gdm3


Cannot detect second display - Ubuntu 17.04*

I have met the same issue.
one day, cuda went wrong and told me that can not communicate with nvidia driver.
after I reinstall the nvidia driver.
the system cannot detect the 2nd monitor.
and I solved the issue by removing the following line：

  Option "IgnoreDisplayDevices" "CRT"

in /etc/X11/xorg.conf

hope this will be helpful.


I actually dont find the solution to the problem but instead of installing Overwatch from lutris i installed battlenet from lutris and install overwatch from there

https://lutris.net/games/battlenet/

The gold DOX version worked like a charm its capable of running all blizard games and has configured DXVK already so no settings needed just some dependecies.Vulkan expirience out of the box.


Way to make ISO date-time format universal throughout Ubuntu?

The simple answer is: no. I.e. not without changing all programs which don't pay regard to the selected locale for date and time formatting.


Getting "You do not have permission to copy this file" while importing files from Android

As I thought, a problem due to MTP.
I tried these commands;

sudo apt-get install golang fuse git-core libmtp-dev
sudo adduser $USER fuse mkdir /tmp/go
GOPATH=/tmp/go go get github.com/hanwen/go-mtpfs
sudo mv /tmp/go/bin/go-mtpfs /usr/bin
mkdir ~/MyAndrid

That installed "go-mtpfs".
Now to mount your android,

go-mtpfs ~/MyAndroid &

volia! Now you can find your contents at MyAndroid folder in your home directory. If you want to unmount your phone, type

fusermount -u ~/MyAndroid

That's it.


I've created custom xorg.conf for Nvidia card for avoiding tearing (see below). As you can see main line there is:

 Option         "metamodes" "nvidia-auto-select +0+0 { ForceFullCompositionPipeline = On }"

In case of failure try to generate own xorg.conf. Each update of Nvidia's drivers can replace your xorg.conf, thats why just replace it again.

This hack also fixed tearing in web-videos.

# nvidia-xconfig: X configuration file generated by nvidia-xconfig
# nvidia-xconfig:  version 364.19  (buildmeister@swio-display-x64-rhel04-11)  Tue Apr 19 15:22:17 PDT 2016

Section "ServerLayout"
    Identifier     "Layout0"
    Screen      0  "Screen0"
    InputDevice    "Keyboard0" "CoreKeyboard"
    InputDevice    "Mouse0" "CorePointer"
EndSection

Section "Files"
EndSection

Section "InputDevice"
    # generated from default
    Identifier     "Mouse0"
    Driver         "mouse"
    Option         "Protocol" "auto"
    Option         "Device" "/dev/psaux"
    Option         "Emulate3Buttons" "no"
    Option         "ZAxisMapping" "4 5"
EndSection

Section "InputDevice"
    # generated from default
    Identifier     "Keyboard0"
    Driver         "kbd"
EndSection

Section "Monitor"
    Identifier     "Monitor0"
    VendorName     "Unknown"
    ModelName      "Unknown"
    HorizSync       28.0 - 33.0
    VertRefresh     43.0 - 72.0
    Option         "DPMS"
EndSection

Section "Device"
    Identifier     "Device0"
    Driver         "nvidia"
    VendorName     "NVIDIA Corporation"
EndSection

Section "Screen"
    Identifier     "Screen0"
    Device         "Device0"
    Monitor        "Monitor0"
    Option         "metamodes" "nvidia-auto-select +0+0 { ForceFullCompositionPipeline = On }"
    DefaultDepth    24
    SubSection     "Display"
        Depth       24
    EndSubSection
EndSection


According to Apache documentation, ServerName requires an FQDN. localhost name is not a Fully qualified domain name.

I suggest to change your vhost configuration:

      <VirtualHost *:80>
          DocumentRoot /opt/lampp/htdocs
          ServerName firstSite.localhost
          ServerAlias www.firstSite.localhost
      </VirtualHost>

      <VirtualHost *:80>
          DocumentRoot /home/mirjalal/localhost2
          ServerName secondSite.localhost
          ServerAlias www.secondSite.localhost
          <Directory "/home/mirjalal/localhost2">
                 Options +Indexes FollowSymLinks
                 AllowOverride All
                 Require all granted
          </Directory>
      </VirtualHost>

Where VirtualHost *:80 means that apache listen on any IP address, port 80 and that you are defining "Name-based virtual hosts".
ServerName now are FQDN consists of two parts: the hostname and the domain name.
DocumentRoot sets the directory from which httpd will serve files.

