how to change session when on MacBuntu theme?

What about:

gnome-session --session=xmonad

Also consider looking at man gnome-session

From:
How do I change the default session for when using auto-logins?

  i.e.

  sudo nano /etc/lightdm/lightdm.conf

  change the line

  user-session=ubuntu

But in this case you would change the line that says user-session to: user-session=xmonad

Similar questions:

Add a new custom session?
How do I make a program auto-start every time I log in?
How do I replace the desktop by an application?


Startup Disk Creator fails to format USB drive

The Startup Disk Creator tool is known to having some issues to create the USB properly.
Instead use the Disks tool (gnome-disk-utility) to create the Ubuntu installation media.

Open Disks and select Restore Disk Image from the menu on the top right of the application.
Choose the Ubuntu installation ISO file and the USB drive to write it to and then start restoring.


That's a hardware failure. There is nothing on the software side you can do.

I have a thumb drive which once behaved like this. I was able to make it work, again, by opening it, taking the 2 parts it consisted of apart, and sticking them back together, again. It still had its data on it but I nuked it, just to be sure it's not corrupted. That is, I created a new partition table and a new partition in it. But you could also copy the existing data back onto a more stable drive if you need it (and just hope it's not corrupted).

That is of course not to say it will work for your thumb drive. Furthermore, I wouldn't exactly rely on a drive which failed in the past to work in the future.


How can I get SD cards to mount automatically even when X isn’t running?

You will want to install and set up udisks.

They should then be accessible in /mnt/media/, named by their UUID.

You can see the UUID's of the currently-connected devices by running sudo blkid or ls /dev/disk/by-uuid/.


Ubuntu 12.04 suddenly cannot connect to WPA2/WPA Personal protected connection. Windows 7 can

Did you change any settings on the router?

It might be that the operating system has still saved some preferences like another form of encryption or so. If that is the problem you should be able to solve it by deleting and readding the network to your connection list.


How can I set the live stream from ISS HD Earth View as my desktop background?

Installation

Install vlc :
sudo apt-get install vlc

Install livestreamer :
sudo apt-get install livestreamer

Install python-librtmp :
sudo apt-get install python-librtmp

High Definition Earth Viewing System (720p)
HD stream
This command displays High Definition Earth-Viewing System (HDEV) on wallpaper mode, full screen, with no window decoration and no audio.
livestreamer http://ustream.tv/channel/iss-hdev-payload best --player 'vlc -I dummy --video-wallpaper --no-video-title-show --noaudio'

HD stream (720p) with Audio (crew/mission control conversations)
This command displays the HDEV and add sound from another stream, Live ISS, accompanied by audio of conversations between the crew and Mission Control.
livestreamer http://www.ustream.tv/embed/9408562?html5ui best --player "cvlc --no-video" & livestreamer http://ustream.tv/channel/iss-hdev-payload best --player 'vlc -I dummy --video-wallpaper --no-video-title-show

Live ISS Stream (480p)
Display the ISS Live stream (different viewpoint, on air more often)
SD stream
livestreamer http://ustream.tv/channel/iss-hdev-payload best --player 'vlc -I dummy --video-wallpaper --no-video-title-show'

SD stream with Audio (crew/mission control conversations)
livestreamer http://ustream.tv/channel/iss-hdev-payload best --player 'vlc -I dummy --video-wallpaper --no-video-title-show --noaudio'

Bash ON/ OFF script
A simple script iss-background.sh for turning on and off the background.
#!/bin/bash
PS=`ps -ef`
if echo "$PS"|grep -q 'vlc -I dummy';
    then echo "off";
    kill $(ps aux | grep 'vlc -I dummy' | awk '{print $2}')
else echo "on";
    livestreamer http://www.ustream.tv/embed/9408562?html5ui best --player "cvlc --no-video" & livestreamer http://ustream.tv/channel/iss-hdev-payload best --player 'vlc -I dummy --video-wallpaper --no-video-title-show --noaudio'
fi

Improved bash script
Just select the path of an icon you want to be displayed with notifications, or delete the third line Icon="/path/to/nasa_icon.png the two -i $Icon options)
#!/bin/bash
PS=`ps -ef`
Icon="/path/to/nasa_icon.png"

if echo "$PS"|grep -q 'vlc -I dummy';
    then notify-send -i $Icon "  ISS background OFF" \ "\"Houston, We've Got a Problem !\"";
    kill $(ps aux | grep 'vlc -I dummy' | awk '{print $2}')
else notify-send -i $Icon " ISS background ON" \ "Dowloading data from ISS...";
    livestreamer http://www.ustream.tv/embed/9408562?html5ui best --player "cvlc --no-video" & livestreamer http://ustream.tv/channel/iss-hdev-payload best --player 'vlc -I dummy --video-wallpaper --no-video-title-show --noaudio'
fi

Associate it with a launcher:
Just replace the following lines : Icon= , Exec=, and Path=,
[Desktop Entry]
Version=1.0
Type=Application
Name=ISS
Comment=Display ISS live stream as background
Icon=/PATH/TO/YOUR/icon.png
Exec=bash iss-background.sh
Path=/PATH/TO/YOUR/SCRIPT/
NoDisplay=false
StartupNotify=false
Terminal=false

Troubleshooting :

Black screen : International Space Station (ISS) is on the night side of the Earth.
Unity launcher is hidden : I can't figure out a way to do it otherwise.

If one of the following occurs :

Blue screen
No video
error: No streams found on this URL

it might be that :

"The space station is experiencing a temporary loss of signal"

And you might want to check with your web browser if the videos are on air HDEV and Live ISS.


I solved this by changing to the closed source FLGRX driver.


vmlinuz and initrd strange files appeared in "/" directory

Well, they are symbolic links and, as muru said, probably they have been there all the time but you just didn't notice them.

This answer in Ubuntu Forums explains pretty well why they're there:

  Let's look at a grub config entry in /boot/grub/grub.cfg:

menuentry 'Ubuntu' --class ubuntu --class gnu-linux --class gnu --class os $menu
entry_id_option 'gnulinux-simple-blahblahblah' {
        [...]
        linux   /boot/vmlinuz-3.16.0-28-generic.efi.signed root=UUID=blahblahblah ro  quiet splash $vt_handoff
        initrd  /boot/initrd.img-3.16.0-28-generic
}

  You don't need those symlinks if you always boot from this grub.cfg.
  If you are ever manually pointing grub to a boot, 'vmlinuz' is a lot
  easier to remember and type than '/boot/vmlinuz-3.16.0-28-generic' The
  symlinks are a legacy from simpler booting times, but still
  occasionally very handy.   You can delete the symlinks if you wish,
  but they will be recreated the next time grub updates it's grub.cfg
  file.

  Lots of stuff gets updated automatically whenever you install a new
  kernel, including your initrd.img and grub.cfg...and those symlinks.

More info about vmlinuz and initrd.


why scp foo.txt root@remoteMaching: fails

Probably because of #PermitRootLogin prohibit-password (or similar) in your /etc/ssh/sshd_config. Uncomment this line, change it to PermitRootLogin yes and reload sshd. Please note, that this is not recommended!


Realtek 8812AU / 8821AU wireless driver for Ubuntu 20.10

Found this thread early, then tried 2 hours of repositories to get a working driver.  8812bu - different chipset
The morrownr github repository works on 20.10 - 19 May 2021
(it also works on rtl88xxxu chipsets from documentation)
Install commands:
sudo apt update
sudo install -y dkms git
sudo apt install -y dkms git
mkdir src
cd src
git clone https://github.com/morrownr/88x2bu.git
cd 88x2bu/
sudo ./install-driver.sh

lsusb:
Bus 001 Device 002: ID 0bda:b812 Realtek Semiconductor Corp. RTL88x2bu [AC1200 Techkey]
uname-a:
Linux  5.8.0-53-generic #60-Ubuntu SMP Thu May 6 07:46:32 UTC 2021 x86_64 x86_64 x86_64 GNU/Linux


its either DVD drive or HDD is not working properly

check all the cords connecting those chups + check S.M.A.R.T.


Deja-dup intentionally is designed to be very simple, allowing the user to create a reliable backup without hiss. It therefore does not, and will not, feature an option to have multiple destinations.

