Full Disk Encryption using Ubuntu Core\Snappy

I did ask this question yesterday in the snappy channel of the Ubuntu Rocket chat server and zyga told me this:

It is not supported, you can experiment and tweak but you get to keep all the pieces if it breaks; unattended encryption requires a few pieces to align and they are not available yet
on hardware like pi3 I think it is not sensible (no TPM)

I then told him about the possibility of using a solution similar to this one:

https://www.offensive-security.com/kali-linux/raspberry-pi-luks-disk-encryption/

but he told me that:

then you reboot overnight and it's annoying IMHO that's not the right hardware for the task
snappy will automatically reboot your hardware on update.

So the only option that I can think of is:

Use the "regular" Ubuntu Server image.
Do a Full Disk Encryption following this methods:
https://github.com/NicoHood/NicoHood.github.io/wiki/Raspberry-Pi-Encrypt-Root-Partition-Tutorial
Install snapd and the snaps you need.


How can I get all USB storage device to mount as read-only or offer no mount options at all?

Most USB flash drives are formatted with FAT32. This is a simple filesystem with no journaling or other fancy features. Data is only written if metadata or file contents get modified unless you set the mount policy to read-only. For Linux distributions, you could do this by adding the ro option when manually mounting a partition with the mount program.

You are now looking at desktop programs (Nautilus) which does not use mount directly (it does not even have permissions to do so). It likely uses UDisks instead (actually, udisks2). In the manual page udisks(8) you can find some variables that can be used with udev. To hide a partition from Nautilus for example, have a look at this answer.

I am not aware of an option to set the default mount policy, but you can certainly specify a mount option when manually mounting as root:

udisksctl mount --options ro ...

Changing the permissions of /dev/bus/XXX/YYY is nonsense. Normal users are able to mount external storage because there is a privileged daemon running (udisksd) that operates on behalf of the user.


I can't comment on a Paging file being to be created in Open Suse since I have no prior experience with it. However Swap is the paging partition for Linux.
The following is excerpted from SwapFaq (by Contributors to the Ubuntu documentation wiki):

What is swap?
Swap space is the area on a hard disk which is part of the Virtual
Memory of your machine, which is a combination of accessible physical
memory (RAM) and the swap space. Swap space temporarily holds memory
pages that are inactive. Swap space is used when your system decides
that it needs physical memory for active processes and there is
insufficient unused physical memory available. If the system happens
to need more memory resources or space, inactive pages in physical
memory are then moved to the swap space therefore freeing up that
physical memory for other uses. Note that the access time for swap is
slower therefore do not consider it to be a complete replacement for
the physical memory. Swap space can be a dedicated swap partition
(recommended), a swap file, or a combination of swap partitions and
swap files.
Why do I need swap?
Memory consuming programs Sometimes, a large program (like
LibreOffice, Neverwinter Nights, or a video editor) make the entire
system need extra memory. A significant number of the pages used by
these large programs during its startup may only be used for
initialization and then never used again. The system can swap out
those pages and free the memory for other programs or even for the
disk cache. In these cases, swap will be used to help the system
handle any extra load.
Hibernation (suspend-to-disk) The hibernation feature (suspend-to-disk) writes out the contents of RAM to the swap partition
before turning off the machine. Therefore, your swap partition should
be at least as big as your RAM size. The hibernation implementation
currently used in Ubuntu, swsusp, needs a swap or suspend partition.
It cannot use a swap file on an active file system.
Unforeseeable Circumstances Unforeseeable events can and will happen (a program going crazy, some action needing much more space
than you thought, or any other unpredictable combination of events).
In these cases, swap can give you an extra delay to figure out what
happened, or to finish what you are working on.
Optimizing memory usage Since mechanical hard drives are considerably slower than RAM (SSD - Solid State Drive - storage is not
as slow as physical drives, but still slower than RAM), when you need
a file (be it a data file like a video, executables like Firefox, or
libraries), the Linux kernel reads the file into RAM and keeps it
there, so that the next time you need it, it is already in RAM and
data access is much faster. The portions of RAM that accelerate disk
read are called "cached memory." You will notice that they make a huge
difference in terms of responsiveness. The Linux kernel automatically
moves RAM reserved by programs--but not really used--into swap, so
that it can serve the better purpose of extending cached memory.
Optimizing Swap performance Because swap space uses a disk device, this can cause performance issues in any system that uses swap space
significantly because the system itself may also be using the same
disk device at the same time that it is required for swap operations.
One way to reduce this problem is to have swap space on a different
physical drive so that the competition for that resource is either
reduced or eliminated.

For a more in-depth revision and understanding of all the components, feel free to check out the community Wiki: SwapFAQ


how to suppress ld.so.preload error messages in gnome-terminal when I launch it

I managed to pinpoint and silence the error message.
It is a warning message and causes no harm.
When I search for that bugging message I noticed that it's a well-known issue with Steam since it uses 32 bit arch.

Some even proposed a patch to get rid of the message.

In my case it's triggered by environment variable sourced from my ~/.bashrc which I added some time ago.

I found how to debug bash sourcing process in that link:

https://unix.stackexchange.com/questions/813/how-to-determine-where-an-environment-variable-came-from

At first I ran the following line in gnome-terminal

PS4='+$BASH_SOURCE> ' BASH_XTRACEFD=7 bash -xl 7>&2

It streams all the environment variable sourcing process.

Then I added the below line top of my ~/.bashrc

 set -x

It shows the hidden process of sourcing ~/.bashrc

The latter showed me  culprit line in my ~/.bashrc

It was :

  [ -s "$NVM_DIR/nvm.sh" ] && \. "$NVM_DIR/nvm.sh"

I silenced the error message with:

 [ -s "$NVM_DIR/nvm.sh" ] && \. "$NVM_DIR/nvm.sh" 2>/dev/null >/dev/null


How to download a dataset with .sh file?

There is a problem with their Google account. If you try download a file using the bash script file contains:

<?xml version='1.0' encoding='UTF-8'?>
<Error>
AccountProblem
<Message>Your Google account is not currently enabled for this operation. Please check https://console.developers.google.com/billing to see if you have a past due balance or if the credit card (or other payment mechanism) on your account is expired. You can find additional information at https://developers.google.com/storage/docs/signup
</Message>
</Error>


Do I need nvidia driver on my new dell 5720 with Ubuntu 13.04?

The nvidia-current package from the default Ubuntu repositories is the safest and most stable graphics driver to install, and it is also supported by Ubuntu software updates. The current version of nvidia-current for Ubuntu 13.04 is 304.88, and it works with Optimus. In 18.04 and later the nvidia-current package is no longer in the default Ubuntu repositories. Instead the following command will install the recommended proprietary Nvidia graphics driver and its dependencies automatically.

sudo ubuntu-drivers autoinstall && sudo reboot


How to synchronise my files over LAN (Ubuntu/Windows, I'm a novice)

Try this:
First, map the Linux share (Samba) into your Windows XP machine as follows:

Open file explorer (Right-click Start and click explore):
click Tools (drop-down menu)
click Map Network Drive
Enter the path for your share \\ubuntubox\shareName and select a drive letter to map
Click the link Connect using a different user name and enter user credentials (if required)
Click finish

Second, install FreeFileSync. With FreeFileSync, you can sync your Windows XP files to the target map drive/folder accordingly.


To check the file systems on your Linux partitions...

boot to the GRUB menu (where you select which OS to start)
choose Advanced Options
choose Recovery mode
choose Root access
at the # prompt, type sudo fsck -f /dev/sdb1
at the # prompt, type sudo fsck -f /dev/sdb5 # this command may fail
at the # prompt, type sudo fsck -f /dev/mapper/luks-bf04fb83-73a0-4679-a468-9571c05a73b0
repeat the fsck command if there were errors
type reboot


Network Issues: Ubuntu Server 16.04 on a Macmini 1,1 (Late 2006)

Well, doing a reinstall and retrying the automatic configuration over and over again eventually got it to work. If someone was able to tell me what I did wrong I would appreciate it, but the automatic configuration was able to fix it in the end.


Evince "Open Containing Folder" shows "Could not open the containing folder" (Permission denied)

AppArmor is restricting the permissions of evince.

Firstly, add the following line to the file /etc/apparmor.d/usr.bin.evince:

  /usr/bin/caja Cx -> sanitized_helper,     # Mate

and save it.

Then restart the AppArmor service as follows:

sudo service apparmor restart

This will resolve the issue.

For other file managers one of the following example configurations can be applied:

  /usr/bin/nautilus Cx -> sanitized_helper, # Gnome
  /usr/bin/pcmanfm Cx -> sanitized_helper,  # LXDE
  /usr/bin/krusader Cx -> sanitized_helper, # KDE
  /usr/bin/thunar Cx -> sanitized_helper,   # XFCE

Multiple lines, as seen above, are allowed as well.


Desktop launcher for script in terminal containing sudo command

Found a Solution:

myfile.desktop

[Desktop Entry]
Version=1.0
Name=Tester
Comment=Debug
Exec=gksu "gnome-terminal -x bash -c /home/me/Desktop/myscript.sh"
Icon=utilities-terminal
Terminal=false
Type=Application
Categories=Application;

myscript.sh

#!/bin/bash

PID=$(pidof mysoftware)

sudo strace -p$PID -s9999 -e write
$SHELL


Disabled WiFi but it keeps re-enabling itself; want it to stay disabled

Fire up the terminal and type this

rfkill list all

Note Down the number corresponding to wlan and use this command

rfkill block 1

replace 1 with the number of your wireless card


option like TAIL to keep track of WHOLE file

man tail gives :

tail -F or tail --follow=name --retry to keep tail watching file even if all the file is rewritten.


ubuntu 16.04 refuses to run with GEForce GTX1650

After a lot of reading and trying many things including trying to load 18.04 I tried 'xrandr' and was informed there was no graphics card. I replaced the GTX1650 with the old GTX750ti , reinstalled 16.04, nvidia driver(384) installed and resolution went from 1360x768 to 1600x900 as it should be. Problem solved for me for the time being.


Brightness control not working on laptop ubuntu16.10

I finally found the answer to my problem :

I followed the instructions on this page I did not found during my researches :

https://help.ubuntu.com/community/HybridGraphics

So, assuming the situation described above,  go into the "additional drivers" section of ubuntu, I switched to 367.57 driver, and in the /etc/default/grub ,
change this line :

GRUB_CMDLINE_LINUX_DEFAULT="quiet splash"

to this :

GRUB_CMDLINE_LINUX_DEFAULT="quiet splash modeset=nouveau"


Why delete .hidden folders in home when reinstalling broken programs?

Well, typically, those folders contain program's user-specific settings. I.e. those settings that are set on a user-by-user basis. For example, in Skype that would be your personal account, notification, audio/video settings etc. Unfortunately, this is often the case that some of the settings get messed up and it is quite hard to figure out what exactly is wrong. In that case it may be advised to just delete the whole folder to bring it back to the initial state.

There are also other typical folders containing you program P settings, such as ~/.P, ~/.config/P, ~/.gnome2/P, ~/.gconf/apps/P etc. It all depends on where a particular program stores its settings. When you remove a corresponding folder all the settings for the program are gone.

Now, I believe, this also answers the question why the programs do not do that by themselves.


How to install Ubuntu Server over Ubuntu Desktop on my mac?