I add Directory directive because I guess main server (defined in apache2.conf) doesn't do that for your /home/mirjalal/localhost2 directory.

Save this directive in /etc/apache2/sites-available/myWebSite.conf

Open your /etc/hosts and change hostname:

      127.0.0.1 localhost
      127.0.1.1 mirjalal-PC
      127.0.0.1 firstSite.localhost
      127.0.0.1 secondSite.localhost

Now we are ready to start new site and stop default vhosts listen on localhost:

      a2ensite myWebSite
      a2dissite 000-default
      service apache2 reload

In order to verify put a simple file index.html in /home/mirjalal/localhost2 and try http://secondSite.localhost/


Grub shell greets me at boot-up, instead of a menu

ASsuming you want Ubuntu to run the boot with grub

Get into the system as you have been doing, open a terminal and run thse two commands

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

You could try bootrepair tool

https://help.ubuntu.com/community/Boot-Repair

Grub2 wiki is here https://help.ubuntu.com/community/Grub2 but as you have said it's not as simple to deal with as grub legacy was.


I need to access files and printer on a Windows machine on my home network from Ubuntu 18.04

You can enter the IP adress in the adress bar: smb://IP/ an then you should have acess to your Shared Folders from Windows.

You can jump to the adress bar with ctrl +L

For example the adress could be smb://192.168.0.42


Ripping DVD movie to near lossless video and audio quality

If applicable, decrypt the dvd.

Then concatenate the .vob files that make up the part of the dvd you wish to convert (they will be split into 1gb files for compatibility)

cat VTS_xx_xx.VOB VTS_xx_xx.VOB ... > intermediate.VOB

Then, use ffmpeg to convert the file to mkv with no loss of quality

ffmpeg -i intermediate.VOB -q 0 output.mkv

That's it. You're done.


Ubuntu New Install. Did it wipe my HD ? (I hope so)

Did the new install completely wipe my HD?

No, it did not.
It only just reformatted and repartitioned the drive to remove references to the windows files and make room for Ubuntu and its ext4 filesystem.
There are easy to use tools to recover most of your files and documents from the previous installation (see e.g. this question).
In case you had sensible data on the drive that you don't want to be recovered you will need to completely overwrite all sectors of the drive. This was not done by an installation of Ubuntu. See this question on securely removing data.


How can I write a dynamically updated panel app / indicator?

Since what seems to be the occasion to ask this question already has an answer, I am answering this question as an extended explanation on how it was done (in python)
Basic static indicator
Since Ubuntu Mate, from 15,10, supports indicators, there is not much difference between writing an indicator and a panel app for Mate. Therefore, this link is a good starting point for a basic indicator in python, using the AppIndicator3 API. The link is a nice start, but does not provide any information on how to show text on the indicator, let alone how to update the text (or icon). Nevertheless, with a few additions, this leads to a basic "frame" of an indicator as below. It will show an icon, a text label and a menu:

#!/usr/bin/env python3
import signal
import gi
gi.require_version('Gtk', '3.0')
gi.require_version('AppIndicator3', '0.1')
from gi.repository import Gtk, AppIndicator3

class Indicator():
    def __init__(self):
        self.app = 'test123'
        iconpath = "/opt/abouttime/icon/indicator_icon.png"
        self.indicator = AppIndicator3.Indicator.new(
            self.app, iconpath,
            AppIndicator3.IndicatorCategory.OTHER)
        self.indicator.set_status(AppIndicator3.IndicatorStatus.ACTIVE)
        self.indicator.set_menu(self.create_menu())
        self.indicator.set_label("1 Monkey", self.app)

    def create_menu(self):
        menu = Gtk.Menu()
        # menu item 1
        item_1 = Gtk.MenuItem('Menu item')
        # item_about.connect('activate', self.about)
        menu.append(item_1)
        # separator
        menu_sep = Gtk.SeparatorMenuItem()
        menu.append(menu_sep)
        # quit
        item_quit = Gtk.MenuItem('Quit')
        item_quit.connect('activate', self.stop)
        menu.append(item_quit)

        menu.show_all()
        return menu

    def stop(self, source):
        Gtk.main_quit()