You may use the command line tool duplicity to do backups in different locations. Duplicity is the backend used by Deja-dup, and accordingly makes a similar type of backups.


Sound completely cut out, and Restart or Pulse Audio can't fix it

Run alsamixer in a terminal, and then ensure that PCM is not muted:

You may also need to check the volume of other settings depending on your sound card. To ensure you only do this for outputs, press F3, then raise the volume of each one using your arrow keys to select or raise the volume.
Your update gave me the answer.
Using alsamixer, look for the headphone jack sense option and ensure that it is unmuted. If muted, it will be marked "MM"


Why can my System (Dell Inspiron N4050) not connect to my WiFi any more? (12.04)

I had the same problem. After some effortless research, I decided to remove the proprietary driver, and after a reboot, the connection could be established once again. (I think we have to wait for a driver update from Broadcomm.)


Ekiga isn't a client as such, but a provider. Think of them as the sip equivalent of Gmail.  I think that any sip call has to go via a provider.   So you want to find a provider that supports ipv6. I would guess that most of them do. These would all be paid services, but for calls to sip addresses with the same domain you might not have to pay anything.


Try regenerate icon cache for all themes

sudo find /usr/share/icons/* -maxdepth 0 -type d -exec echo -e "\n"{} \; -exec gtk-update-icon-cache -f {} \;

Cache file created successfully. ie OK

No theme index file. ie it wasn't a theme folder. Only if you think otherwise, so index.theme is missing.

The generated cache was invalid. ie there is a problem.
Not solved, Try reset theme preferences to defaults:

dconf reset -f /org/gnome/desktop/interface/
dconf reset /org/gnome/desktop/wm/preferences/theme

References:

CPU Scaling in Unity with indicator-cpufreq
man gtk-update-icon-cache


The easiest wil be to find Additional Drivers application amd hope that Ubuntu picked up your video card's native driver. Install it if it's there.


Bluetooth mouse does not work in Ubuntu 14.04

I was having the same problem. I found a solution that works for the 14.04 Ubuntu on my MacMini listed underneath related over in the right hand margin of the "Questions" page. I mated my mouse with a different computer, then thru the command key tap, in the next window arrow down until you get to the tool bar at the bottom of the window, Right arrow to the Apps Icon, "Enter" to select, on the next page manuever to the bluetooth icon, in the next window "Tab" until you highlight the "+" button, hit "Enter", turn your mouse on and its at this point my Logitech Travel mouse was recognized. Follow the prompts from there. Good luck.


NTFS support in Ubuntu is excellent until something goes wrong; because NTFS is basically a Windows filesystem, many of the tools assume a Windows system is available.  It may not be possible to fix it without a Windows system to check from, but according to the first answer to this question it's possible to download a Windows recovery CD that would allow running chkdsk.

It is also worth examining the various ntfs tools installed by default, especially ntfsls and ntfscat.  These allow one to manually access files without mounting the filesystem, but for thousands of files it's naturally not very practical, and as such should be considered a last resort.

The best solution, in terms of the simplest one with a good chance of success, remains gaining access to a computer with Windows, connecting the hard drive, and running chkdsk /f over the partition in question.


To Install Less Compiler

sudo npm install -g less

To know the location of it

sudo which lessc

To compile ".less" File to ".css"

lessc /home/--Your LESS File Location--/File.less > /home/--Your CSS File Location--/main.css


Change your desktop-enviroment to something lighter.


How can I make keyboard shortcuts register on key release, rather than on key press?

You can achieve it this way:**

Install xbindkeys
sudo apt install xbindkeys

Run the command:
xbindkeys --key

In the white box that appears, Press your key combination. Example Win + E will return the following :
"(Scheme function)"
    m:0x50 + c:26
    Mod2+Mod4 + e

Now copy the last (or last second) line and use it as given below.
In newer versions before you need to do this, which let you jump the next step:

Please, create one with 'xbindkeys --defaults > /home/$USER/.xbindkeysrc'.
or, if you want scheme configuration style,
with 'xbindkeys --defaults-guile > /home/$USER/.xbindkeysrc.scm'

Create a new file .xbindkeysrc in your home Directory
touch $HOME/.xbindkeysrc

Open it
nano $HOME/.xbindkeysrc

Enter your required command and keys as given below
"nautilus"
    release+Mod2+Mod4 + e

(Note: Don't forget release , Replace "nautilus" with any command.)
Similarly add all the requires command-key combinations one below the other

Now add xbindkeys to xinitrc:
sudo nano /etc/X11/xinit/xinitrc

add xbindkeys to the starting (1st line or before . /etc/X11/Xsession)

Reboot your system and you should get expected behavior
TIP: Make sure you don't set conflicting configurations in xbindkeys and your GUI method provided by your DE
For more examples, man xbindkeys.


Add folders in ubuntuone with kubuntu 11.04

You will find almost everything you need here:

https://wiki.kubuntu.org/UbuntuOne/Tutorials/Files


error: file '/grub/i386-pc/normal.mod' not found

Grub has a small core image that is loaded at boot time. The core image dynamically loads modules which provide further functionality. i386-pc/normal.mod not found indicates that grub can not load normal.mod, which is a grub module that provides the normal command. To load normal.mod you need to tell grub where it is. To do this you can use the grub command-line (aka Rescue Console). Grub will start the command-line if there is a problem booting, or you can start it manually by holding the shift key as grub starts (to force show the grub menu), and then pressing the 'c' key.

Using grub you can explore the drives, partitions, and filesystems. You need to:

locate the grub install using ls or search.file
set grub variables $prefix and $root
load and run the normal module

Example

The following is just an example. You will need to adapt it to your local drive and partition setup.

where is normal.mod? look in some likely locations

grub> search.file /i386-pc/normal.mod
error: no such device: /i386-pc/normal.mod

grub> search.file /grub/i386-pc/normal.mod
error: no such device: /grub/i386-pc/normal.mod

grub> search.file /boot/grub/i386-pc/normal.mod
hd0,msdos1

If you get "Unknown command 'search.file'" this means that the search.file command is not available. This is probably because you are at the grub rescue> prompt and not grub> prompt. In this case you can still carry on and use the ls command and your knowledge of your partition layout to find normal.mod.

found it at (hd0,msdos1)

grub> ls (hd0,msdos1)/boot/grub/i386-pc/normal.mod
normal.mod

why did grub not find it?
check $prefix - absolute location of the grub directory
(this is  set when grub is installed by grub-install)

grub> echo $prefix
(hd0,msdos2)/boot/grub

check $root - default device for paths that do not include a device
grub initially sets this to the device from $prefix

grub> echo $root
hd0,msdos2

root and prefix are pointing to the wrong partition (hd0,msdos2)
set $root and $prefix to the partition where we found normal.mod (hd0,msdos1)

grub> set root=(hd0,msdos1)
grub> set prefix=(hd0,msdos1)/boot/grub

load and run normal module

grub> insmod normal
grub> normal

Some other commands that may be helpful

ls list all devices and partitions

grub> ls
(hd0) (hd0,msdos5) (hd0,msdos1)

ls partition

grub> ls (hd0,msdos1)
        Partition hd0,msdos1: Filesystem type ext* - Last modification time
2014-05-08 15:56:38 Thursday, UUID c864cbdd-a2ba-43a4-83a3-66e305adb1b6 -
Partition start at 1024KiB - Total size 6290432Kib

ls filesystem (note / at end)

grub> ls (hd0,msdos1)/
lost+found/ etc/ media/ bin/ boot/ dev/ home/ lib/ lib64/ mnt/ opt/ proc/
root/ run/ sbin/ srv/ sys/ tmp/ usr/ var/ vmlinuz initrd.img cdrom/

look inside /boot/grub
presence of i386-pc directory means this is a BIOS install
presence of x86_64-efi directory would indicate an EFI install

grub> ls (hd0,msdos1)/boot/grub
i386-pc/ locale/ fonts/ grubenv grub.cfg

Grub Manual: Troubleshooting: GRUB only offers a rescue shell covers the basic recovery method described above
For available commands and variables see Grub Manual: The list of command-line and menu entry commands and Special environment variables.
It may be possible to load other missing modules e.g. if the search or search.file commands are not recognised set $prefix correctly and then do insmod search, for ls do insmod ls etc. Run find /boot/grub -name *.mod on a working Linux install to see all of the dynamically loaded Grub modules.
You can always just boot from external media and re-install Grub.