Put the disk in the computer, run the disk, go through the install steps until you get to disk partitioning then make sure you have the install delete the ubuntu (ext3 or ext4) and swap partitions (if you don't care about osx then wipe that to) then continue as usual. Frankly if you don't care for anything on that drive you have really don't have to do anything beyond clicking next a few times.


Upgrade to 14.04 causes "the disk drive for /dev/mapper/cryptswap1 is not ready yet or not present" - Computer can't start: Live Disc Repair Option?

I had to give up after finding my paper backup for the bitcoins. Before that, I tried reinstalling GRUB, created a new SWAP, and nothing worked. I wish anyone else with this issue the best of luck.


There is no actual need to flush DNS as Ubuntu doesn't cache DNS. Instead, your ISP may be caching DNS. If you want to enable DNS cache, install pdnsd and resolvconf.


Sound stopped working after crash Ubuntu 20.04

/var/lib/alsa/asound.state appears to be corrupted, empty or has permissions issues.
To fix this, run in the terminal:
sudo mv /var/lib/alsa/asound.state /var/lib/alsa/asound.state.old

then, run:
sudo alsactl --file /var/lib/alsa/asound.state store

then, run:
sudo alsa force-reload

then, run:
mv  ~/.config/pulse/ ~/.config/pulse_old/

then, run:
pulseaudio -k

or just reboot your system.
If that didn't work, check the alsamixer settings as in this answer then repeat the above steps.


How do you change your screen's color temperature?

redshift -O 5000 works for instantly turning on warm mode instead of messing with location data


Can't ping two laptops through ad-hoc network

my first guess would be the ufw settings.   in other words, the reverse ping might be prevented by the firewall on the one that is "unreachable).  You can run "sudo ufw status" to check the current rules (and also whether it's enabled).
I'm also a bit puzzled by the IP assignments.  I do something similar to this, with the router hard wired to one of the laptops, and the router (netgear) always assigns the *.1.1 address to itself.  If you've set the IP addresses internally, rather than via DHCP, then that might be a problem, too, if there is an IP address conflict on your mini-net.  I have one of the nodes set up as 1.4, and then the others get assigned higher in the mask range.  (We have up to 10 on the net, actually.)  If there is a conflict, it could actually block both directions, since one way the first step would be blocked and the other way the ACK could be blocked (because it goes the wrong place).  Make sure that there aren't any conflicts on the net, INCLUDING the router.


Wifi not found on fresh install for Acer VivoBook Pro 17

Am I even on the right track?

You are very close but you’ve missed a very important clue. The essential element in identifying the correct driver is the pci.id, usb.id or similar. You can find the pci.id for your device with the terminal command:

lspci -nnk | grep 0280 -A3

We suspect that you will find that it is: Realtek Semiconductor Co., Ltd. Device [10ec:b822]

When we search this very site for 10ec:b822, we find this answer: Asus Rog Strix Z370 EGAMING Wireless card not working

Therefore, I suggest that you follow the same procedure; with a temporary working internet connection, do:

wget https://github.com/lwfinger/rtlwifi_new/archive/extended.zip
unzip extended.zip
cd rtlwifi_new-extended
make
sudo make install
sudo modprobe rtl8822be

If, after the 'make' step, you have errors, please post them here. Warnings are probably alright.

You will have compiled the driver for your current running kernel only. When Update Manager installs a later one, also known as linux-image, after the requested reboot, re-compile:

cd ~/rtlwifi_new-extended
make clean
make
sudo make install
sudo modprobe rtl8822be


how can install SkyStar 2 PCI DVB on ubuntu 14.04 x86_64?

From this source on linuxtv.org,

you need to install a driver for your DVB Card:

sudo apt-get install build-essential gcc make mercurial linux-headers-`uname -r`

Get the latest source code of Video4Linux and the TechniSat diver, extract these and apply the patch:

hg clone -r 9976 http://linuxtv.org/hg/v4l-dvb
wget http://skystar-2.com/server.php?filename=1721.tar.bz2
tar xfj 1721.tar.bz2
cp skystar2-rev2.8-v4l-dvb-files-2008-07-09/skystar2-rev2.8-v4l-dvb.patch v4l-dvb/

For 32bit:

cp skystar2-rev2.8-v4l-dvb-files-2008-07-09/cx24113_blob.o.i386 v4l-dvb/v4l/cx24113_blob.o_shipped

For 64bit:

cp skystar2-rev2.8-v4l-dvb-files-2008-07-09/cx24113_blob.o.x86-64 v4l-dvb/v4l/cx24113_blob.o_shipped

Now continue with:

cd v4l-dvb

Apply the patch to Video4Linux:

patch -p1 < skystar2-rev2.8-v4l-dvb.patch

Awnser no to any questions asked(default):

make
sudo make install

Now reboot and after that your sat card should be ready to go


How can I easily install ncview in 17.04?

Use synaptic or

sudo apt-get install ncview


I finally figured out in this thread: How to control Brightness
Just to keep it straight

Run the following command in Terminal:
sudo gedit /etc/default/grub

then change
GRUB_CMDLINE_LINUX_DEFAULT="quiet splash"
GRUB_CMDLINE_LINUX=""

to
GRUB_CMDLINE_LINUX_DEFAULT="quiet splash acpi_backlight=vendor"
GRUB_CMDLINE_LINUX="acpi_osi=Linux"

then save and run:
sudo update-grub

and then restart the system for changes to take effect.


Cant boot win7. Boot loader installed on SSD

try repairing grub via boot-repair booting into live usb of ubuntu, make sure repair windows boot files is checked under Advenced/Other Options. Than you'd be good to go.


Tried switching to Ubuntu and cannot get back to Windows

A few questions and simple things to try:

Have you ever installed Ubuntu or any additional operating system other than Windows on this laptop?

If you are trying Ubuntu off the flash drive you mention have you tried booting with the flash drive removed? If so what happens?

Have you tried pressing {delete}, F2 or F12 while booting. In my experience if you are in legacy mode one of these will take you to the bios.

Would be useful to see the output of lsblk (run in the Ubuntu terminal)

Hope this helps


Where does XFCE store the keyboard shortcuts?

The configured keyboard shortcuts should be in:

/home/username/.config/xfce4/xfconf/xfce-perchannel-xml/xfce4-keyboard-shortcuts.xml


How to disable NetworkManager on Ubuntu 15.10?

I found this bug report with information on disabling it - https://bugs.launchpad.net/ubuntu/+source/network-manager/+bug/82335 Post #19

Could you uninstall NetworkManager and use apt-get download network-manager to download only? (In case you need it later, you could install while offline) This would download to the current directory, so you may want to move it.

Also, what problem are you having that you need to disable it?


Find, Duplicate, Rename and Copy to this folder

Here is example script that users find, which output is piped to a while loop:

find "/mnt/TV Shows/" -type f -name "fanart.jpg" | while IFS= read -r item; do
    NAME="${item##*/}"
    echo cp "$item" "/mnt/Wallpapers/Slideshow/${NAME%.*}-$((i++)).${NAME##*.}"
done

Remove echo the do the action.
The name of the destination file will consist of:

${name of source file}-$((sequential number))-${extension of source file}

The numbering will start from 0, because the variable $i has not been pre-initialized. You can put i=1; before find to start numbering from 1.

Here is more complicated bash script that uses  the globstart option ** to make recursive search for a file within a folder. If there is a coincidence the file will be be copied to a destination folder. You can choice between different patterns of the destination file name by changing the inner (if-fi) part of the script.

#!/bin/bash

INPUT_PATH="/mnt/TV Shows"
INPUT_FILE_NAME="fanart.jpg"
OUTPUT_PATH="/mnt/Wallpapers/Slideshow"

shopt -s globstar

for item in "${INPUT_PATH}"/**; do
    # If the item is a file and its name is equal to the INPUT_FILE_NAME
    if [[ -f "$item" && "${item##*/}" == "$INPUT_FILE_NAME" ]]; then
        # Compose OUTPUT_FILE name based on the parent directory name
        INPUT_FILE_FULL_PATH="${item%/*}"
        INPUT_FILE_PARENT_DIR="${INPUT_FILE_FULL_PATH##*/}"
        OUTPUT_FILE_NAME="${INPUT_FILE_NAME%.*}-${INPUT_FILE_PARENT_DIR}.${INPUT_FILE_NAME##*.}"
        # Remove 'echo' to execute the command !!!
        echo cp "${item}" "${OUTPUT_PATH}/${OUTPUT_FILE_NAME}"
    fi
done

References:

While loop only processes the first entry of ssh command
Recursive bash script to collect information about each file in a directory structure


Ubuntu not loading after login screen after an incomplete upgrade of 15.10

Are you using gdm? If so, try switching to lightdm:

sudo service gdm stop && sudo dpkg-reconfigure lightdm
sudo service lightdm start

It could also be an issue with the permissions on your .Xauthority file. To solve that, refer to this question: https://askubuntu.com/a/223634/470880

However, if you believe that it was an upgrade issue, perhaps using a USB/CD to re-install Ubuntu 15.10 would fix the issue.


What is the equivalent user for nobody:nobody from CentOS?

You can use nobody:nogroup if you really do want a user/group with no permissions.  But Debian derivatives tend to define a user and/or group per task to ensure that your unprivileged services are separated from each other.


You may be running QtCreator on an old CPU that's missing SSE2 instructions, hence the "illegal instruction" message. See this question on archlinux:https://bugs.archlinux.org/task/34228 .

However, I don't know if it possible to recompile recent QtCreator (2.7) so that it doesn't use SSE2 instructions.


How to recover data from a thrice formatted HDD?

it still may be possible to recover.  Checkout the wiki here:

https://help.ubuntu.com/community/DataRecovery

TestDisk is my go to app for such things:

http://www.cgsecurity.org/wiki/TestDisk_Step_By_Step

I would boot into a live ubuntu cd / usb drive and install testdisk.

sudo apt-get install testdisk


I agree with kyleN's answer regarding why typing a wrong command in terminal takes longer then starting an existing program.

A pause after entering a wrong password, however, is a completely different matter - this delay is introduced intentionally to prevent brute-force password attacks (i.e. trying thousands of passwords a second until one matches). Adding a small delay when an incorrect password is entered doesn't affect usability for "real" users but makes such attacks completely impractical. So yes, in this case it's a security measure.


Can't run Frama-C on 13.04 after installation

Try frama-c-gui in a terminal.

frama-c is a command line application and does not have graphical front end.

frama-c-gui is a graphical front end to it and is installed when you install frama-c

From the Man Page

DESCRIPTION

frama-c  is  a  suite of tools dedicated to the analysis of source code written in C.  It gathers  several  static  analysis  techniques  in  a single  collaborative  framework.  This  framework  can  be extended by additional plugins placed in the $FRAMAC_PLUGIN directory. The command

frama-c -help will provide the full list of the plugins that are currently installed.

frama-c-gui is the graphical user interface of  frama-c.   It  features the same options as the command-line version.

frama-c.byte and frama-c-gui.byte are  the  ocaml  bytecode versions of the command-line and graphical user interface respectively.

By default, Frama-C  recognizes  .c  files  as  C  files  needing  pre-processing  and  .i files as C files having been already pre-processed. Some plugins may extend the list of  recognized  files.  Pre-processing can be customized through the -cpp-command and -cpp-extra-args options.