Indicator()
signal.signal(signal.SIGINT, signal.SIG_DFL)
Gtk.main()

In the line AppIndicator3.IndicatorCategory.OTHER, the category is defined, as explaned in this (partially outdated) link. Setting the right category is important, a.o. to put the indicator in an appropriate position in the panel.
The main challenge; how to update the indicator text and/or icon
The real challenge is not how to write a basic indicator, but how to periodically update the text and/or icon of your indicator, since you want to have it show the (textual) time. To make the indicator work properly, we cannot simply use threading to start a second process to periodically update the interface. Well, actually we can, but on a longer run, it will lead to conflicts, as I found out.
Here is where GObject comes in, to, as it is put in this (also outdated) link:
call gobject.threads_init() at applicaiton initialization. Then you launch your threads normally, but make sure the threads never do any GUI tasks directly. Instead, you use gobject.idle_add to schedule GUI task to executed in the main thread
When we replace gobject.threads_init()  by GObject.threads_init() and gobject.idle_add by GObject.idle_add(), we pretty much have the updated version of how to run threads in a Gtk application. A simplified example, showing an increasing number of Monkeys:

#!/usr/bin/env python3
import signal
import gi
gi.require_version('Gtk', '3.0')
gi.require_version('AppIndicator3', '0.1')
from gi.repository import Gtk, AppIndicator3, GObject
import time
from threading import Thread

class Indicator():
    def __init__(self):
        self.app = 'test123'
        iconpath = "/opt/abouttime/icon/indicator_icon.png"
        self.indicator = AppIndicator3.Indicator.new(
            self.app, iconpath,
            AppIndicator3.IndicatorCategory.OTHER)
        self.indicator.set_status(AppIndicator3.IndicatorStatus.ACTIVE)
        self.indicator.set_menu(self.create_menu())
        self.indicator.set_label("1 Monkey", self.app)
        # the thread:
        self.update = Thread(target=self.show_seconds)
        # daemonize the thread to make the indicator stopable
        self.update.setDaemon(True)
        self.update.start()

    def create_menu(self):
        menu = Gtk.Menu()
        # menu item 1
        item_1 = Gtk.MenuItem('Menu item')
        # item_about.connect('activate', self.about)
        menu.append(item_1)
        # separator
        menu_sep = Gtk.SeparatorMenuItem()
        menu.append(menu_sep)
        # quit
        item_quit = Gtk.MenuItem('Quit')
        item_quit.connect('activate', self.stop)
        menu.append(item_quit)

        menu.show_all()
        return menu

    def show_seconds(self):
        t = 2
        while True:
            time.sleep(1)
            mention = str(t)+" Monkeys"
            # apply the interface update using  GObject.idle_add()
            GObject.idle_add(
                self.indicator.set_label,
                mention, self.app,
                priority=GObject.PRIORITY_DEFAULT
                )
            t += 1

    def stop(self, source):
        Gtk.main_quit()

Indicator()
# this is where we call GObject.threads_init()
GObject.threads_init()
signal.signal(signal.SIGINT, signal.SIG_DFL)
Gtk.main()

That's the principle. In the actual indicator in this answer, both the loop time and the indicator text were determined by a secondary module, imported in the script, but the main idea is the same.


Are 64-bit and 32-bit versions included in the same ISO?

No, they are separate images.  You should select the version that you want from the download page.  On the page you linked to, amd64 denotes the iso for 64bit, and those with i386 are 32 bit iso files.

You should also get the md5sum for the iso that you download and check that is correct before burning the image to a CD/DVD or USB stick.

If you have an unreliable internet connection then you might want to get the files from one of the official BitTorrent downloads because it will have extra error checking and the ability to recover and restart.