Installed Typecatcher Fonts Not Showing Up in Inkscape?

I had this issue in both Inkscape and GIMP. The font worked in LibreOffice but not these other applications. I installed the fonts with the common method of right-clicking on the font file, and then choosing Open with Fonts from the menu that pops up.

What I did is create a .fonts folder in the Home directory, and copy the font files there. Then they worked.

Folders that start with a . are normally hidden, as they contain system stuff and changing them can cause problems easily.  In the Files utility, you need to click on the icon with three bars on the right of the menu bar, and then click on the checkbox next to Show Hidden Files. Then make sure you are in the Home directory, go to that same menu and click the icon to create a new folder, and name it .fonts.

Now go to the Downloads folder, find the font files you want to install, make sure they have been unzipped, and then copy those files to the .fonts folder.


How to add a directory to PATH in Linux ? I am using Windows Subsystem for Linux - Ubuntu

As the output suggests, you should run the following in your terminal (if you have not already tried doing so):

sudo apt install gcc-arm-none-eabi


Super+L to lock screen not working after upgrade to Ubuntu 17.10

I'm also having this problem though without the gsettings weirdness. There's a bug report open here https://bugs.launchpad.net/ubuntu/+source/gnome-shell/+bug/1715435


Lost all the software downloaded because of upgrade

Upgrade will keep your (and others) home directory but the installed programs will be purged. You will have to reinstall missing programs but the bright side is that the configuration/preferences for each should be there. Those are being kept in your home folder which is still there.


Unity MT grab Handles plugin disappeared!

I got it back, because I was using unity-5.X that does not include the plugin.
Now it was restored.


How do you install the MAAS Image Builder on 14.04 LTS

Rough steps I followed to get it working.  Note it doesn't appear that the image builder is in the main areas or at least I had issues with that.  Some of these steps MAY not be necessary.

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

sudo apt-get bzr
sudo apt-get -y install make python-virtualenv
bzr -Ossl.cert_reqs=none branch lp:maas-image-builder

cd maas-image-builder
make install-dependencies
make
sudo ./bin/maas-image-builder -o centos7-amd64-root-tgz centos
sudo ./bin/maas-image-builder -o centos6-amd64-root-tgz centos --edition 6


Custom Keyboard Shortcuts to Programs not working after upgrade to 11.10 from 11.04

In Ubuntu 11.10 there seems to be a bug that prevents the "custom shortcuts" keys from working for favourite keys 3, 4 and 5 on the Microsoft 4000 keyboard. Maybe the x41's non-standard keys have a similar problem? Here's what worked for me:

In a terminal, run: gconf-editor
Navigate to apps/metacity/global_keybindings
Change "run_command_3" to be 0xc2, "run_command_4" to be 0xc3, and "run_command_5" to be 0xc4 - these corresponds to the 3 / 4 / 5 favourite keys for the MS 4000 keyboard. Note: the x41s keycodes are likely to different, so sorry but I don't know what the corresponding keycodes are.
Navigate to apps/metacity/keybinding_commands, and bind these run_command keys.
For example, change "command_3" to be the take-screenshot command: gnome-screenshot --window --interactive
Customize "command_4" and "command_5" as desired.


In the wordpress admin console, go to tools -> export -> download export file.

Alternatively dump the DB to mysqldump & tar up your wordpress directory.


This is a bug in the avg2012flx package, specifically in its post-installation script. It looks like this version of the package doesn't handle upgrades properly.

The easiest solution would be to wait for a fixed version of the package. Since this seems to be a third-party package, you'd have to report this as a bug to whoever made that package.

You should be able to work around the bug by moving the /etc/init.d/avgd file out of the way:

sudo mv /etc/init.d/avgd /etc/init.d/avgd.old
sudo apt-get -f install

This may leave avgd in a non-working state or cause other trouble. Alternatively, reinstall the old, working version of the avg2012flx package and mark it as on hold until a fixed version comes out.


Can't install aptik package on ubuntu 15.04

There is no reason that the package can not be located in Ubuntu 15.04.
The package is present in the repository and has a Vivid Vervet version.

Please make sure you properly ran those three commands :

sudo apt-add-repository -y ppa:teejee2008/ppa
sudo apt-get update
sudo apt-get install aptik


Use move in terminal to move your fonts:

sudo mv ~/.fonts/name.font /usr/share/fonts/

After, rebuild your cache:

sudo fc-cache -f -v


Ubuntu 17.10 no sound on cherry trail laptop

The above solution Will solve the problem sound but only headphones work..
Use the kernel 4.19 It supports the device well speakers will work
Disable/ enable the sound card whenever you change the port
Use alsamixer to look for left and right controls (HPO L...)


Wine isn't showing up anywhere on Ubuntu

I managed to fix my problem by installing wine from HQ repository.
see how : https://vitux.com/how-to-install-wine-on-ubuntu/
after installing, I found wine by right clicking on the exe file and selecting "open with other application"


How to find the terminal command executed by any mouse event

This is best explained by an example:

Take the simplest C program in the world:

    #include <stdio.h>
    main()
    {
      printf("Hello World!");
    }

2. Take the simplest bash program in the world:

    #!/usr/bin/env bash
    echo "Hello World!"

Now place both programs on an icon on the launcher.

Although both programs have the exact same effect on your Ubuntu system, in the second case, we can say that the terminal command being executed is echo "Hello World!".

However, in the first case, there just is no terminal command being executed as the terminal isn't involved  at all! Unfortunately for you, most of the stuff inside Ubuntu (drawing menus, drawing icons, displaying a cell in a spreadsheet, right-clicking a word in a document, ...)  doesn't involve the terminal at all.


I am having trouble switching between my two AMD GPUs using Prime in Ubuntu 17.10

I never used --setprovideroffloadsink. I just prepend DRI_PRIME=1 to the program that I want to use with my dGPU. It always worked fine.

You can check your GPU usage with radeontop to see if it is really used. Though I have hybrid graphics with Intel+AMD. I do not know what radeontop shows with 2 AMD GPUs.


Better use Ubuntu 15.10.
I guess your Problem is that you choose the wrong place for installing the bootloader.
Probably /dev/sda is the right one. NOT /dev/sda1 /dev/sda2...
See here:
http://www.dedoimedo.com/images/computers_years/2014_1/ubuntu-install-bootloader.jpg


Is there a difference between the 'acer-wmi' and 'acer_wmi' drivers?

There is no difference.

acer-wmi.ko is the name of the module (driver) file, while the actual module, following Linux naming conventions, is called acer_wmi.

References in forums, blogs, etc. may use both conventions. Kernel logs, etc. should use acer_wmi.


This script should do the trick:

#!/bin/bash
case $1 in
    "resume")
    iwlist scan
    ;;
esac

Follow these steps:

Open a Terminal.
    Write this command and enter your password when
    prompted: sudo gedit /etc/pm/sleep.d/iwlist_resume
Paste the
    script on the gedit window, save and close.
Give the script
    execution permissions: sudo chmod +x /etc/pm/sleep.d/iwlist_resume


Nvidia: Xorg crashes on 15.04: "drmSetMaster failed: Invalid argument"

First I switched to a console (CTRL-ALT-F1).
Then I removed all nvidia stuff with

sudo apt-get autoremove --purge nvidia-*

and reinstalled the nouveau driver using

sudo apt-get install --reinstall xserver-xorg-video-nouveu

then

sudo reboot

I know this is probably not what both of us want but it is still better than no desktop at all...

My Setup (for completeness):

OS: Ubuntu 15.04
CPU: Intel i5-4570S
GPU: Nvidia GeForce GT 610


Additional Drivers for AMD Graphic Card have not been installing

I recommend you install the default option of fglrx on ubuntu repositories instead fglrx-updates. Follow the instructions below to solve this issue.