I just want to remove the file from directory

Use sudo

sudo rm rm /usr/local/mongodb/*

See https://help.ubuntu.com/community/FilePermissions

and

https://help.ubuntu.com/community/RootSudo

for additional information


this is a simple lanucher for Audacity:
[Desktop Entry]
Version=1.0
Name=Audacity
Comment=Musical Editor
Exec=audacity
Terminal=false
X-MultipleArgs=false
Type=Application
Icon=audacity
StartupNotify=true


Step 1:

Open a terminal if necessary with CTRL+ALT+T

Step 2:

logon as root

sudo -i

Step 3:

Check the path

echo $ANDROID_SDK_HOME

Step 4:

If you opened a terminal at step one close it and you are no longer root; otherwise log out as root

exit


How to run multiple Python files by running one terminal code?

You don't need to copy the script to each directory. Just modify the find command to run it instead:

find allen-p ... zufferli-j -maxdepth 1 -type d -execdir python "$PWD"/file.py \;

The -execdir option runs the command inside each directory. We use $PWD to give the full path to the script, so that a changing working directory doesn't affect where the command looks for the script.

However, since you have copied it anyway, you can skip the $PWD:

find allen-p ... zufferli-j -maxdepth 1 -type d -execdir python file.py \;

Note

You didn't provide a type check in your find command (like I did with -type d above). Without it, every file in those directories has now been overwritten with file.py. You only want to copy to (and run in) directories, so you should have added a -type d to it.


If you have the device connected via an USB-hub (or even an extra cable), remove it from there...
and connect it to an USB connector in your computer (no extras between!).


12.10 Booting Into Variations Of Blank Screen

I just clean installed 12.10 with updates during install and anything other that the default nouveau driver results in problems (nvidia based card). The nouveau driver also has a problem.

So yes, either they need send out updates that fix it or you do what I did and go back to 12.04. 12.10 is problem city atm.


Moving the Workspace Switcher Pop up location from center of the screen requires editing the gnome-shell core files which is very hard.

Instead you can little bit tweak the sizes and colors.

Ubuntu 18.10 with default User-Shell theme.

after Tweaking

to tweak it, i have edited the file /usr/share/gnome-shell/theme/Yaru/gnome-shell.css

Original Content

/* Workspace Switcher */
.workspace-switcher-group {
  padding: 12px; }

.workspace-switcher-container {
  padding: 5px;
  border-radius: 6px; }

.workspace-switcher {
  background: transparent;
  border: 0px;
  border-radius: 0px;
  padding: 0px;
  spacing: 8px; }

.ws-switcher-active-up, .ws-switcher-active-down {
  height: 50px;
  background-color: rgba(247, 247, 247, 0.4);
  color: #ffffff;
  background-size: 32px;
  border-radius: 6px; }

.ws-switcher-active-up {
  background-image: url("ws-switch-arrow-up.svg"); }

.ws-switcher-active-down {
  background-image: url("ws-switch-arrow-down.svg"); }

.ws-switcher-box {
  height: 50px;
  border: 1px solid rgba(247, 247, 247, 0.1);
  background: rgba(247, 247, 247, 0.1);
  border-radius: 6px; }

.osd-window,
.resize-popup, .switcher-list, .workspace-switcher-container {
  color: #F7F7F7;
  background-color: rgba(29, 29, 29, 0.975);
  border: 1px solid rgba(255, 255, 255, 0.13);
  border-radius: 12px;
  padding: 12px;
  box-shadow: 0 3px 9px 1px rgba(0, 0, 0, 0.5); }

Edited Content

/* Window Cycler */
.cycler-highlight {
  border: 5px solid #E95420; }

/* Workspace Switcher */
.workspace-switcher-group {
  padding: 12px; }

.workspace-switcher-container {
  padding: 5px;
  border-radius: 6px; }

.workspace-switcher {
  background: transparent;
  border: 0px;
  border-radius: 0px;
  padding: 0px;
  spacing: 8px; }

.ws-switcher-active-up, .ws-switcher-active-down {
  height: 50px;
  background-color: blue;
  color: #ffffff;
  background-size: 32px;
  border-radius: 6px; }

.ws-switcher-active-up {
  background-image: url("ws-switch-arrow-up.svg"); }

.ws-switcher-active-down {
  background-image: url("ws-switch-arrow-down.svg"); }

.ws-switcher-box {
  height: 5px;
  border: 1px solid rgba(247, 247, 247, 0.1);
  background: green;
  border-radius: 6px; }

.osd-window,
.resize-popup, .switcher-list, .workspace-switcher-container {
  color: #F7F7F7;
  background-color: transparent;
  border: 1px solid rgba(255, 255, 255, 0.13);
  border-radius: 12px;
  padding: 0px;
  box-shadow: 0 3px 9px 1px rgba(0, 0, 0, 0.5); }

you can make your customization based on above.


How to know last time `apt-get update` was executed?

Check the time stamp of /var/lib/apt/periodic/update-success-stamp.

$ ls -l /var/lib/apt/periodic/update-success-stamp
-rw-r--r-- 1 root root 0 Jan 25 01:41 /var/lib/apt/periodic/update-success-stamp

Here the time is Jan 25 01:41 when apt-get last executed. To get the time only, use the following command in terminal,

$ ls -l /var/lib/apt/periodic/update-success-stamp | awk '{print $6" "$7" "$8}'
Jan 25 01:41

It is the best place to check the last update time. If you found /var/lib/apt/periodic/ to be empty you can try,

ls -l /var/log/apt/history.log

Update

It is found that due to some reasons above files update-success-stamp or history.log remain unavailable in some systems. There is a new proposal from derobert  to look into the file /var/cache/apt/pkgcache.bin.

pkgcache.bin is Apt's memory mapped package cache location. It get renewed after each update. So it is the perfect candidate to know the last time when apt was updated.

One can use the following command to know the exact time,

ls -l /var/cache/apt/pkgcache.bin | cut -d' ' -f6,7,8

or

stat /var/cache/apt/pkgcache.bin


These fields in the /etc/passwd file are called GECOS fields. Unfortunately, I cannot find a single command to get this single field such as the full name. I believe this cannot be done without using shell scripting. Below are two approaches.

Parse passwd directly:

getent passwd $USER | cut -d ':' -f 5 | cut -d ',' -f 1
Gert van Dijk

Use of finger

finger -m $USER | head -n 1 | sed 's/\(.*\)Name\:\s\(.*\)$/\2/g'
Gert van Dijk

Related question on SO: What's the easiest way to get a user's full name on a Linux/POSIX system?

For programming in C, this is more elegant by using getpwnam().

But really, for use in Git for a single user do:

git config --global user.name "Your Full Name"
git config --global user.email "user@example.tld"


Wired connection problem (Ubuntu 13.04, Realtek RTL8111/8168 Ethernet controller)

Press Ctrl+Alt+T and then enter this in the command prompt :

echo on | sudo tee /sys/class/net/eth0/device/power/control


Get magnet link to open with download center on LAN connected nas

i resently found out that this is possible via transmission remote
(this should work since download center is transmission based )

Unfortunately i will still need to figure out how exactly!
at the moment i don't have time for that.. but i will edit this answer as soon as i have found out.


How get latest version of Baloo on Ubuntu?

After adding the mentioned PPA you have to try to install the Baloo KF5 package with:

sudo apt-get install baloo-kf5

To get all new dependencies you have to also run:

sudo apt-get dist-upgrade

after adding the PPA.

But be careful, enabling KDE backports PPAs is a bit dangerous on downgrade by
ppa-purge ppa:kubuntu-ppa/backports.


Pros and cons of Cinelerra vs Adobe Premiere Pro

Cinerella is free software. You can try it for free and if you don't like it, it costs you nothing.
Cinerella is maintained by updates. A new version of Cinerella for Ubuntu for 2014 is coming soon. If you buy Adobe Premiere Pro CS6, within a few years the latest version of Cinerella will be better than the version of Adobe Premiere Pro CS6 that you bought.
Cinelerra-CV (the community version) packages for Ubuntu are available from the "Cinelerra-CV" team PPA. Instructions for adding this PPA to your system can be found at the same link.

Source: Cinerella official website


Open up "startup disk creator".
Plug in your USB pendrive.
Click to erase all data on the device.
Exit startup disk creator.
Unplug the device and plug it back in and you should now be able to use the device.

This also works after using dd.

Alternatively, I'm pretty sure you can do this to reformat the drive: warning, this will delete all content on the device so make sure you specify the correct device!

sudo mkfs -t vfat -I /dev/sdx

where /dev/sdx is the actual device.

In your case, it looks like it should be /dev/sdc:sudo mkfs -t vfat -I /dev/sdc

UPDATE

According to this similar question with the same error, you should be able to completely wipe the entire device using the following command:

sudo dd if=/dev/zero of=/dev/sdx
sudo mkfs -t vfat -I /dev/sdx

Where /dev/sdx is the actual device. In this particular case, your device appears to be /dev/sdc so you should run:

sudo dd if=/dev/zero of=/dev/sdc
sudo mkfs -t vfat -I /dev/sdc


I'm fairly new to this myself, but hopefully this helps:

If you put two NICs in your master node, you can have one of those connected to the outside world and then connect the other one to the switch which would connect to all of your compute nodes.  You would want to run DCHP to serve out IPs to all of the nodes and DNS so that people won't have to know the IPs of the nodes to ssh/rsh to them. Dnsmasq is the easiest way to get these two services running.

In /etc/network/interfaces add something like:

# The primary network interface
auto eth0
iface eth0 inet dhcp

# The inside network interface - To the Nodes
auto eth1
iface eth1 inet static
address 192.168.0.254 #(I set the master to 254 so node1 can be .1, etc)
netmask 255.255.255.0
network 192.168.0.0
broadcast 192.168.0.255

In /etc/dnsmasq.conf make sure you define interface=eth1 (the inside network) so you're not trying to serve IPs to the outside world.

In /etc/hosts add the lines for your compute nodes:

...
192.168.0.1    node1.<domain>   node1
192.168.0.2    node2.<domain>   node2
...


What cowsay characters does Ubuntu have by default and how can I test them?


Download the alternate installation CD
Burn the ISO to a CD and insert it into the CD drive of the computer to be upgraded.
If the ISO file is on the computer to be upgraded, you could avoid wasting a CD by mounting the ISO as a drive with a command like:

sudo mkdir -p /media/cdrom
sudo mount -o loop ~/Desktop/ubuntu-11.04-alternate-i386.iso /media/cdrom

  (make sure you use the actual filename of the iso you downloaded ^^^^ )

A dialog will be displayed offering you the opportunity to upgrade using that CD.
Follow the on-screen instructions.

If the upgrade dialog is not displayed for any reason, you may also run the following command using Alt+F2:

gksu "sh /media/cdrom/cdromupgrade"

Or if you're using Kubuntu run the following command using Alt+F2:

kdesudo "sh /media/cdrom/cdromupgrade"


Can't move Screenlets when position is set to "Keep Above"

Right click on the gadget then in the popup menu go to Windows and click on keep below.

This could fix your problem! ;)


According to the outputs you provide, the cryptswap should be working. The swapon -s reports that you do have a 6 GB swap file mounted at /dev/mapper/cryptswap1 (lucky you, for some this does not happen).

The free -m output says that out of the 6 GB of RAM, only about 2.2 GB is currently being used and your swap is empty. This is OK since swap starts filling up only after the operating system has allocated most of the RAM to programs and cache.