Windows doesn't recognize external hard-drive after installing Ubuntu (on internal hard-drive)

It may be because of the partition format. Windows works better on nfts format. Check your external hard drive and I suggest you  try to formatting it again in nfts (it will erase all the data on it)


You have a mix of GTK+ 2 and 3 applications; these use different theme engines. Install ubuntu-tweak to reset the GTK3 theme to its GTK2 counterpart. (xfce4 is still GTK2 and hence agnostic of GTK3)

If ubuntu tweak is too heavy, you can also manually edit /etc/gtk-3.0/settings.ini
Mine looks as follows:

[Settings]
gtk-theme-name = elementary
gtk-icon-theme-name = elementary-xfce
gtk-fallback-icon-theme = gnome
gtk-sound-theme-name = ubuntu
gtk-icon-sizes = panel-menu-bar=24,24
gtk-font-name = Droid Sans 9

Also, if you don't want to change the default gtk3 theme for all users, edit:

~/.config/gtk-3.0/settings.ini


I'm not part of Canonical, so I can't say what the plan is, but currently, mako, flo and hammerhead don't support rtc alarm (plus, hammerhead's RTC is kinda broken/rendered broken by other broken things). There are however some fixes in CyanogenMod's kernel for mako and flo which seem to fix it[1], so it is probably possible to make it work.

[1] for example this commit: https://github.com/CyanogenMod/android_kernel_google_msm/commit/c1429d6f7a8dc54f222aea14d63974cfca3d8df8


At the moment i found this solution.  First op all i reset compiz with :

gconftool-2 --recursive-unset /apps/compiz-1

and unity reset to:

unity --reset

I found this at www.webupd8.org.  The windows are normal now.  Compiz is my windows manager.  The colour is back and i can move the windows.


RocketRAID 640 - Ubuntu 16.04 / Kernel 4.13 Support

You have to dig, but there are some updated versions of the driver source. I was running rr64xl-linux-src-v1.3.11 that ran with Ubuntu 16.04. To add Kernel 4.13 support I had to patch several files. Here are some links that might help:

Seems to be some unofficial patched driver source
Discussion where I learned about applying the required patch to my 1.3.11 source. Perhaps the above driver source already includes these?

I don't use the RAID capabilities of this card. I simply wanted to add 4 SATA large capacity drives. I have 8TB and 4TB drives for my movies. The drives do occasionally go off line, but not to the point that I need to throw it away.


I've failed to install the R package, broken packages

I was getting a similar message when trying to install 3.5.2 over 3.4.4.
I had to

sudo nano /etc/apt/sources.list`
Then added a # to the line
deb https://cloud.r-project.org/bin/linux/ubuntu xenial-cran35/

Then I added a new line
`

deb https://cloud.r-project.org/bin/linux/ubuntu bionic-cran35/

Then I saved that and ran the following

sudo apt-get clean
sudo apt-get update
sudo apt-get install r-base r-recommended r-cran-*

That seems to have fixed one of the issues I was having but I am still having an issue install libxml2-dev in R.


Why not sync folders outside home with Ubuntu One?

It's not going to change, at least in the foreseeable future (and on this I can foresee a couple of years into the future). Allowing users to select arbitrary folders outside of their home for syncing with Ubuntu One, which could potentially sync between multiple different computers, opens a large number of usability problems to cover a use case that, quite frankly, isn't all that common.

One of the problems that I remember off the top of my head is that if you try to sync a mount point of a removable device (and quite a few people try to do this), when you remove the device syncdaemon will delete everything; to make it work properly syncdaemon would have to know about devices, detect their removal, things like that. Quite a large effort, and a lot of potential for usability nightmares.

Another problem is if you try to sync a folder with special permissions, ownership or file types in it: think of /etc/, /tmp/ or /dev/ as some of the worst cases. Or any folder you don't own, really. We could simply disallow syncing folders you don't own, but we know for a fact some people are running syncdaemon as root (despite our warnings).

A workaround for you would be to mount (via /etc/fstab, so you're reasonably sure the partition is mounted every time -- otherwise you risk losing your synced data) the /data folder into your home. You could simply move /data to ~/data or, if you have things that have the /data path hardcoded (quite likely), or if you're already used to /data yourself (also quite likely), symlink or bind mount /data to the mount point in your home. If you don't want to see it in your home at all, just make it ~/.data.


llvm-toolchain-8 is the source package, i.e. only the source code that is used to build all these respective tools. One source package can correspond to one or more binary packages with possibly different names.

When you scroll further down on the Launchpad source package page you linked, there's a section Binary packages built by this source, which is what you want instead - the already compiled and ready to use software packages. You see links down there to packages like e.g. clang-8.