On the console (Ctrl+Alt+F1)

Uninstall and remove all configuration files:

sudo apt-get purge fglrx*

Install the proprietary package on Ubuntu repositories:

sudo apt-get update && sudo apt-get install fglrx fglrx-amdcccle

Create a new xorg.conf

sudo aticonfig --initial

Restart the PC

sudo reboot


ubuntu 18.04 software-properties-gtk failing

Probably the same issue and the solution is shared here
According to Tim Richardson:

The package python3-six was installed (so my package manager said).
when I reinstalled this package, software-properties-gtk worked again.

You may try to install python-six package and reinstall software-properties-gtk aftermath.
sudo apt install python-six

Or you may want to install it via pip
pip install six

After you installed python-six package, reinstall the software-properties-gtk like
sudo apt install --reinstall software-properties-gtk

Hope it solves your problem.


How can I change my firewall settings in dependency of my network environment?

Solution would be:

Identify the network address for your home network or any other you want to associate a port with.
Tell ufw to allow traffic from that network via that port like so:

sudo ufw allow from 15.15.15.0/24 to any port 873

# another example

sudo ufw allow from 192.168.1.215 proto udp to any port 88

Note:

The ports chosen are purely imaginary pick that which fits your setup, same situation for network address.


How to mount a vdi file in ubuntu 13.10?

Running Ubuntu 14.04 with Virtualbox 4.3.10 I installed the package by forcing dpkg.

sudo dpkg -i --force-depends virtualbox-fuse_4.1.18-dfsg-1ubuntu1_amd64.deb

Everything worked just fine after that.

When you mount the vdi file it just gives you access to the partitions, but you need to then mount the partition somewhere.  For example:

mkdir ~/vdisk
mkdir ~/part1
sudo vdfuse -f Machine.vdi ~/vdisk
sudo mount ~/vdisk/Partition1 ~/part1


Clicking in ssh terminal causes 'junk' characters [0;83;32M0] after tmux

These are escape sequences that tell tmux about mouse events. Because tmux was disconnected unexpectedly it didn't get a chance to turn mouse mode off so the terminal is still sending them even though no application wants them. You can run "reset" to turn it off.


Use nano to change an "on" to "off" line in read only file

After opening nano, you can use the arrow keys to get to the part of the file you want to change. Then, just like any other text editor, use Backspace to delete the characters you don't want, and any other key on the keyboard to add the ones you want. When you're done, Ctrl+X (for Exit). This will give you a message like this:

Press Y if you would like to save changes, N if you want to ignore the changes, and Ctrl+C if you want to go back to editing the file.


i can't install codeblocks ID from terminal or ubuntu software centre

Referring to your comment that it works now:

sudo dpkg --add-architecture i386
sudo apt -get update
sudo apt-get install codeblocks

That's it! :)


How can I install multiple versions of Android Studio in Ubuntu 14.04?

That's the whole point of the /opt directory. Install from source the versions you want to work on into different directories (it is custom to include the version number in the directory). Like so:

/opt/android{version}/

And you can start both from the executable inside /opt/android{version}/
If you create a symlink

/opt/android

to

/opt/android{active_version}/{executable}

you can use "android" as a command to start that one.


Nautilus - Connect to Server option not visible

You should:

Enable leftside bar with F9 (skip this step if it is already enabled).
Click on Other locations
Find Connect to Server in the buttom of the window:

Enter address with protocol - one from

AppleTalk - afp://;
File Transfer Protocol - ftp:// or ftps://;
Network File System - nfs://;
Samba - smb://;
SSH File Transfer Protocol - sftp:// or ssh://;
WebDAV - dav:// or davs://.

Note: you can specify username directly by sftp://username@server or wait for authentication window to pop up after next step.
Click Connect

Simpler method is to press Ctrl+L to access the address bar and then type the address here and press Enter.


Tomcat runs java by creating a _RUNJAVA variable in setclasspath.sh. This is made up by appending /bin/java to the JRE_HOME environment variable. Your JRE_HOME is currently set to /usr/bin. So you need to modify the JRE_HOME to be /usr instead.

You can override it for the startup.sh script by prepending it like so:

JRE_HOME=/usr ./startup.sh

If you want to modify the JRE_HOME permanently across the system add it to, or edit /etc/environment.


You should be able to remove wacom entries from the interface by renaming or deleting the /usr/share/applications/gnome-wacom-panel.desktop file.

To rename, run the following, then logout/login.

cd /usr/share/applications

sudo mv gnome-wacom-panel.desktop gnome-wacom-panel.desktop-renamed


I tried installing doublecmd-common and there wasn't any shortcut in the menus created, I did get these files installed:

$ ll /usr/bin/dou*
lrwxrwxrwx 1 26 Jan 30  2014 /usr/bin/doublecmd -> ../lib/doublecmd/doublecmd

$ ll /usr/lib/doublecmd/
total 24
lrwxrwxrwx 1   25 Jan 30  2014 doc -> ../../share/doublecmd/doc
-rw-r--r-- 1 6517 Jul 10  2011 doublecmd.ext.example
-rw-r--r-- 1 3966 Apr 10  2012 doublecmd.xml
lrwxrwxrwx 1   30 Jan 30  2014 language -> ../../share/doublecmd/language
-rw-r--r-- 1 5000 Jun  8  2013 multiarc.ini
lrwxrwxrwx 1   29 Jan 30  2014 pixmaps -> ../../share/doublecmd/pixmaps
-rw-r--r-- 1  439 Aug 19  2012 pixmaps.txt

There is no /usr/lib/doublecmd/doublecmd , so nothing runs.

I'll try installing doublecmd-gtk... now

$ ll /usr/lib/doublecmd/
total 9124
lrwxrwxrwx 1      25 Jan 30  2014 doc -> ../../share/doublecmd/doc
-rwxr-xr-x 1 9317564 Jan 30  2014 doublecmd
-rw-r--r-- 1    6517 Jul 10  2011 doublecmd.ext.example
-rw-r--r-- 1    3966 Apr 10  2012 doublecmd.xml
lrwxrwxrwx 1      30 Jan 30  2014 language -> ../../share/doublecmd/language
-rw-r--r-- 1    5000 Jun  8  2013 multiarc.ini
lrwxrwxrwx 1      29 Jan 30  2014 pixmaps -> ../../share/doublecmd/pixmaps
-rw-r--r-- 1     439 Aug 19  2012 pixmaps.txt
drwxr-xr-x 7     140 Dec 18 12:19 plugins

Now there is an executable file and a shortcut, the program runs. Did you install the right packages?


What is the relationship between Ubuntu's version of Kodi and its developer's version?

Both versions are 16.1 and are very close at least (if not exact version). The number 2 before 16.1 separated by : is called an epoch, and sometimes used to distinguish versioning of packages with two very diverse development track.

Read more about this special number here Why do some packages have extra numbers on the front of their version string?


Wifi drops and won't reconnect until reboot (14.04 with RTL8723BE)

I have same problem. For me, work-around is to remove and reinsert rtl8723be module:

root@lenovob5400# rmmod rtl8723be && modprobe rtl8723be

Sure it's not a solution, but better than rebooting.
What a shame Ubuntu does not work with such popular wifi card.

BTW, I tried kernel 3.15, but it has same issue (and few others).

Looking forward for better solution. Go get it hackers! ;-)

Update:

Friends, please vote on related ubuntu bug.

Update 2:

Upcoming ubuntu kernel 3.13.0-25.47 have #1240940 bug fixed,
however, after installing this kernel from ppa, the rtl8723be module is there indeed, but I was not able to connect at all.
Currently I am using standard 3.13.0-24-generic kernel with rtl8723be kernel module from:
https://github.com/lwfinger/rtl8723be.git at 604aa9058fb9e5bb1cf571c99989d081f8fc8b9b commit.