Can't connect to any wifi network on Ubuntu 18.04.3

try one or all of the following:

Restart network manager:
sudo systemctl restart NetworkManager

Rescan for available wifi's:
iwlist  scan

Turn wifi on and off
nmcli radio wifi off && sleep 5 && nmcli radio wifi on


Volume level not remembered after shutdown/restart

It may be a problem in your pulseaudio settings. Try renaming the ~/.pulse directory:

mv ~/.pulse ~/.pulsebak

Then reboot, and see if it helps.


Solution described here worked perfectly http://www.askubuntu.com/a/279549/261002


iPhone mounting problem: idevicepair command not found

Try installing the package libimobiledevice-utils available in the software center

i.e.

in a terminal type:

sudo apt-get install libimobiledevice-utils


Here is what you should do now:

Go download boot repair disk from this link.
Put it in USB via Unetbootin.
OR you can always burn it to CD.
Boot from the newly created media (USB or CD).
Go through simple steps like selecting language etc. then 'Boot repair' dialog will appear; select 'Recommended Repair' and re-boot your PC.
Now its done.


You are missing the package gstreamer0.10-ffmpeg. It is, however, not available in the 14.04 repositories, so you can get it from a PPA:

sudo add-apt-repository ppa:mc3man/trusty-media
sudo apt-get update
sudo apt-get install gstreamer0.10-ffmpeg


Changed ownership of sudo and now I need to save files from the computer to reinstall

Possible best and easiest method: you can use a live cd to burn that tar file to a CD or DVD. Since it will use the live cd's /usr/bin it will be able to use the dvd/cd player. Just mount the disc that has the tarfile and burn it.

Alernative to try and do it from your system:

Reboot the machine.
Press the ESC key while GRUB is loading to enter the menu.
If there is a ‘recovery mode’ option, select it and press ‘b’ to boot into single user mode. Otherwise, the default boot configuration should be selected. Press ‘e’ to edit it.
Highlight the line that begins with ‘kernel’. Press ‘e’ again to edit this line.
At the end of the line, add an additional parameter: ‘single’. Hit return to make the change and press ‘b’ to boot.

Commands to reset sudo file:

chown root:root /usr/bin/sudo
chmod u+s /usr/bin/sudo

Reboot and try to burn the tar file (hopefully only the wrong permissions for sudo is the problem).


I can't download anything in Ubuntu system

Aptitude is amazing !!! It has solved many such issues.
Try using it: sudo aptitude install <package-name>.
or
You may even try sudo aptitude dist-upgrade.
FYI - This requires aptitude to be installed. If you don't have it run sudo apt-get install aptitude.
Good luck


Hiding mouse after being few seconds idle on X display

There is an application called unclutter that will do it.  Install it by typing in the following at a terminal window:

sudo apt-get install unclutter

after it is installed, you can change the timeout to 2 seconds in the following file:

/etc/default/unclutter

and change the following line:

EXTRA_OPTS="-idle 1 -root"

to

EXTRA_OPTS="-idle 2 -root"

this also auto-starts when the system boots up.

To have it start now without the system restarting, type in the following:

nohup unclutter -idle 2 &

EDIT:

If it is not found for install, edit your /etc/apt/sources.list file and make sure that the following lines are not commented # out:

deb http://us.archive.ubuntu.com/ubuntu/ trusty universe
deb-src http://us.archive.ubuntu.com/ubuntu/ trusty universe
deb http://us.archive.ubuntu.com/ubuntu/ trusty-updates universe
deb-src http://us.archive.ubuntu.com/ubuntu/ trusty-updates universe

If they are commented out, remove the # on the front of the line, then run sudo apt-get update to update the repositories, then rerun the sudo apt-get install unclutter.

If I run the following commands, we can see that the unclutter application comes from the trusty universe repositories.

:~$ apt-cache showpkg unclutter
Package: unclutter
Versions:
8-19 (/var/lib/apt/lists/us.archive.ubuntu.com_ubuntu_dists_trusty_universe_binary-amd64_Packages) (/var/lib/dpkg/status)
 Description Language:
                 File: /var/lib/apt/lists/us.archive.ubuntu.com_ubuntu_dists_trusty_universe_binary-amd64_Packages
                  MD5: f0e9ff67c42a9d3dc35bb595d2f84a7b
 Description Language: en
                 File: /var/lib/apt/lists/us.archive.ubuntu.com_ubuntu_dists_trusty_universe_i18n_Translation-en
                  MD5: f0e9ff67c42a9d3dc35bb595d2f84a7b

:~$ dpkg -s unclutter
Package: unclutter
Status: install ok installed
Priority: optional
Section: x11
Installed-Size: 76
Maintainer: Ubuntu Developers <ubuntu-devel-discuss@lists.ubuntu.com>
Architecture: amd64
Version: 8-19
Depends: debconf (>= 0.5) | debconf-2.0, libc6 (>= 2.3.4), libx11-6
Conffiles:
 /etc/X11/Xsession.d/90unclutter 9b47a483264cfc6a155fbd65cd8a3e6e
Description: hides the mouse cursor in X after a period of inactivity
 unclutter hides your X mouse cursor when you don't need it, to prevent it
 from getting in the way. You have only to move the mouse to restore the
 mouse cursor.
Original-Maintainer: Axel Beckert <abe@debian.org>
Homepage: ftp://ftp.x.org/contrib/utilities/

Hope this helps!


To put it shortly, gnome-terminal.wrapper is a perl script that sets up the arguments for gnome-terminal and then runs exec call that spawns gnome-terminal with  those arguments.

Wrapper scripts are very frequently used to set up environment for different  applications and other scripts.

Loosely related to this question are What is a terminal wrapper? and Ctrl-Alt-t opens root terminal instead of normal terminal


What is happening is that nautilus itself is always running in the background. If you start a new nautilus instance, it will just "attach" to the previously running instance of nautilus, then close itself. That is why it is disappearing from the launcher.

Try opening nautilus with Alt + F2 like you said, right click it, then hit "Lock to Launcher".

This should make it so that it won't disappear from the launcher, but it will also stay there the entire time.

You can also killall nautilus then try opening it from the launcher. Since there are no longer any more instances when you start it, it should stay open.


Chromium-Browser starts with unmaximized window

I think you need to modify your .desktop file for Chromium, wherever it is located. It could be in ~/.local/share/applications or in /usr/share/applications. The former location is better from the point of view of ease of editing because no sudo is needed, and the .desktop file here isn't over-written with each update.

I use Chrome and not Chromium so you need to find the appropriately named .desktop file for Chromium in either of the two locations I mentioned.

To edit the .desktop file when you find it, don't double-click on it. Instead, right-click and choose the editor you prefer. As I mentioned, you may need to use sudo or gksudo depending on where your .desktop file is. (I prefer the terminal route for minor edits in which case I would use sudo nano google-chrome.desktop or just nano google-chrome.desktop, whichever is appropriate.)

Anyway, look for the line that begins with Exec= and change the contents to look like this:

Exec=/opt/google/chrome/google-chrome --start-maximized %U

keeping in mind the path that Chromium is installed in may differ and the actual name will be different, possibly chromium-browser.

In short, adding --start-maximized to the command should do the trick for this particular software.


you can put NIC on PCI and PCI-express socket


Have both proprietary drivers and open source drivers at the same time

Provided you've installed the proprietary drivers correctly, the file to disable nouveau (the open source Nvidia driver included in Ubuntu) is in

/etc/modprobe.d/nvidia-blacklists-nouveau.conf

or on your system it might be

/etc/modprobe.d/blacklist-nouveau.conf

The line that disables nouveau is

blacklist nouveau

However, you may also need/have the following lines:

blacklist lbm-nouveau
options nouveau modeset=0
alias nouveau off
alias lbm-nouveau off

Removing those line[s] should allow nouveau to run.

Now that I've answered your question, I'm going to give you some advice: do not do this. There is a very small chance you will get the GUI to work at all if you re-enable nouveau while you have the proprietary drivers installed. They are not designed to be run side-by-side. In addition, I cannot think of any situation in which you are required to use nouveau and not the proprietary driver. Any situation where nouveau runs, the proprietary driver should as well - and the proprietary driver will work in all the areas that nouveau does not.

I'm not entirely sure what you remember, but my personal recommendation is if you play any games or do anything with graphics, just use the proprietary driver. You'll save yourself a lot of headaches and time.


Using your parameters, and your "one option per line", a two pass encode looks like:

ffmpeg \
-y \
-i '/media/levan/BEEA60D8EA608E89/Downloads/Videos/Tony Braxton - Un-Break My Heart.VOB' \
-s 1920x1080 \
-aspect 16:9 \
-r 25 \
-b 15550k \
-bt 19792k \
-vcodec libtheora \
-an \
-f ogg \
-pass 1 \
/dev/null \
&& \
ffmpeg \
-y \
-i '/media/levan/BEEA60D8EA608E89/Downloads/Videos/Tony Braxton - Un-Break My Heart.VOB' \
-s 1920x1080 \
-aspect 16:9 \
-r 25 \
-b 15550k \
-bt 19792k \
-vcodec libtheora \
-acodec libvorbis \
-ac 2 \
-ar 48000 \
-ab 320k \
-pass 2 \
ddd.ogg

You can exclude the audio from the first pass and output to /dev/null (as in the example). I don't see any reason why you need three passes.


Problems with run from USB installation creation and lack of option to run from USB

At first I suggest preparing your USB with the Linux Live USB Creator. I've done this last week and have had your missing try-option after booting from USB. The process of preparing your USB-drive properly is seperated into easy and comprehensive steps. All you need is an ubuntu image (e.g. the one have downloaded already) and an USB-drive.

Also the bootloader (i.e. grub 2 for ubuntu 12.04) operates very well IMO. It should detect your Windows installation automatically and add it to boot menu. Just get yourself familiar with some manuals and tutorials and you'll soon get enough confidence to press the all-mighty Install-button ;-)


Slow performance with Ubuntu 18.04 after more then a year using and developing with it

There is a possibility that you're looking at the software and it could be hardware based.

Many slowdowns are actually caused by the hard disk, especially HD (spinning disks).  If you've got a fairly full drive it'll be spending more time searching for the correct blocks to read. When you wipe the drive it's back to being fresh with barely anything on it. The more programs and files you create the slower it will get as it has way more to search through (I've really simplified how disks & file systems work).

The best way around this I would suggest is putting a SSD to install the OS on to in the machine and using the large HDD for file storage (/home).


File permission resets after reboot (Ubuntu 18.04)

The problem was solved once I formatted the storage HDD with an ext4 filesystem.


openafs module build problem kernel 3.12.6 under 13.10

At the time that you installed openafs, I think the openafs package didn't support building against that kernel; this is LP #1246675. According to that bug report, this issue was fixed with a new version of the openafs package, so the solution is to upgrade. Or, more generally, to apply the following three patches, referenced in that bug:

http://git.openafs.org/?p=openafs.git;a=commitdiff;h=70790f87b7b0ef3746c043a868c4306e05008ecd
http://git.openafs.org/?p=openafs.git;a=commitdiff;h=30160ad6eec3c290a770b6069fc106f452e5b4ba
http://git.openafs.org/?p=openafs.git;a=commitdiff;h=8f88530289297117b001d81843e3ac23564815d0


LibreOffice Writer - export as PDF - disable copying of content

If you want to stop your text from being copied, the only way is to first turn them into images and then turn them back in PDF. It's easy:

you need a PDF editor like Adobe Acrobat or in Ubuntu, nothing works better than Master PDF Editor. Open your PDF file with it and go to:

  File> Export to> Images

then select the format (like jpg) and directory.