Those binary packages are available from the Ubuntu repositories and can simply be installed like:

sudo apt install clang-8

However, clang-8 is currently only packaged for Ubuntu 19.04 and higher. On 18.10 you can use clang-7 and on 18.04 clang-6.0 only.

Or more simply, just install the clang package which pulls in the default version for your Ubuntu release, without you having to care for the exact number.


Access Ubuntu SSH Server from Ubuntu Desktop

ssh (package openssh-client) is a standard part of Ubuntu.

You may need to convert your private key from putty format for use with Linux ssh.

See: How do I install a ssh private key generated by puttygen?


install odoo 12 on ubuntu 18.04 - module not founderror : no module named 'babel'

Try this and see if it solves your particular issue with Babel:

sudo -H pip3 install babel


How to make username in terminal smaller?

You need to alter PS1 variable in your environment. PS1 is responsible of how fancy your command prompt will look alike, and what information it will contain.

Permanent change

Following is the excerpt of default .bashrc file in Ubuntu 10.04 LTS:

if [ "$color_prompt" = yes ]; then
    PS1='${debian_chroot:+($debian_chroot)}\[\033[01;32m\]\u@\h\[\033[00m\]:\[\033[01;34m\]\w\[\033[00m\]\$ '
else
    PS1='${debian_chroot:+($debian_chroot)}\u@\h:\w\$ '
fi

This makes command prompt look like this: username@hostname:~/directory$

If you change this and delete @\h part in PS1, you will get rid of hostname part in your command prompt:

if [ "$color_prompt" = yes ]; then
    PS1='${debian_chroot:+($debian_chroot)}\[\033[01;32m\]\u\[\033[00m\]:\[\033[01;34m\]\w\[\033[00m\]\$ '
else
    PS1='${debian_chroot:+($debian_chroot)}\u:\w\$ '
fi

Result: username:~/directory$

Temporary change

Override PS1 in your current bash session:

export PS1="\u:\w\$ "

Resources:

man bash
How to: Change / Setup bash custom prompt (PS1)
Color Bash Prompt


The command you typed

nc -lk 9999 | tail -f my_file.txt

means: Take the output of netcat and pipe that to tail -f my_file.txt. But tail doesn't accept any input, it merely watches the file my_file.txt. Try

tail -f my_file.txt | nc -lk 9999

instead, so that the output of tail is fed to nc.


how to check if Xen support hardware virtualization?

You are using an old command on a newer system. Please don't use instruction for a server 14.04 when you use 18.04.

xl is the default toolstack and as the error shows you need to us

xl

and not xm.

Not entirly true:  better is to check what

/etc/default/xen

is set to. It probably is xl.


How to install adobe flash into bootable USB

My understanding is that when creating a USB drive with Ubuntu's Live USB Creator application, it is possible to reserve some space to store data and packages installed "on top" of the ISO image. I.e. chances are all you need to do is actually install flash while booted from your USB drive.

See Ubuntu wiki for details.

In case your USB drive was created without this option (i.e. something like "discard changes on shutdown" has been chosen) - I'm afraid the easiest would be to re-create the drive, because it's basically an ISO filesystem (i.e. a CD image) and it's not supposed to be written to once created.


Run these first (in case g++ is not updated)

sudo apt-get update
sudo apt-get install g++

Then,

Start Code::Blocks.
Select Settings -> Compiler -> Toolchain-executable.
Select the […] button. Navigate to /usr/bin. The C compiler should be gcc, the C++ compiler should be g++ and the Linker for dynamic libs should be g++.
Select OK to close the dialog box.

This worked for me. Hope this helps.


How to find the site that crashes the server?

I don't known lot about your server configuration but I will try to help.

First start iptables and do not allow to attack your server

iptables -A INPUT -p tcp --dport 80 -m limit --limit 25/minute --limit-burst 100 -j ACCEPT

After that i think that logrotate can help us to find site with highest impact.

Install logrotate

sudo apt-get install logrotate

To verify that logrotate was successfully installed, run this in the command prompt.

logrotate

Configurations and default options for the logrotate utility are present in:

/etc/logrotate.conf

Some of the important configuration settings are : rotation-interval, log-file-size, rotation-count and compression.