Update 3:

I tried ndiswrapper 1.9 with winxp 64 drivers (and man others). All failed to load:

[  327.503426] ndiswrapper version 1.59 loaded (smp=yes, preempt=no)
[  327.517958] ndiswrapper: driver netrtwlane (Realtek Semiconductor Corp.,08/02/2013,2010.5.0724.2013) loaded
[  327.519049] ndiswrapper (NdisWriteErrorLogEntry:188): log: C0001388, count: 1, return_address: ffffffffa05e5d9f
[  327.519052] ndiswrapper (NdisWriteErrorLogEntry:191): code: 0x605
[  327.519143] ndiswrapper (mp_init:211): couldn't initialize device: C001001E
[  327.519146] ndiswrapper (pnp_start_device:395): Windows driver couldn't initialize the device (C0000001)
[  327.519150] ndiswrapper (mp_halt:254): device ffff8800cd747880 is not initialized - not halting
[  327.519151] ndiswrapper: device eth%d removed
[  327.519380] ndiswrapper: probe of 0000:04:00.0 failed with error -22

I tried one more trick - added fwlps=0 parameter for the rtl8723be module.
So far so good. We will see...


AudioEngine D3 USB DAC - volume either 0% or 100% via volume keyboard keys, alsamixer works fine

I just got the D3 today and had this exact same problem. Check out the top answer on this thread. For me, these instructions worked:

  There are a few variables which control how PulseAudio controls the volume. You can either edit /etc/pulse/default.pa (you'll have to be root to do that) to change the behavior for all users, or copy that file to ~/.pulse/default.pa and then edit that file, to change behavior for the current user only.

  Open the file mentioned above. Find the row saying load-module
    module-udev-detect and change it to:

  load-module module-udev-detect ignore_dB=1

  To try your changes, restart PulseAudio with the following command:

  killall pulseaudio

  PulseAudio will then autospawn (restart itself).

I had a block in the config file that looked like this:

### Automatically load driver modules depending on the hardware available
.ifexists module-udev-detect.so
load-module module-udev-detect tsched=0
.else
### Use the static hardware detection module (for systems that lack udev support)
load-module module-detect
.endif

Then I simply added ignore_dB=1 to the end of each load-module line, so that the two lines looked like

load-module module-udev-detect tsched=0 ignore_dB=1
...
load-module module-detect ignore_dB=1


Skype video not working after upgrade from 11.10 to 12.04

The path to v4l1compat.so has been changed. So, you should use the command:

LD_PRELOAD=/usr/lib/i386-linux-gnu/libv4l/v4l1compat.so /usr/bin/skype


How can I use box.com to sync my home directory across machines?

Officially Box Sync client for Linux does not have and has no plans for development because it is not a priority. Although this method can assess alternative.
First of all you need to install the davfs2 package. You can do this by issuing the following command in terminal: (or you can also use your favorite package manager to install WebDAV)
sudo apt-get install davfs2
sudo adduser username davfs2

Now you should create a dedicated box.com folder.
mkdir /home/username/box.com
echo "https://dav.box.com/dav /home/username/box.com davfs rw,user,noauto 0 0" | sudo tee -a /etc/fstab
sudo chmod u+s /usr/sbin/mount.davfs

Now you have to switch to a regular system user. This can be accomplished by issuing the following command:
su username

Next you should disable the file locks in your davfs2 configuration file, insert your box e-mail and password, change the privileges to the secrets file containing your credentials and finally to mount your account:
echo "use_locks 0" > ~/.davfs2/davfs2.conf

If this command gives you "No such file or folder" error, just create the folder and file with the command below
mkdir ~/.davfs2/
touch  ~/.davfs2/davfs2.conf

then proceed with these commands.
read -p "box.com email: " boxuser
read -sp "box.com password: " boxpass
echo "https://dav.box.com/dav $boxuser $boxpass" > ~/.davfs2/secrets
chmod 600 ~/.davfs2/secrets
mount /home/username/box.com

Initially it may take some time in order to synchronize all of the files in your box with the newly created folder but after that you should be able to create, delete and overwrite all of your files.


Delete all Ubuntu partitions and reinstall again

If you have Windows on third partition then should be ok delete these two partitions and create just one. When you will install Ubuntu on that second one with live CD, GRUB will install with it too. So GRUB should autodetect your Windows on your first partition and let you choose what to boot on computer startup.


Which hidden folder in my home folder contain the data for the Passwords and Keys application?

The folder in the Home folder is:

~/.gnupg


I found a file path, but I can not open it

If by "Ubuntu Terminal" you mean Windows Subsystem for Linux (WSL) you can find WSL files by entering the following in the Windows file explorer:
\\wsl$\Ubuntu

Or, depending on your Windows version, simply:
\\wsl$

You can find more info in this Superuser question


Can I merge /dev/sda2 and /dev/sda4 without messing up /dev/sda3 and /dev/sda4?

You can only merge partitions that are next to eachother.

  Also, do I have to do something like Removing Windows before deleting /dev/sda2?

No. If you delete sda2 you basically delete Windows.

--

What I would do since there is no need messing around.

Create a live gParted dvd.

and then ...

delete sda2.
format it as EXT4.
mount /home/ in sda2.

The more difficult method ...

delete sda2 and leave unallocated
add that space to sda3
shrink sda3 so that the empty space is at the end of sda3
add space to sda5

That will take hours and hours and hours to finish (the less free space there is the longer this will take since files will be moved to the beginning of sda3).


3D GPU acceleration on AMD graphics with mesa drivers?

While I haven't used it myself, this question indicates you will need ocl-icd-opencl-dev installed. Note that opencl is only used for cycles rendering and compositing.

Blender's UI is drawn using opengl and the mesa libraries will provide gpu acceleration for updating blender's window.


Instead of using xampp i would recommend to install the ApachePHPMySql thingy in ubuntu.

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

EDIT: The ubuntu phpmyadmin documentation is found here: https://help.ubuntu.com/lts/serverguide/phpmyadmin.html


Where is the user's profile picture stored in Unity?

I've been looking around for that location, and found the solution in another question (specifically related to Gnome 3 though).

The picture is a simple png file named .face and stored in your home directory.
A simple copy/paste there will do the work: you can check the result in System Settings/User Accounts.


Redshift and flux f.lux both installed but no visible effect from either

Another option is to install xcalib via sudo apt-get install xcalib

Then, you can invert the screen colors which again maybe too harsh because black will become white or, and this is what I prefer, you could reduce the screen contrast using

xcalib -co 75 -a

or any other value you feel comfortable with.

And you could reverse the effect with

xcalib -c

Obviously, you could set up a keyboard shortcut for the above to save typing in a terminal. How exactly you add the keyboard shortcut depends on your distro.


found the extension to do this: Panel Settings


What are the legal consequences of customizing the LiveCD?

Start by reading the Derivative Distro Howto.

You can certainly make a distribution based on Ubuntu, and as far as I know there is no specific restriction on the live CD, so you can make derivative works based on it.

The code isn't be a problem: as far as I know it's all freely redistribuable software, Ubuntu doesn't have any specific rights to distribute that you don't also have. But the branding — trademarks and artwork — might be. The obvious thing you should check is what you may do with the Ubuntu artwork, and how you're allowed to use the name (it's trademarked).

A typical example of artwork and trademark-related limitation is the Iceweasel saga. The Mozilla foundation wants only “acceptable” derivatives of Firefox to have the Firefox brand, so even though the software is free software (as in free speech), the branding is not. Although the Mozilla foundation was prepared to trust Debian to make only acceptable changes, such as security fixes, they were not willing to extend that trust to others. But the Debian Free Software Guidelines specify that the “license must not be specific to Debian”, so that people in your position know that they can make derivatives. Since no acceptable compromise was found, Debian does not distribute “Firefox”, it distributes “Iceweasel” with the same code and different branding.

Ubuntu is less strict on that point, so if you want to make a derivative, you do have to check whether you may retain the branding on any component you change (starting with the distribution as a whole).


iptables is part of the kernel / netfilter.  It's not a specific service or program that you can 'start' or 'stop'.  It's ever-present, the only thing of relevance is what rules are loaded into it at a given time.

That means that the iptables command you call is actually just a front-end that helps with understanding / reading / interpreting / configuring the underlying netfilter rules at the system/kernel level for that boot session.  There is no given 'program' you can start or stop to disable iptables - there's commands you can run which do this (such as iptables -F among others), but there's no specific service to start or stop.

In comments, you refer to "other people" saying that it is a service.  In many cases, this isn't actually a service per-se, it's just a service-executable script which handles loading / unloading iptables rulesets.