Open the terminal and go to the directory you saved the images and type:

convert *.jpg output.pdf

There you have a perfect PDF!


WiFi option disappeared after installing updates in Ubuntu 12.10

I had the same problem on my laptop. I have run these commands and afther that it worked:

sudo apt-get install linux-headers-generic
sudo apt-get install --reinstall bcmwl-kernel-source
sudo modprobe wl


try to recompile with this patch:
https://github.com/hellnest/xf86-video-sismedia-0.9.1/commit/60823291

solved the problem for me


X fails to start after update with reboot on Ubuntu 14.04

The line

modprobe: ERROR: could not insert 'nvidia_352': Required key not available

had the right clue.  In a nutshell, the new kernel appears to not load unsigned third party modules (the Nvidia driver in my case).  Disabling Secure Boot in the UEFI (BIOS) settings solved the problem.  This answer helped me disable Secure Boot for my ASUS board a little faster.

This answer has good background, a possible alternative solution, and mentions the problem starts with kernel 4.4.0-20.  In my case (Ubuntu 14.04), the kernel that caused problems is 3.16.0-77.


How to install gpt fdisk 8.4 in Kubuntu 12.04

It is available here now:

https://launchpad.net/ubuntu/+source/gdisk/0.8.4-1
“gdisk” 0.8.4-1 source package in Ubuntu

Ubuntu “gdisk” package - 0.8.4-1

New upstream release:

Fix FTBFS with gcc-4.7 (Closes: #667177)
Drop debian/patches/eof_stdin.diff, accepted upstream
Refresh debian/patches/manpages.diff (minor typo fixed upstream)

Uploaded by:
    Guillaume Delacour on 2012-04-20


No visible files with ifuse ubuntu 20.04

There is a bug in ifuse with ubuntu 20.04
https://github.com/libimobiledevice/ifuse/issues/63


How to get the full name of the .deb package in command output

Run below command

apt-cache show lighttpd | grep Filename

Output looks like below.

Filename: pool/universe/l/lighttpd/lighttpd_1.4.35-4ubuntu2_amd64.deb

Below command will give u only the deb file name without the path. apt command can be used instead of apt-cache.

apt-cache show lighttpd | grep Filename | rev | cut -d'/' -f 1 | rev

Output:

lighttpd_1.4.35-4ubuntu2_amd64.deb


Is there a text only desktop enviornment for Ubuntu?

? why not better to uninstall all gui environments? then you'll automatically have gui. and my second way is to setup grub to always open recovery mode and not gui (then you have pure cli). and if you want just a really tine environment i found something and that's there : https://reposhub.com/linux/miscellaneous/netxs-group-VTM.html (yes it's in CLI)


GParted stuck, details say resize was successful

Just press the Close button. That's all.


Chromium is corrupted after creating a desktop shortcut

Reading your question I understand that you had synced your account with google?

The simplest (though heavy handed) option will be to just delete your chromium profile. ~/.config/chromium
try mv ~/.config/chromium ~/old-chromium. Now when you start chromium you will begin from a fresh profile where you can add your password and sync it afresh to your data with google.


Follow this installation procedure
sudo apt install mono-runtime yaz zlibc libxml2 libxslt1-dev        # Dependencies
wget "https://marcedit.reeset.net/software/marcedit7/marcedit7.run" # Download MarcEdit 7

chmod u+x marcedit7.run                 # Make it executable
./marcedit7.run --target $HOME/marcedit # Unpackage it on preferred folder

cd $HOME/marcedit
./create_shortcut.sh # Generate shortcut (on ~/.local/share/applications)

Notes

Keep in mind MarcEdit is a non-free software build with C#/Mono and is very buggy under Linux. Either way sadly doesn't exist an open source alternative (so far).
On newer versions (7.3.11) I came across to this issue (Mono 4.6.2, with 6.12.0.122 seems to work). You can report any bugs here.

Why this post: I found this procedure much easier, straightforward and complete way for IT people working on libraries than the instructions of the author. Moreover, this way works and the one shown by the author site doesn't. Doesn't mention chmod the .run file, nor how to generate and move the shortcut to the appropriate location. Also, won't work without fixing the –target to --target, something probably newbies will miss.


Does a user creating text file need to be in a specific place?

You can execute script with ./ if you are in same directory as script.  But if you want to run it from anywhere , you have to put the script into one of the folders listed in your $PATH preferably /usr/bin or add a custom folder to the list.

As for creating a file,  if you specify full path to script , like nano /usr/bin/myscript.sh , yoi don't have to be prese in that directory


Fakeraid in Ubuntu 14.04 wont auto assemble on boot

By trial and error, the following seems to partially work:

Prepend a # to /etc/default/grub.d/dmraid2mdadm.cfg as suggested on ubuntu-devel and bug 1318351
sudo mdadm --assemble --scan
sudo update-initramfs -u -k all
sudo dpkg-reconfigure mdadm

(I'm not sure if step 1 is necessary; I'm also not sure if step 3 is necessary, as step 4 seems to do this anyway)

Before doing this, whenever I rebooted, the file manager would show both disks separately as available to mount. Running sudo mdadm --assemble --scan would replace them with a single merged entry available to mount.

After doing this, whenever I reboot, I see both disks separately as well as the single merged entry available to mount (the merged one has a different icon), and running sudo mdadm --assemble --scan does nothing. So partial success, though I'd still like to know how to hide the unmerged disks.

(another possible solution I haven't tried yet is https://askubuntu.com/a/442788)


Install the Unity Tweak Tool

sudo apt-get update
sudo apt-get install unity-tweak-tool

Open it, click on Fonts and increase the Text scaling factor. You should see the improvement immediately. Explore the other parts of the Unity Tweak tool to further improve your experience.


can't access samba files from specific pc

I think it is more a Windows 10 issue, than a Ubuntu Issue.

It could be configured, that Samba is using the protocol SMB in the version 1.x, but Microsoft knows it is insecure (see things like 'Eternal Blue') and does not support it by default ... But you are able to activate it:
http://wdc.custhelp.com/app/answers/detail/a_id/20736/~/how-to-enable-smb-1.0%2Fcifs-file-sharing-support-on-windows-10

Samba should be able to to negotiate the protocol, so if v1 is not available, it should switch to v2 or v3.


Unable to mount secondary BTRFS filesystem to specific subvolume

Btrfs filesystems do not interact with each other, so you cannot mount the @media subvolume on /dev/sd{b,c}1 because the @media subvolume is currently on /dev/sda1, and you get a cross-device error when you try to snapshot /mnt/media to /mnt/media_snap because /mnt/media is on /dev/sd{b,c}1 whereas /mnt/media_snap is on /dev/sda1.

Instead of having the @media subvolume on the /dev/sda1 btrfs filesystem, you want to create an @media subvolume on the btrfs filesystem on /dev/sd{b,c}1:

sudo mount /dev/sdb1 /mnt/media/
sudo btrfs subvol create /mnt/media/@media
sudo umount /mnt/media/
sudo mount -o subvol=@media /dev/sdb1 /mnt/media/

You can create snapshots of /mnt/media/, but you can place the snapshot only on the /dev/sd{b,c}1 filesystem. So you can create a read-only snapshot like this:

sudo btrfs subvol snap -r /mnt/media/ /mnt/media/<snapshot_name>

But I recommend placing each snapshot of a subvolume outside the subvolume itself, because this simplifies things when you need to revert to a snapshot. To do this, you will need to mount the root of the /dev/sd{b,c}1 filesystem:

sudo mkdir /mnt/media_root/
sudo mount -o subvol=/ /dev/sdb1 /mnt/media_root/
sudo btrfs subvol snap -r /mnt/media_root/@media/ /mnt/media_root/<snapshot_name>


In Evolution, how do I attach my public key to a message?

Evolution does not have a feature for quickly attaching the public key like this. Instead, attaching a public-key is like attaching normal file.

You'll need to locate the public-key in your folder, and attach it to the mail.

Adding Attachments in Evolution

Attaching files

To attach a file to your email in the composer:

  Click Add Attachment…, or click Insert ▸ Attachment, or press Ctrl+M.
  Select the file you want to attach.
  Click OK.

You can also drag a file to the attachment bar of the composer window.

When you send the message, a copy of the attached file goes with it.


Is there any way to set hardware profiles based on where I am at?

Well, you can alter the screen time out in the batter profiles. where i presume you are plugged in to AC power. Or add an inhibitor applet to your panel. when you click on it, the screen will not turn off! =)


How do I set for XTS mode when installing ubuntu with guided setup for encrypted LVM?

The block cipher used by LVM disk encryption is unfortunately not something can be configured during the Ubuntu installer.  Sorry.


Will Windows become corrupted if Ubuntu is dual installed on it

Installing Ubuntu on top of Windows does not corrupt Windows; but yes as Ubuntu uses different file system (ext3 or ext4), this 80 GB partition will not be accessible from Windows.

Later when formatting (if done), change the file system to one recognized by Windows (NTFS or FAT) and free space will be available for Windows.


Is there any command in Linux which does not make a system call?

/bin/true and /bin/false should be the preinstalled commands with the least system calls.

You could save some system calls by static linking:

Save the following as e.g. minimal.c

int main() {
    return 0;
}

and compile it using

gcc --static -o minimal minimal.c

This will get you the program minimal in your current working folder.


I'm not sure how you're getting the windows into different workspaces in the first place, but if you want to put them back, Ctrl-Alt-Shift-Arrow will allow you to move them between workspaces.

For a more permanent solution, if you don't want to use workspaces at all, you can use the compizconfig-settings-manager to disable them. Open the settings manager, select the General Options then Desktop Size tab. Set the horizontal and vertical size to 1 and you will no longer have multiple workspaces.


How to Fix Error ata1.00: failed to enable AA (0x1 = error_mask

Error ata1.00: failed to enable AA (error_mask = 0x1)

This point to a problem with your hardware, be the cables, the hard drive or the motherboard. The only way to fix it, is diagnostic each piece of hardware. Since you said is random, you may test the memory and the Hard Disk first. Ubuntu includes the memtest86+ to do heuristics test to the memory, for the Hard Drive, you should do a full backup of all your important data then replace it.


Can't Login to my Server via SSH, and the password is correct

You need to run ssh (the client, and possibly the server) with more verbosity to understand why authentication is failing.  For the client, run

ssh -vvv username@host

On the server end, check the logs. /var/log/auth.log will give you a pretty good idea about what happens when you try to login, look for messages that contain sshd.  There are a variety of reasons why authentication could be failing, ranging from simple (you aren't using the right username) to more complicated (sshd is configured to use the wrong authentication system).


How do I totally remove grub and install it fresh so it works? (dual boot problem)

Run sudo update-grub on your LiveCD. If that fails, follow the below directions.

For Windows, you will need to manually repair your bootloader.

On the LiveCD, run lsblk.

One of the entries should have lots of sub-entries. It should look something like /dev/sda. Remember what it is!

Then, run sudo grub-install /dev/sda (or whatever it is, you found out above).

Reboot and enjoy.