Application-specific log file information (to override the defaults) are kept at:

/etc/logrotate.d/

My idea is to monitor http access file. Site with more access must have bigger access log. Logrotate and cron will watch for us on this and send you mail about problem ...

Edit logrotate.conf and add some code

sudo nano /etc/logrotate.conf

/path_to_apache_logs/*.log {
    size 1M
    dateext
    postrotate
      /usr/bin/killall -HUP httpd
      ls -ltr /path_to_apache_logs/ | mail -s "$HOSTNAME: Apache restarted and log files rotated" name@domain.com
    endscript
}

You must customise

size - size of log file, change based on your needs
path_to_apache_logs - change path based on log path in vhost.conf

More about customization of logrotate.conf you can find here

Setup cron to run logrotate on every 5 min

*/5  *  *  *  *   root    /usr/sbin/logrotate /etc/logrotate.conf

When you are on "attack" you access log will growth fast. Cron will run logrotate to check log file size and if file size is XX will rotate log, restart atache and send you mail.

Because every virtual host have own access file you will known witch site is server "killer"


apt-get ignores all packages with "Translation-en_US"

That means that the update process had checked that particulary repository list, and yours is up-to-date, so, for this is ignored.  Moreover, the ignored repository lists are not the same at every update.

If you want to pass over these ignored packages and speed up your update, follow this answer.


Audacious player doesn't play a list of audio files, when I mark and open several files in the file manager, since the update from 16.04 to 18.04

IMO the problem is with the developers of Audacious. They may say that this is not their problem, and rather a Nautilus problem, but they are the developers. So adapt! ;)

For those who do not want to wait, here is a working solution for Ubuntu 19.04. Create a script /home/myuser/.config/audacious/start-audacious.sh with the following contents:

#!/bin/bash

echo "$1" >> ~/.config/audacious/playlist.m3u

# Check if another instance of this script is running.
pidof -o %PPID -x $0 >/dev/null && echo "ERROR: Script $0 already running" && exit 1

sleep 0.1
audacious ~/.config/audacious/playlist.m3u
rm ~/.config/audacious/playlist.m3u

Then allow execution of this file:

chmod +x /home/myuser/.config/audacious/start-audacious.sh

Then edit the file /usr/share/applications/audacious.desktop and replace Exec=audacious %U with Exec=/home/myuser/.config/audacious/start-audacious.sh.

That's it. No restart needed for any service. Now go take Nautilus to your *.mp3 files, mark a couple, and press Enter. Audacious should open your selection.

P.S.: Replace myuser by your user! ;)


mapping values are not allowed in this context

The issue is the indentation used within the .yaml file

In your example there is a two whitespace inndentation after 'network:' before 'version: 2' but after 'wifis:' and subsequently only one additional space is used as an indent.  you can use either/or but not both, so the following will work:

# Let NetworkManager manage all devices on this system
network:
  version: 2
  renderer: NetworkManager
  wifis:
    wlan0:
      dhcp4:no
      dhcp6:no
      addresses: [10.10.10.1/24]
      gateway4: 10.10.10.254

You MUST keep the indentations uniform


First step is to immediately turn off suspend when inactive option in 'system settings'. Then later with no files open experiment with Suspend/Resume feature analyzing error logs like /var/log/syslog. Sorry I can't type real answer from my phone.
. Just this short commentary.


Can I convert my KDE Neon system to regular Ubuntu Bionic without reinstalling?

No, you cannot.

A release-upgrade is NOT like a clean-install.

Release-upgrades simply update your Ubuntu sources, and then pull updated packages from the new repositories. If you have version conflicts, file conflicts, held broken packages, or other common apt problems, a release-upgrade rarely fixes the problem. Indeed, it often makes the problem worse.

If your system can do a sudo apt update and sudo apt upgrade without any errors, and your system has no software from non-Ubuntu sources, then a release-upgrade is a fast, convenient way to migrate your system to the next release of Ubuntu.

If you wish to fix your system, then the usual method is to methodically uninstall all software from each non-Ubuntu repository until the error messages cease. One PPA or non-Ubuntu repository at a time. Several apt commands (policy, 'depends', and 'rdepends') are very helpful tracing the dependencies and versions. Software in the Ubuntu repositories is versioned and tested to prevent those common apt errors, and usually does not need to be removed.

If time is short, or fixing looks too difficult then backup your data and do a clean install.