There may be other distributions that ship these types of service scripts that manipulate iptables - indeed, I myself have a service script on my computer that has a 'start' and 'stop' call which either loads iptables rules from a file, or correspondingly clears out all rules and sets things back to the system default of 'accept all'.  This is, however, not shipped in the Ubuntu repositories, it's a script I wrote (and for 'fragile code' reasons I am not willing to share this at this time).

Ubuntu doesn't provide such service scripts for iptables.  You would need to write your own.  Or, consider using ufw if you want something simpler to maintain that you can load with system utilities (though, these are also 'scripts' that more or less control whether the ufw-defined rulesets are enabled or not, and you're really supposed to use ufw enable / ufw disable instead of those service scripts).


How to connect to SSH on a computer on different network?

Ok, first of all DynDNS != ISP port blocking or anything of that like.

Your ISP won't block ports on your router unless they use them for remote connection support or whatever other reason.

By default every router has a firewall that blocks all port access from the outside which is good for the normal user, you don't want to create
vulnerabilites to people that have no idea what they are doing on the internet.

Now what you have to do is not only portfoward but also allow access on those ports from the outside in the router firewall. These are 2 seperate things.

And in general it is a good idea to not use the default SSH port on the outside, since you can portfoward e.g. external port 53299 -> internalmachineip:22 it is a lot saver to just use a non default port to go past all those automatic crawlers.


how do i get a networkManager on a machine with no network

Now that the ethernet is working, let's reinstall Network Manager. It comes in a few versions so we'll have to do some guesswork. Please open the terminal and do:

sudo apt-get update
sudo apt-get install network-manager

See if you can then start it:

sudo service network-manager start

Post any errors or warnings.

I think the link you posted for wireless is probably correct.


Because cron runs commands non-interactively, there is no way for sudo to authenticate.

For commands that require root permission, you should use root's crontab (i.e. sudo crontab -e instead of plain crontab -e) and then avoid the use of sudo within your commands and scripts altogether.

You should also give the full path to the script - preferably locate it some systemwide e.g. /usr/local/bin/clear_mem.sh in place of ~/clear_mem.sh


Thank you @oldfred for your help!

So I proceeded with several things:

In /etc/default/grub I changed the nvme.core to a value of default_ps_max_latency_us=0, so I switched off APST.
In /etc/default/grub I added nomodeset, according to
How do I set 'nomodeset' after I've already installed Ubuntu?
I followed the instructions on https://itsfoss.com/update-firmware-ubuntu/ , using the tool fwupd to update my firmware.

The booting works! At least this one time now.

Anyone feel free to edit/post answer with technical insight, because in the end I still don't know what exactly was the problem. I just hope it works now :) I'll edit this post if anything happens.

EDIT:

Today the same problems occured again; I cannot boot into ubuntu, it seems like almost the disk cannot be read. I will try to check the disk sanity. Also, this message appeared cannot start pxe over ipv4.

1 in 30 reboots might work, the other 29 fail. And in this one time the system normally crashes/freezes after some time.

EDIT 2: I contacted Lenovo, it seems like my SSD is broken, they are sending me a new SSD.


When you use software to capture packets on your internal network behind a NAT router, you'll be capturing local traffic.

In that case, you will need to:

turn on the router logging (preferably logged to your machine) and cross-reference whatever the router logged with whatever you captured on your machine.

OR

disconnect the router and hook your machine directly to the Internet and capture Internet traffic directly.


Ubuntu on HP Pavilion g7 1153er with hybrid radeon 6470M and Intel 3000

I have posted one forum and I have got reply with suggestion to try "acpi_backlight=vendor" option for grub. This helped a lot. With using acpi_backlight=vendor option without nomodest I have seen right graphics for ubuntu 12.04 but havent set hybrid graphics there right.

Than I have tried to do the same with Ubuntu 13.04. And made:

1) “acpi_backlight=vendor” option in start line for installation Ubuntu 13.04

2) after installing OS all grub options left configurated in grub. So I have installed intel driver than(https://01.org/linuxgraphics/downloads)

3) checked grub configuration,

 $ sudo gedit /etc/default/grub

keeped “acpi_backlight=vendor”, and removed “nomodeset” from there and got GRUB_CMDLINE_LINUX="acpi_backlight=vendor"

saved config file and updated grub

$ sudo update-grub

4) installed ati catalyst according to http://wiki.cchtml.com/index.php/Ubuntu_Raring_Installation_Guide#Installing_Proprietary_Drivers_a.k.a._Catalyst.2Ffglrx

And after this steps I have got all my problems solved

The main reason of atiddxProbe: fail to probe intel VGA device was using of “nomodeset” at grub for boot without black screen but “acpi_backlight=vendor” helped a lot.


Disable "System program problem detected" for segfaults in my own programs

I've noticed this was fixed since I asked this question on Ubuntu 16.10. Userspace programs that weren't installed from a package and don't have a signed .desktop file associated with them no longer issue a dialogue like this.

This answer can't really apply to older versions of Ubuntu, though I would still be interested to know the answer for older versions.


Ubuntu Touch: How can I debug ubuntu touch apps on the device?

First, you need to make your system partition writable by doing 1:

touch /userdata/.writable_image

and rebooting your phone/tablet. Be aware that you cannot install over-the-air (OTA) updates after doing this. Then you need to install gdb:

apt-get install gdb

Finally, when launching the app from Qt Creator like shown here, instead of pressing the "Run" button, press the "Debug" button below. It should then launch the app through gdbserver and show the debugging interface in Qt Creator.

That's the theory. However I didn't get it running. Qt Creator spits out various error dialogs, some saying "Unknown Error", others having no text at all. I'm currently trying to run my application from the command line on my Nexus 4, which is incredibly difficult.


Mosquito Server Refuses Connections Ubuntu 18.04

I'm posting this as an answer so I can give more detail in case anyone stumbles upon this in the future.

Setting up the MOSQUITTO MQTT Server in Ubuntu 18.04 is actually not hard, but the steps are important.

Step 1: Install Mosquitto Software

sudo apt-add-repository ppa:mosquitto-dev/mosquitto-ppa
sudo apt-get update
sudo apt-get install mosquitto

Step 2: Open Port 1883 and start firewall

sudo ufw allow 1883
sudo ufw enable

Step 3: Verify Mosquitto is not already running

pgrep mosquitto

[Note, if any number shows, that is the PID of an already running Mosquitto. You can just kill it. Also, you can try: sudo service mosquitto stop]

Step 4: Start Mosquitto with verbose option

mosquitto -v

[Note: This starts Mosquitto without using any config file. It echos connection and status information to the screen. Easiest for quick debugging.]

Step 5: Check connectivity using local host

Go to your client machine (in my case a Windows 10 laptop) and run the MQTT client, connecting to the local address of the Linux Mosquitto server (in my case 192.168.0.144). You should be able to connect. In fact, you can do this step before you even open the firewall, since this is all on the local network, the firewall rules are irrelevant at this point. Until next step which is...

Step 6: Check Connectivity using web tool

use either: www.yougetsignal.com/tools/open-ports/   or
https://canyouseeme.org/

[NOTE: You will not get an OPEN state UNLESS THE MOSQUITTO BROKER IS RUNNING]

Step 7: If Port Shows Closed When coming In from Internet (ie not localhost)

Here's where I got tripped up. In my case, I have a Verizon Modem that ALSO has a firewall (because it has a router). I have my own wireless router, a tp-link Archer C1200, that I have plugged into the Fios Modem/Router. I started by putting the port forwarding in the tp-link. But that firewall comes after the Fios firewall so I needed to go to the first wall and do the port forward there.

And this is the second thing that is tricky. All of the online how-to's said I should forward port 1883 to the local IP address of my Linux Server, which in my case was 192.168.0.144. But that was not correct in my case. The Archer C1200 was actually the device that I needed to forward to -- it handled the correct distribution from there. It had an address of 192.168.0.152 assigned to it from the Verizon router. I still have both forwardings in place (ie the Fios and the tp-link) and my guess is that I need them both.

Now all pathways are open, you can follow the other Mosquitto instructions regarding logging, config files, Daemons, etc.

Hope this saves someone some time down the road!