If you get the infamous cow error message, run these commands:

First off, mount your Linux partition using this command:

 sudo mount /dev/sda1 /mnt #Replace sda1 with appropriate partition

Then, run:

sudo grub-install --root-directory=/mnt /dev/sda


So it took a long time, just because I didn't have time to solve this. I actually just installed Ubuntu again. This time I didn't use the automatic install, instead I choose to create each partition on my own through the installation tool and I created a swap partition. This time the entire process of make the swap work was done by Ubuntu itself and it seems it went well.
I wrote a lot more previously, but my issue was mainly with swap and it seems solved, so I deleted all the other issue I found in the process and I'll open a ticket with them.


Dual Boot System Operating System not Found (Win7/Ubunty 14.04)

I had this problem before. I was not able to get help no matter how much I perused the internet. The only way that I was able to save my data and restore the OS's was to pull the internal hard drive, put it in another computer, and manually pull the important files that I needed. If it is a program that you are trying to save, I have no experience in this. I was trying to save college term papers, projects, and such.


Determine correct CPU core and thread usage

Thankyou for the reminder to check the BIOS Doug! I was sure I had it on there. Nope. So finding Hyper-Threading in the BIOS and enabling it did it!
I ran update -initramfs -u -k all again. Not sure if that was necessary. However, now htop shows all 8 threads working and lscpu reads:
Architecture:        x86_64

CPU op-mode(s):      32-bit, 64-bit

Byte Order:          Little Endian

CPU(s):              8

On-line CPU(s) list: 0-7

Thread(s) per core:  2

Core(s) per socket:  4

Socket(s):           1

NUMA node(s):        1

Vendor ID:           GenuineIntel

CPU family:          6

Model:               42

Model name:          Intel(R) Xeon(R) CPU E31270 @ 3.40GHz

Stepping:            7

CPU MHz:             2659.406

CPU max MHz:         3800.0000

CPU min MHz:         1600.0000

BogoMIPS:            6784.79

Virtualization:      VT-x

L1d cache:           32K

L1i cache:           32K

L2 cache:            256K

L3 cache:            8192K

NUMA node0 CPU(s):   0-7

Thanks so much for the tip to go back into the BIOS. Feeling sheepish that I did not thoroughly go there first, but thanks!


In /dev/input/by-path you should be able to find a link to your keyboard, in my case it's named:pci-0000:00:14.0-usb-0:7.1:1.0-event-kbd.

You can maybe try to $sudo cat /dev/input/by-path/pci-0000:00:14.0-usb-0:7.1:1.0-event-kbd
this can indicate you at least when a key is pressed and released from the "hardware" pov.
In short if it keeps printing while the key is unpressed it means that from the low level pov the keyboard is still sending data. (you can also use files under /sys/kernel/debug/hid/DEVICE/event (device is matching lsusb output))

The strange thing with your problem is that it happens with any keyboard so does not seem to be keyboard hardware related...

Does this problem happen without running Xserver ? Maybe you could also just to see if the problem keeps happening.

Actually to be honest your problem can be related to numerous reasons, I advice you to read this document which will give you some directions to conduct your research.


Is there any (lightspark.so update.alternative) as adobe flash "automatically"?

I don't really understand what the problem/question is, but I think you want to use flash with your Firefox browser.

Try this

sudo apt-get install ubuntu-restricted-extras

and restart your firefox.

Hope this helps ....


The ECMConfig.cmake file is provided in Xenial by the extra-cmake-modules package, so you need to install that - either from your favorite package manager or via the command line

sudo apt install extra-cmake-modules

For errors related to the following message

CMake Error at CMakeLists.txt:27 (find_package):
  Could not find a package configuration file provided by "KF5KCMUtils"
  (requested version 5.16.0) with any of the following names:

    KF5KCMUtilsConfig.cmake
    kf5kcmutils-config.cmake

  Add the installation prefix of "KF5KCMUtils" to CMAKE_PREFIX_PATH or set
  "KF5KCMUtils_DIR" to a directory containing one of the above files.  If
  "KF5KCMUtils" provides a separate development package or SDK, be sure it
  has been installed.

install libkf5kcmutils-dev package.

sudo apt install libkf5kcmutils-dev

You may also need these packages

libkf5kio-dev, libkf5parts-dev, libkf5akonadi-dev, libkf5mime-dev, libkf5akonadinotes-dev, libkf5pimtextedit-dev, libkf5kontactinterface-dev, libgrantlee5-dev packages.


Finding a highly customisable (compose message) email client that works with Exchange 2007!

I have finally found a solution. To be clear this does not solve my problems with Exchange and Evolution but is a workaround that allows me to use Ubuntu Linux with my business email!

Requirements:

Thunderbird
ExQuilla plugin (please not this is now paid for on Thunderbird v24+ since November 1, 2013, at time of licence purchase in 2013, this was US$10)

You then need to edit the msgcompose.text_color in the about:config section.

Many thanks to Sanil Kumar for his solution found here:

  In Mozilla Thunderbird, normally we can change write(compose) window
  Text color by picking color from Text Color window or we can give any
  costume color by putting HTML color code or String name.

  But this color will only effect the current Write window. Next time
  Text color will be the default color. we can set permanent Text Color
  through the Menu Tools->Options.

  Select composition tab from Options Window. Select Text Color in HTML
  option of General Tab. Color which you selected from this option is
  permanently set for all Write window. But unfortunately we can't
  provide custom Color on this option.If you still need to provide a
  Custom Text Color for all Write window then you have to follow these
  steps on your risk.

  Select Options from Tools Menu
  Select General Tab under Advanced Tab of Option Window
  Click Config Editor button
  Click on "I'll be careful, I promise!" in about:config windows warring message to continue
  Type Text and Hit Enter in about:config window Search box
  Double Click on "msgcompose.text_color"
  Enter you Custom Text Color HTML Code in msgcompose.text_color box and Click OK Button
  Close the about:config and Pick a new Write window and Type some text and check your Text Color

  This will set your custom Color as Default Text Color for Write Window

This allows me to receive exchange emails to Ubuntu and customise the email style to fit with my Companies in-house standards. They are now indistinguishable from those I send with (errgh) outlook.


iwlwifi driver missing (Ubuntu 18.04) (Linux Kernel 5.3.0-28-generic)

Got it to work. Booted up an older version of the kernel from grub. Wireless still didn't work but ethernet did. I was then able to redownload ubuntu-desktop.


Winetricks: Can't locate and install d3dcompiler_43.dll?

Get yourself the most recent version of Winetricks as demonstrated here.. After you have done this you will see the required version as I demonstrate below:

andrew@ilium~$ winetricks list-all | grep d3dcompiler
d3dcompiler_43           MS d3dcompiler_43.dll (Microsoft, 2010) [downloadable]
d3dcompiler_47           MS d3dcompiler_47.dll (Microsoft, FIXME) [downloadable]
andrew@ilium~$

And then hopefully all will be well!


how to give user server name instead of ip when connecting through SSH?

You have a few options.

If you need access from only a few locations, or a single location, update /etc/hosts

sudo nano /etc/hosts

Add an entry for your server

66.90.115.178 myubuntu

Second, purchase or find a free DNS service, http://www.noip.com/free/ or similar.

Third, ssh uses your current user name by default, so if you have the same user name on both client and server, just ssh server_name

ssh your_server

You only need to specify a user name if the names are different or you want a new user

ssh new_user@your_server


You can optionally run in the terminal

sudo apt-get update
sudo apt-get upgrade

Watch both those commands and you will find the issue.  Post back and we can debug further.

Optionally once you find the issue you can disable that software source by going into your Update Manager and clicking settings and then going into "Other Sources" if it turns out to be a non-Ubuntu issue and an application installed on Ubuntu like Google Chrome.  My Chrome install uses this URL http://dl.google.com/linux/chrome/deb/


You did provide the username and password, name for your computer, etc. details during the installation, didn't you? The username and password appear to be what you need..

I'm gonna need further info, is this window a terminal (shell, CLI) or a window as in X-Window (GUI)?

P.S. I strongly recommend reinstalling Ubuntu in case the installation was not successful. There may be some important files missing, and given how most of the info is stored as files in Ubuntu, that may pose a big problem to the integrity of your installation..


Installing libgtk-x11-2.0.so.0 in Ubuntu 15.04

At least in Ubuntu 16.04, libgtk2.0-0 contains libgtk-x11-2.0.so.0, so this works:

apt-get install libgtk2.0-0


How to configure tftpd-hpa to allow upload of new files?

From tftpd's manpage:

--create, -c
      Allow new files to be created.   By  default,  tftpd  will  only
      allow  upload  of  files  that already exist.  Files are created
      with default permissions allowing anyone to read or write  them,
      unless the --permissive or --umask options are specified.

Change server_args to:

server_args             = -c -v -s /var/lib/tftpboot

You don't need xinetd to get tftpd up and running. This is how I install and configure tftpd:

sudo aptitude install tftpd-hpa
sudo chown -R tftp /var/lib/tftpboot

Edit /etc/default/tftpd-hpa to insert -c into TFTP_OPTIONS. The line should look like:

TFTP_OPTIONS="--secure -c"

Finally, restart tftpd service:

sudo service tftpd-hpa restart


Ubuntu 16.04 - Black terminal, weird colors, lacking graphical info after installing Evolution

What ended up working
Instead of going back to a stable state by hand, I ended up relying on dist-upgrade solve my broken system. As noted here it might be safer to do this in recovery mode:
sudo dpkg --configure -a
sudo apt-get update
sudo apt-get -f install
sudo apt-get -m install
sudo apt-get dist-upgrade
sudo apt-get install --reinstall ubuntu-desktop
sudo apt-get autoremove --purge
sudo apt-get clean

Rebooting then reinstalling the nvidia drivers (the actual version needed for your system might be different, can be checked here and here):
sudo apt-get purge nvidia-*
sudo apt-get install nvidia-396

Reboot one last time and hopefully things should be ok.


Upgrade from 14.04 to 16.04 LTS failed with a kernel panic

I had similar issues, now the machine started to work if I select the "systemd" boot option.


lubuntu, make the terminals / some windows, to not stack in the task bar

Sure, you can show the terminals individually on the task bar.

Right-click the task bar area
Select Task Bar/ Window List Settings
Uncheck the "Combine multiple application windows into a single
button" setting

Mine looks like this (using Numix Circle icons) when I have 2 terminal windows open.

I have "icons only" checked, if you want the descriptive text, uncheck that.


.whl is not a supported wheel on this platform

Tensorflow doesn't support x32 bit system, only x64 bit system, and my ubuntu was x32 bit, and there fore I wasn't able to install. There is some dirty hacks that with them works, but I decided to go further in ubuntu with x64 bit system.


I can not get ubuntu to completely down load, any suggestions

Ubuntu is free. I think you missed the "Not now" button located bottom left corner of the Donation page.

If your internet connection is slow, download it using torrent. Here is the torrent file: http://releases.ubuntu.com/xenial/ubuntu-16.04.2-desktop-amd64.iso.torrent


Can't change destination of symbolic link

To create a symbolic link to a directory, use the 'n' option:

ln -sfn DESTINATION_DIRECTORY LINK_NAME

DESTINATION_DIRECTORY is the name of the link target;
LINK_NAME is the name of the link.
The f option means to replace the existing link (ie, delete it first).

The n option is a bit complicated.  I believe your command may have created a link to jdk1.7.0_07 inside  the directory jdk1.7.0_04, via the link oracle-jdk-7 rather than replacing the link. If so, you should delete the link to avoid confusion.