Theme folder - cannot access permissions

You need to run it as root.

sudo -H nautilus  # Replace `nautilus` with your file manager

Then, navigate to your desktop (in /home/username/Desktop), and drag & drop into /usr/share/themes.


If you are looking for a simple rsync command to backup your full filesystem, consider using these options:

# -a --archive
# -v --verbose
# -A --acls
# -X --xattrs
# -x --one-file-system
# --numeric-ids

The -aAX options preserve permissions, mode, owner, group, mtime, ACLs and xattrs. The -v option prints all files being transferred. The --numeric-ids option may be relevant if you sync to a remote location rather than a local disk.

To answer your initial question, you are likely interested in the -x option (--one-file-system). This prevents rsync from descending in other mount points such as /proc and /sys. Note however, that it will also avoid copying /home if that is on a different mount point. In that case you need to run another rsync command for /home/.


You just have to find the right setting.

Open "System Settings..." (for example by clicking on the gear in the top right)
Choose "Universal Access"
Open the "Seeing" tab if not already in focus
Toggle the switch next to "Screen Reader"

You can also toggle Screen Reader using the shortcut Alt+Super+S.

If neither of those work try killing it and uninstalling as described here.


After a downloading has finished, it should be deleted auto but sometimes Desktop (or Nemo, Nautilus etc.) need a refresh (F5), then it will disappear.


I have character on keyboard, but I can't input it

Check your Layout Chart  by following below images. For english it should be like this:

So, to use | character, press Shift+\.

If you use another input language, this Layout Chart it will look different. So you need to check how.


How can I make "rm -rf / " into an alias?

This would be much better done by applying the appropriate permissions to
prevent people from deleting stuff.

This aliasing ‘security’ approach would be easily overridden by disabling the alias, symlinking to rm and running it that way, copying the rm binary, or possibly even running it directly.

You should secure your desktop by pressing Ctrl+Alt+L to lock it when leaving it unattended.


Is it save to delete the akonadi file_db_data?

In general: things that reside in ~/.local/ in a sub-directory belong to the software that the directory is named after. file_db_data belongs to akonadi so deleting the file will affect akonadi. If you do not care about that anymore it is safe to delete both the file and the directory.

This:

sudo apt-get remove --purge kmail akonadi-server

should also remove that directory and the file. It will not delete krusader.


Why does the newest version of Ubuntu (18.04) have 8 years old x11vnc?

Looking at https://packages.ubuntu.com/bionic/x11vnc i can see it's in 'universe', ie. community supported. This means no-one in the community has grabbed, compiled, tested & packaged the latest version.

You're welcome to do these if you can & wish, or you could 'file' a bug suggesting it be done too (when the MOTU & others find the time to do it).

The reason is not many in the community step forward & help, leaving it for a very small number of volunteers.


I have the same issue on a Taichi X370 motherboard and 1050Ti GPU with the MOK management menus not being visible. I tried enrolling a key in a vm just to see how the menu layout looked.

With the above I could blindly enroll a new key in MOK management.


No, if it's a newer version at all it's only slightly newer. Intel's graphics drivers are open-source and use the Mesa OpenGL implementation, so they are included by default in Ubuntu. If you want a "bleeding-edge" development version, you may want to check out adding the Oibaf or Padoka PPAs.

However, I would say, "if it ain't broke, don't fix it."


Add an eSATA drive with bootable Ubuntu 16.04 to a Windows 7 UEFI dual boot PC

I recommend using GPT. If the installation creates an entry in the EFI's NVRAM, that entry may or may not survive unplugging the eSATA disk. This is true whether the disk uses MBR or GPT -- that is, it's throwing the dice either way. If you don't intend to boot the eSATA disk on another computer, it might be better to proceed as follows:

Boot the Ubuntu installer in its "try before installing" mode.
Launch a Terminal window.
Type ubiquity -b in the Terminal window. This launches the Ubuntu installer, but -b tells it to not install GRUB.
When you're done, reboot into Fedora and tell it to update its GRUB configuration. (IIRC, grub-mkconfig -o /boot/efi/EFI/fedora/grub.cfg is how you'd do this in Fedora.)

This procedure will cause Fedora's GRUB to retain control of the boot process, and to add an Ubuntu entry to it, rather than have two different GRUBs installed, and possibly battling for status as the GRUB that controls the boot process.

Alternatively, instead of step #4, you could boot into Fedora and install my rEFInd boot manager, which would then take over the role of the program that manages the boot process. rEFInd tends to be a little easier to maintain if you're dual-booting two different Linux distributions.

Note that GPT disks use several GUIDs -- one for the disk itself, one for each partition, and GUIDs used as type codes to identify partitions' intended uses. The first two of those should be unique for each disk and partition, so as to avoid the sorts of conflicts you seem to be concerned about. Unless you do a low-level copy or clone of a disk (and maybe not even then, depending on the software you use and the procedure you follow), two disks should not have shared GUIDs.


How to prevent Unity launcher appearing when using browser back button?

This is not directly related, but if you were having troubles hitting your back button I would suggest you right click and select the back option instead.  Usually this is the faster method any way.

Hope this helps.


I end up creating my own theme after all.

Elementary Freya Theme | XfceLook

Feel free to use it.


where to stick libraries I install myself?

Header files, among other things, tell the compiler what functions, values, etc. exist in a library. Just because you point to the header file it doesn't mean that the linker will know where to look for the corresponding library.  /usr/lib and /usr/local/lib are normally used when installing third party programs. Now, /opt is usually used for programs untar into one folder.

From what I can see you have celt in the /opt/celt folder. Look for there for a file that looks something like libcelt.so. That is were you need to point the linker to. Assuming the file is somewhere in there, then you can point the linker to look into that folder by updating the library path variable as such:

export LD_LIBRARY_PATH=/opt/celt:$LD_LIBRARY_PATH

Then run your configure and make scripts again. You may need to start a clean installation.


Juju won't run on orchestra due to ssh error

If bootstrap has returned, all that means is that juju was able to tell cobbler (the main piece of orchestra-provisioning-server) to boot the machine. If you don't have power control defined for the profiles/systems in cobbler, and/or you don't have PXE boot by default on that machine, you'll still need to manually reboot the server and cause it to PXE boot so that it installs a fresh Ubuntu and starts the juju agents on the first boot.

Also, if you didn't want bootstrap to "take" one of your real machines, you'll need to define a profile for a VM inside cobbler and then pxe boot that VM. Another way to hack this onto the cobbler server while you're still just messing with juju is to just read the pre-seed file that is defined for a fake system, and run the agents/zookeeper directly. That is beyond the scope of this question though.

The bare metal story is still very new in juju (it was as much a Proof of Concept as anything in 11.10), and is still evolving. I'd recommend following its progression on the juju mailing list and in #juju on Freenode, as its likely to get a lot smoother as the use cases become more clear.


Is the system running ouf of memory?

You can have a look in /var/log/syslog to see if you get any OOM (Out Of Memory) messages during the time of day when /etc/cron.daily/apt is running.

/etc/cron.daily/apt is executed at 06:25, but there is a random sleep in the apt script, so it might be up to 1800 seconds later

The command free -m will also be able to tell you how much free memory you have, and vmstat 5 will be able to show you if you have a lot of swapping, or memory movement going on.

If this is the case you might look into adding more swap, adding more memory, or find if you have any unnecessary processes running that takes all of your memory. (A reboot in the case of a memory leak)

Run apt manually?

Have you tried running /etc/cron.daily/apt manually to see if you can any more warnings/errors?

If you are running Ubuntu 14.04 LTS you'll find a call for random_sleep subroutine on line 425. Add a # on this line to not have it sleep before a run.

On Ubuntu 12.04 LTS it is line 423. Ubuntu 16.04 LTS should not have this file as far as I can see.

Run /etc/cron.daily/apt as root like this:

root@hostname:~# /etc/cron.daily/apt

Or with sudo like this:

username@hostname:~$ sudo /etc/cron.daily/apt

There might be some interesting errors to point to you the right direction, or try looking in the /var/log/syslog file for anything suspicious.


Not able to detect DVD in ubuntu 16.04 . At which location DVD will display?

There are some things to check...