How to archive with ignoring files larger than 100MB

Yeah there are probably a few more ways of doing this but you're probably best off with find as it's so tunable.

find /path/to/dir -size -100M | xargs tar cvf archive.tar

or

tar cvf archive.tar $(find /path/to/dir -size -100M)

If there are other directories in the current folder which you do not want to archive, then use:

find /path/to/dir -maxdepth 1 -size -100M | xargs tar cvf archive.tar

Per the comments below, spaces can throw out some errors but in my testing they still seemed to get added to the archive when using the first method (a little strange in itself) but if you're worried, you can fix the find command to replace spaces with escaped versions.

As ever, there are a billion ways of doing this.

find /path/ -size -100M | sed 's/ /\\ /g' | xargs tar cvf archive.tar

find /path/ -size -100M -exec echo '"{}"' \; | xargs tar cvf archive.tar


Ubuntu 14.04 audio not heard(dummy output)

There is a basic sound troubleshooting guide here.

To reinstall back to the official drivers open a terminal and type

sudo aptitude --purge reinstall linux-sound-base alsa-base alsa-utils linux-image-`uname -r` linux-ubuntu-modules-`uname -r` libasound2

then update the system:

sudo apt-get update

Please try trouble shooting first.


How to lower refresh rate on external display (projector) from 75 hz to 60 hz

Is there a setting for the display in the GUI Settings / Display? There should be (at least used to be) options to change the refresh there.

Or in a terminal using xrandr -r 60 should work (might need to use --output ... (maybe --output HDMI-0?) or --screen ... before. Try just xrandr to see what it tells you are available modes & info.


Help with migrating from Widows, x64 FGLRX, CPU load, Java and Minecraft

Run ps -ef > before then ps -ef > whilst while it runs and then ps -ef > after after closing. Finally upload the files
before whilst after


Is dual booting ubuntu and fedora/openSUSE as easy as popping in a liveCD?

You can install each system separately, by booting from their respective live/install CD's and running their installers. Whatever order you install them in, each has the ability to resize partitions created by the others to make room for itself. Alternatively you could partition manually so that dynamic partition resizing is not necessary (making sure that each OS's partitions take up little enough space that there's enough unpartitioned space left over for the subsequent OSes). Another benefit to partitioning manually is that you can make them all use the same swap partition, which would probably not happen if you installed without manual partitioning. (On the other hand, if you want to be able to hibernate one OS and boot into another, then they must have separate swap partitions.)


Ubuntu Terminal server for Windows clients

There are many options. You can use xrdp for this, which would be available to the built-in rdp-client in Windows. An easier solution, that also probably provides a better experience, is X2go. However, this requires an application to be installed on the client. There's also Nomachine NX, which is the upstream for X2go.


Where does bash take its PATH from if run with --norc option?

It's hard-coded in the bash source code, and is unrelated to any Ubuntu-specific patches. Namely, it's located in config-top.h in the root of the bash source tree:

/* The default value of the PATH variable. */
#ifndef DEFAULT_PATH_VALUE
#define DEFAULT_PATH_VALUE \
  "/usr/local/bin:/usr/local/sbin:/usr/bin:/usr/sbin:/bin:/sbin:."
#endif


How to force Skype's Panel icon to show Skype's main window in workspace 4 specifically?

You could use devilspie to make all subwindows open in a particular workspace. This is a relatively easy application to use. As for the second half of the question, I don't have an answer.

sudo apt-get install devilspie


Check out the answer here: https://askubuntu.com/a/141536/38557.  It's a bit long but should do exactly what you're trying to achieve.


Ubuntu 18.04 server on VPS. How to make .iso backup

Well my personal opinion is that backing up an entire vps just for a webapp is a waste of time. Let's say you want to do that, you will need the same amount of free space as your vps drive then use a command like dd to copy an exact image of the drive, if you try to do this on the actual vps you'll run out of space.
scenario 2: Backup only relevant data and programs, copy your programs folders in /etc/ and /var/lib whatever and then recover if something happens.
Scenario 3: use docker for your webapp, that way you can install whatever you need freeze the image only backup the image and whenever you need to replicate just load it and in matters of minutes you will have your service up and running again.


How to solve this problem (404 Not Found) while updating

If you look at http://ppa.launchpad.net/tahutek-team/prozilla/ubuntu/dists/, you will see that they are not mirroring the wily distribution.

I'm not sure why your sources are set to point there though. You might want to either contact the mirror owner (https://launchpad.net/~tahutek-team), or update your sources.list file (found at /etc/apt/sources.list) to point to a valid wily repository.

You can use the instructions at How do I restore the default repositories? to reset your repositories to the default.


Unity Panel (Unity is new interface for Ubuntu 11.04 with new top panel) doesn't support applets for GNOME Panel.
You can use Hamster Indicator (package hamster-indicator) from Alberto Milone's PPA repository
ppa:albertomilone/hamster-indicator
More information here:

http://www.webupd8.org/2011/07/install-hamster-indicator-time-tracking.html

http://albertomilone.com/wordpress/?p=502

There is a lot of indicators, many of them have same funtionality as applets for GNOME Panel in ubuntu 10.10 and older.
List of indicators -- What Application Indicators are available?
If you want to add a indicator to the Unity Panel, you have to install it and then run as a normal applications (from menu or via terminal), you can't add it using right click on panel.


How to update single application like VLC only?

sudo apt-get install vlc will install OR upgrade vlc


Ubuntu changes drive order with multiple HDDs

The drive are named (sda, b, ...) in the order they are ready for the system I think and it changes, mainly if you have usb ones. Anyways, if you mount them using UUID instead of sda, sdb, you will have no more problems as UUID are fixed.


How to copy files from usb to ubuntu server 12.04

you have to use cp with sudo since /var/www have  permissions:

sudo cp /media/your-usb/whatever /var/www/

For example lets say your usb is mounted under /media/usb and you want to copy file named file.txt to /var/www

sudo cp /media/usb/file.txt /var/www/

Take a look for these:

https://help.ubuntu.com/community/FilePermissions


How to change my account type from standard to administrator?

Boot into recovery modus. There you have superuser rights to change it back.

adduser Yngthlet admin

Exit and proceed.


Ubuntu 20.04 LTS Fractional Scaling not Working (Intel GPU)

Fixed it.  The gsettings must have been messing with the GUI.

Once I cleared the gsettings, rebooted, I had the scaling options.

TL/DR: Don't use gsettings to change the fractional scaling on Ubuntu 20.04.


Undefined Symbol Error when running SDL program

Still not sure why this was happening with SDL1.2, but I suspect it's probably related to the below:

I removed SDL1.2 and downloaded SDL2 instead. It turns out that a 2012 update to X11 added a dynamic symbol for _XGetRequest, which is what was causing my problem in SDL2. To fix the issue, I downloaded and installed SDL2 from the official Mercurial repository, rather than from the Ubuntu package manager.


Is there any way to make the Alt-Tab window changer pop up quicker in Gnome-Shell?

Well, you can change that in the .js file of the alt-tab.

In

/usr/share/gnome-shell/js/ui/altTab.js

Almost at the beginning of the file, is this line

const POPUP_DELAY_TIMEOUT = 150; // milliseconds

Change it, save and restart the gnome-shell (Alt+F2 type 'r', or logout and login again).


Unable to get TRIM to work on Ubuntu 12.10

You appear to be trying to trim /mnt is something mounted as /mnt ? usually people use /mnt/myPartationName most likely defined in /etc/fstab
If you are only using a single partition and you are running on a SSD change this:
SSD_MOUNT_POINTS='/mnt'
to this:
SSD_MOUNT_POINTS='/'
If that is the case you could just put fstrim / as your cron job instead of
that entire script like this
#!/bin/sh
fstrim /
Here is a SSD guide: https://sites.google.com/site/easylinuxtipsproject/ssd


The method to backup your sources list has already been described by garbagecollector (also note the additional directory as explained by Javier Rivera).

To backup the trusted keys added to your system you can use the apt-key command line program. I don't know if there is a way to do this from the GUI.

From a terminal you can run something like this:

sudo apt-key exportall > ~/repositories.key

Then on your other system you should be able to import that key file from Software Sources or you can use apt-key again:

sudo apt-key add /path/to/repositories.key

I only have one Ubuntu desktop system so I haven't tested this out, but I think it should work.


GDAL install failing on Ubuntu 16.04 LTS

I found that there was a bug in 2.0.0, and that I needed to install 2.1.0.  I just swapped the version numbers and it works great!


Boot from CD or USB stick, before the OS starts (as soon as you see the small keyboard icon to the bottom) press any key.

You'll end up in a boot menu. Select your language if you are asked, then press F6 and select "nomodeset", press ESC and run the live cd by selecting "Try Ubuntu"

If it doesn't work try by adding the nomodeset option manually to the boot options string that will appear as soon as you press F6


how to delete temp files which is created by google chrome in linux?

Normally Google Chrome save this temporary files inside:

~/.cache/google-chrome/[profile]/Cache/

and

~/.config/google-chrome/[profile]/Application Cache/Cache/

And yes you can delete these manually and you don't need any permission.

So just take a look at these dirs and choose what to delete

Another interesting directory is

~/.config/google-chrome/Default

Here you find your history , bookmarks , extensions, ....

so choose carefuly what do you want to purge

UPDATE:

The bookmark is not really a directory it's just a file. The path to this file is:

~/.config/google-chrome/Default/Bookmarks

The history also is not a file, it's some sqlite3 database file under this path

~/.config/google-chrome/Default/History

A simple tip:

nautilus ~/.config/google-chrome/Default

will open the directory so just take some time and check all of files found there, you can easily know what to keep or what to delete


Use chown to change the owner:

sudo chown root:root /usr/lib

This will change the owner of /usr/lib directory to root.


No icons for automounted volumes on GNOME / Nautilius desktop on Ubuntu 19.04

The mechanism by which desktop icons has fundamentally changed since Ubuntu 19.04. Previously, desktop icons were provided by the file manager Nautilus. That functionality was stripped out of more recent versions of Nautilus. Because of this, Ubuntu shipped with an older version of Nautilus.

In Ubuntu 19.04, nautilus ships with an up to date version of Nautilus, which cannot provide desktop icons. To implement desktop icons, they now make use of a GNOME Shell extension "Desktop Icons". This extension can still be called "early" and does not support all features of the old system. Among others, icons for removable icons will not automatically be placed and removed from your desktop.

Until the "Desktop Icons" can bring back that feature, you will need to change your workflow.

Removable icons are visible in the left pane of the file manager. They can easily be managed there.
Alternatively, you could install a GNOME Shell extension "Removable drive menu". This adds a button on your top bar from which you can access removable drives. This button is always visible, in contrast to a desktop icon, which is more often hidden by an application window than not.

The GNOME Shell extension "Removable Drive Menu" is an officially supported extension because it is part of "GNOME Classic", a series of extensions that make GNOME Shell look and (more or less) behave as GNOME 2.

You can install it (along with some other of this group of extensions) by installing the package gnome-shell-extensions. You will need to install "GNOME Tweaks" to activate the extension.

Alternatively, you can install it from the GNOME Shell extensions website.


I reverted back to 18.04LTS which fixed this issue.
not sure why 19.04 did, but it had some other weird issues as well on my computer.


Since Boot Repair is failing, I recommend you try the following:

If you haven't already done so, disable Secure Boot.
Download the USB flash drive or CD-R image of my rEFInd boot manager.
Prepare a boot medium from the files you've just downloaded.
Boot using the rEFInd boot medium. It should present options to boot both Windows and Ubuntu.
Test your boot images. If you can boot Ubuntu, and ideally both OSes, proceed....
Boot Ubuntu.
Install a boot manager/boot loader:

If you're satisfied with rEFInd, you can install it to your hard disk via the PPA or Debian package, as described on its downloads page.
If you prefer GRUB, you can try to fix its installation manually. This will require some expertise, but it should be possible to do. Unfortunately, it's not clear to me what's going wrong, so I can't offer any specific suggestions.
You could also install any of a number of other EFI boot loaders for Linux, as I summarize on this page.

If you want to use GRUB and need more help, post the URL that Boot Repair provides. That points to system-specific diagnostic information that might provide some clue about what's going wrong. Without such information, any GRUB-repair suggestion will be a shot in the dark.


The message Fixing libtool for -rpath problems. isn't an error.

The easiest thing to do is to install bitcoin via a PPA:

sudo apt-add-repository ppa:bitcoin/bitcoin
sudo apt-get update
sudo apt-get install bitcoin

The correct way of what you're trying to do, is:

Simply run make.

And here is the part in configure

dnl Taken from https://wiki.debian.org/RpathIssue
case $host in
   *-*-linux-gnu)
   AC_MSG_RESULT([Fixing libtool for -rpath problems.])
   sed < libtool > libtool-2 \
 's/^hardcode_libdir_flag_spec.*$'/'hardcode_libdir_flag_spec=" -D__LIBTOOL_IS_A_FOOL__ "/'
   mv libtool-2 libtool
   chmod 755 libtool
 ;;
esac


Black toolbar icons error o LibreOffice 5.1

Turning Jim K's comment into an answer:

  Under Tools -> Options -> LibreOffice -> View, what is the Icon Style setting? For example on mine it is "Automatic (Tango)." Also what is the theme setting in Tools -> Options -> LibreOffice -> Personalization?


Laptop with Ubuntu not turning on after mok managment screen appeared

MOK Management is a feature of Secure Boot. Please turn off Secure Boot in your BiOS.


Ubuntu 18.04 is not booting after uninstalling Windows 10 from dual boot

Modern PCs have 2 boot options, UEFI or Legacy. You likely installed Ubuntu in UEFI mode and have deleted the EFI partition. This means now Ubuntu can't boot.

Sounds like you need to rebuild the EFI partition.
https://help.ubuntu.com/community/UEFI

Your data is still there, but you just can't load it. The partition has a boot flag. Likely, you Ubuntu partition does not.

Take a look at this section of the article referenced above.
Creating an EFI System Partition

Each install is different, so I don't have an exact answer, but I bet you just need a new EFI partition with appropriate flags and repaired to contain the correct EFI files.

Also, see here:
Converting Ubuntu into UEFI mode


Difference between packages bcmwl-kernel-source and broadcom-sta-dkms?

According to the Community Wiki for the Broadcom drivers states the following:

  The propietary Broadcom STA Wireless driver is maintained upstream by
  Broadcom. As this driver is closed source, fixes in the driver itself
  may only be provided by Broadcom. As a convenience, Ubuntu offers two
  versions of this driver:

  The bcmwl-kernel-source package aims to offer a later version for a
  given release. Instructions for installation may be found later in
  this article.
  The broadcom-sta package aims to offer an earlier version for a given
  release. For further installation instructions, please see here.

The link above takes you to https://wiki.debian.org/wl which shows the compatible chipsets that the broadcom-sta driver support and installation instructions.

Hope this helps!


msi gs70 ubuntu 13.10 stuck on boot, loading initial ramdisk

I am having a similar issue. I have Ubuntu 13.10 dual booting with Win 8. Both OS were working fine until today when I got a blank screen trying to boot into Ubuntu from the GRUB menu. When I tried to boot via advanced options and in recovery mode I noticed it stuck on "Loading initial ramdisk". I have not been able to fix it yet since I am at a hotel and do not have my liveUSB.

The only thing that I can think of that changed on my system between the last time I logged into Ubuntu successfully and today was a windows 8 update. I foolishly never changed it from automatic updates so I have no idea what it installed. Is it possible that the windows updated somehow effected GRUB? It sounds like this is a graphics driver issue, so I am not sure how a windows update would have been to blame.


My laptop toshiba satellite p75-A7100 pad right-click is working as a left-click?

Open settings, click on Devices and open the Mouse & Touchpad tab.
You will get a window similar to the one above.
Change the Primary Button to Left.


Error when trying sudo apt upgrade or install

This problem occurs when packages are broken or not fully upgrade.

sudo rm /var/lib/dpkg/info/*
sudo apt update
sudo apt autoremove
sudo apt autoclean
sudo apt install -f
sudo dpkg configure-a

Try the commands above.


Problems using dual monitors via Optimus and HDMI

On Ubuntu 14.04, I could fix that issue by changing the display settings on Compiz. Have a look at 14.10 Dual Monitors are displayed as distorted single screen mode

On CompizConfig Settings Manager, go to "General Options", then "Display Settings" and do the following:

Uncheck Detect Outputs
In the Outputs array, set the resolutions of each of your screens. The numbers after the resolution 1920x1080+0+0 are the offset. It's important to add this offset according to your needs. I have two full HD screens, so I added the following configuration:

1920x1080+0+0
1920x1080+1920+0

The second output has an offset of 1920, because it is on the right side of the first output, which has a width of 1920.


First of all it is crucial that you do not write anything on the memory card until you recovered the deleted images.

Your best bet is PhotoRec. It is part of the testdisk package. Install it with

sudo apt-get install testdisk

Then run photorec as super user

sudo photorec

You'll be presented with the list of connected devices, including your hard drives. Select the memory card (it will probably be something like /dev/sdb or /dev/sdc but check it carefully). Follow the on screen instructions.

Another alternative is recoverjpeg that is specifically tailored for JPEG recovery.

Install it with:

sudo apt-get install recoverjpeg

Open "Disks" (you find it in your applications). You'll find the list of connected devices. Select the memory card. On the right hand you'll find the details of the device included where it is mapped (eg: /deb/sdb1)

Then you can try with recoverjpeg like so:

sudo recoverjpeg /dev/sdb1

IMPORTANT: replace sdb1 with your actual device!

You'll find the recovered pictures in your home directory.

Also have a look at this https://help.ubuntu.com/community/DataRecovery


Xubuntu 18.04 - Whisker menu and xfce4-indicator-plugin in xfce4-panel, don't match Gtk theme Configuration

Global themes are in /usr/share/themes/, and should be overridden by the local themes in ~/.themes.

It appears that Snap apps have their own themes, e.g. /snap/whatsdesk/17/usr/share/themes/Raleigh

Parasite should at least be able to source the GTK style of the former.


Unable to shrink Ubuntu partition because it's full (when it actually isn't)

Unfortunately, you are using LVM, so this is not just as simple as resizing a partition in gparted.

What you are seeing in gparted is not a plain partition but an LVM physical volume.  This is an area of space on the disk reserved for LVM to put its logical volumes.  Then, inside those logical volumes are the partitions your system uses.  However, gparted doesn't see these, it just sees one big physical volume which it doesn't know how to edit or move.  Instead, you use the LVM tools to see and manage the logical volumes inside.

The good news is that you can resize and physically move around your logical volumes quite easily using LVM and you can even do this while the system is running.  The bad news is that actually moving or resizing the LVM physical volume around them is quite difficult.

The "LVM way" of doing this would be to set up a new physical volume on a new drive, add it to the same volume group, then live migrate the logical volume to the other drive.  Then, with the physical volume on the original drive now unused, you can remove it from the volume group, and then you can trash that physical volume and re-create it.  The reason I call this the "LVM way" of doing it is that it ensures zero downtime - it can be done on a live system, especially if it has the ability to hotswap in a new drive.  Of course, the downside of doing all this is that it's really slow to migrate all that to a second drive, and that it requires a second drive, so the main benefit is only to people who want to do it on a live system without shutting down.

That said, if you are confident with messing with the partition table yourself, you can take a short-cut, with the help from the pvresize tool which can resize an LVM physical volume (but only if you also change its size in the partition table manually).  It's not an easy process.  You'll first need to shrink the filesystem in the logical volume, then shrink its logical volume to match, and migrate the remaining extent so that the free space in the volume group is all at the end of that physical volume if necessary.  The included LVM tools will help this far.  Then, work out how much you can shrink the physical volume, change its size in the partition table and simultaneously update its size in LVM with pvresize.

The exact procedure is detailed here:

https://serverfault.com/a/419279

If you do go this route, I'd recommend a backup because it will be very easy to screw up and lose data.  And if you're doing a backup anyway, you may as well just do things the old fashioned way and copy everything off the drive, delete the partition and start again, then copy everything back instead.

It's reasons like this I don't recommend LVM for anyone, unless they know they need it and can deal with this stuff.  If you don't absolutely need to be able to hotswap in a new drive, migrate one or more partitions to it, deactivate and remove the old drive, all on a live system without shutting down or rebooting, then (in my opinion) LVM is not really relevant to your needs, and the old fashioned way (plain partitions) will be easier, due to fewer levels of abstraction (easier to get your head around) and tools like gparted which can easily modify and resize them.


Ubuntu MATE 16.04.02 - Updates 5/10/2017 Corrupted Thunderbird fonts (Sidebar only)

Yep, I'm having the same problem. I have my appearance set as Mattinee, a dark theme, but now the messages panel in Thunderbird is a light theme. These problems came with the update to 52.1.1.


Linux stops responding when too much memory is consumed by running programs

The solution for my problem is described here as pointed out by @guiverc. Indeed, the swap was off (top -h gave all zeros). I has re-created it following the detailed instructions outlined in @heynnema 's answer and it is working as expected after reboot. I have not experienced any RAM-related problems since then.
The credit for resolving the issue goes entirely to @heynnema and @guiverc.


How to get audible feedback ("Thunk" sound, no typewriter) when pressing a keyboard key?

In Ubuntu 17.04 (or newer, I suppose) one can install with sudo apt-get install bucklespring, which will do what I think you want. Once installed, it can be started by simply executing buckle and stopped by Ctrl+C.

If you're on an older Ubuntu, you can try to install bucklespring from this PPA: https://launchpad.net/~mirabilos/+archive/ubuntu/ppa .

If the default sound recordings of IBM Model M are not suitable, you can replace them with your own. You can have a different sound for each key, but assuming you have only one sound, you need to make a few links to it, so that bucklespring will use it correctly. Assuming your sound file is called sound.wav:

cp -av /usr/share/buckle/wav my-sounds
cd my-sounds
for fname in ??-?.wav ; do ln -sfv ../sound.wav "${fname}" ; done
cd ..
buckle -p my-sounds

(If the delay between the keypress and the sound is too long for your needs, bucklespring seems to support jack, which supposedly introduces less latencies.)


How do I get mrbs installed and working?

Apparently what I want is called a LAMP server.
According to the Here all I need to do is

 sudo apt-get install lamp-server^

with the ^ or else it doesn't work. Anyhow I've done this and I no longer get a blank page now I get a "Fatal error: failed to connect to database"

Turns out, I had tried to give my mrbs mysql user enough privileges, but it didn't go right. Fixed this and it works!


How do I get rid of my current branch, and pull in the latest revision from trunk in Bazaar?

Using

bzr shelve
bzr uncommit
bzr pull --overwrite

--overwrite
    Ignore differences between branches and overwrite unconditionally