Have you installed udftools? If not ...

sudo apt install udftools

udftools is a tool for UDF filesystems (= cd and dvd).
eject -n This should show you the device.
eject or eject -t should eject your DVD.
sudo hwinfo --cdrom should show you info about the DVD.

Please edit results into your question. Since this is partly a comment ... Ill remove it if it has not got a working method.

Generally ...

DVD automatically mount in /media/
In Nautilus DVD will appear in the panel on the left hand side.


How can I solve 'Illegal instruction' crashes with on a Raspberry Pi with Ubuntu Server 21.04

It appears to be a known (and solved bug):
https://tracker.ceph.com/issues/50579
So I'll just have to wait until 16.2.5 is released which should solve my problem.


Windows partition not shown in Ubuntu live session

I used a utility "Test Disk" from AVG (Free, DOS based) and that was able to see all the partitions and I recovered all the data (copied to another USB medium).

Seems there was a corrupted partition table. I formatted the hard drive to factory settings using my laptop's factory image restore dicks.


How to set up a network printer. (shared with windows)

As long as your computers can see each other on the network, you should be able to share with them pretty easily (this works even if you have some computers that are on the network via Ethernet and some that are on Wifi).

The simplest way is to log on to the computer that has the printer connected to it (this is the "server"), go to "Printers," right-click the printer and make sure "Shared" is checked. If not, enable it (this may require you to install CUPS (Common Unix Print Server), which it will prompt you for, if you do).

The other Ubuntu machine should pick it up easily. If it doesn't pick it up automatically, open terminal on your server and type in ip addr and find your wireless connection (usually named "wlan0") and make note of its inet value (usually something like "192.168.1.xxx" where "xxx" is between 2 and 254). Then, on your other Ubuntu machine, in Printers, select "Add Printer". If it doesn't detect it, select "Find a Network Printer" and put in the IP address of the server and click "Find." It should pick it up from there, and the installer will walk you through.

Windows 7 has a networking option called "Home Group", make sure this is turned off (I've found that it tends to interfere with networked sharing on mixed OS networks). You can find it in the "Network and Sharing Center" section of the Control Panel. Once that's turned off, you should be able to find the printer via the "Network Printer" option of the "Printers and Devices" Add Printer wizard.

If the Windows 7 client doesn't see the printer, or won't connect to it, you may need to turn on the Internet Printing Client, as described in this Microsoft Knowledgebase Article, and use the CUPS Windows driver when the printer setup wizard asks for the driver.

Edit: If your computers can't see each other, there are a few things to do:

Make sure file and print sharing is turned on (Windows) If the Windows machine doesn't see other computers, it's likely because File and Print Sharing is turned off. The Microsoft Knowledgebase has detailed instructions, but basically - go to "Network and Sharing Center," find the "File and Print Sharing" options for the details for the network you're connected to, and make sure it's turned on.
Make sure all computers are on the same subnet. An IP address has four sets of numbers separated by a dot. All computers should have the same for the first three sets (such as "192.168.1.xxx"). If they don't, then you'll need to adjust the DNS software of your router to make sure they are all on the same subnet. This will vary by software, so you'll need to consult the manual or community for your particular router.
Make sure the print server is broadcasting the printer. On your print server, open "Printers" and find the "Server" menu. Click on "Settings" and make sure "Publish shared printers connected to this system" is checked, nothing else should need to be checked. (You may need to click "Show printers shared by other systems" on the Ubuntu client for it to see the shared printer.)


Extract number if lines from file in order of date file name

You can do this by combining a few common tools:

find to list all .csv files (unordered) and execute a command for each
basename to extract the file name without .csv extension from the path
date to interpret the date specification in the file name and convert it to an easily sortable number, like seconds since 1970.
echo to print the calculated number and the real file path in one line for each file
sort to sort the file paths according to this converted date number
cut to extract only the file paths again from the combined list
xargs cat to construct a command by passing all file names in order to the cat command for concatenating them.

The complete line looks like this, if all files we want to process are located in a folder named datecsv:

$ find datecsv/ -name '*.csv' -exec bash -c 'echo "$(date -d "$(basename -s.csv "{}")" +%s) {}"' \; | sort -n | cut -d' ' -f2- | xargs cat
2018,1,1,aaa
2018,1,1,bbb
2018,1,2,ccc
2018,1,2,ddd
2018,4,30,eee
2018,4,30,fff

My example files producing the output above are these:

$ cat datecsv/April-30-2018.csv
2018,4,30,eee
2018,4,30,fff
$ cat datecsv/January-01-2018.csv
2018,1,1,aaa
2018,1,1,bbb
$ cat datecsv/January-02-2018.csv
2018,1,2,ccc
2018,1,2,ddd

As you only want the line number of each file, the command for that would look like this:

$ find datecsv/ -name '*.csv' -exec bash -c 'echo "$(date -d "$(basename -s.csv "{}")" +%s) {}"' \; | sort -n | cut -d' ' -f2- | xargs -n1 wc -l
2 datecsv/January-01-2018.csv
2 datecsv/January-02-2018.csv
2 datecsv/April-30-2018.csv

The only change is the last part, where we use xargs -n1 wc -l instead of xargs cat as above.

Some notes: The approach above relies in your file names being a format that date can parse. This is the case for the example names you provided, but it might break if the format changes. It also requires the file name to end with a lowercase .csv. Not sure if some special characters in file names might break stuff (spaces should probably be safe, newlines will surely break it).


Open "System settings > Sound > Sound Effects" and check that alert volume is up.
Also try changing the alert sound in the same tab.

Hope it helps


How do I call FreeMat that was installed via Alien?

I found the answer but looking in the directory /usr/bin/ for anything that looks like freemat and I found FreeMat which means that calling FreeMat should call the program.


How to determine which lightdm greeter is in use?

From a couple of quick tests, it seems the only way is to ask LightDM itself:

$ lightdm --show-config |& awk -F= '/greeter-session=/{print $2}'
kylin-greeter

I started testing with default Ubuntu, then installed lightdm-gtk-greeter and the installed kylin-greeter. In each case, it returned the correct option. For example, after editing /etc/lightdm/lightdm.conf to add greeter-session=unity, the output changed:

$ lightdm --show-config |& awk -F= '/greeter-session=/{print $2}'
unity

$ lightdm --show-config
   [LightDM]
A  backup-logs=false

   [Seat:*]
B  greeter-wrapper=/usr/lib/lightdm/lightdm-greeter-session
C  guest-wrapper=/usr/lib/lightdm/lightdm-guest-session
D  user-session=ubuntu
I  greeter-session=unity
F  xserver-command=X -core
I  autologin-guest=false
I  autologin-user=muru
I  autologin-user-timeout=0

Sources:
A  /usr/share/lightdm/lightdm.conf.d/50-disable-log-backup.conf
B  /usr/share/lightdm/lightdm.conf.d/50-greeter-wrapper.conf
C  /usr/share/lightdm/lightdm.conf.d/50-guest-wrapper.conf
D  /usr/share/lightdm/lightdm.conf.d/50-ubuntu.conf
E  /usr/share/lightdm/lightdm.conf.d/50-unity-greeter.conf
F  /usr/share/lightdm/lightdm.conf.d/50-xserver-command.conf
G  /usr/share/lightdm/lightdm.conf.d/60-lightdm-gtk-greeter.conf
H  /usr/share/lightdm/lightdm.conf.d/95-kylin-greeter.conf
I  /etc/lightdm/lightdm.conf

Note the source of the configuration.


HP-ENVY-x360-Convertible screen flickering with ubuntu 14.04,15.10 and 16

I found a suggestions over at the forums:

Updated Nvidia Drivers - Resulted in Flickering Display

Try these and let me know if it works.


Permission denied (publickey) error right after generating the SSH keys

Detailed instructions how to connect to SSH server can be found here
From your question it is clear that you should do the following:
How To Create SSH Keys
SSH keys should be generated on the computer you wish to log in from. This is usually your local computer.
Enter the following into the command line:
ssh-keygen -t rsa

Press enter to accept the defaults. Your keys will be created at ~/.ssh/id_rsa.pub and ~/.ssh/id_rsa.
have the following files in the ~/.ssh directory in the client machine:
-rw------- 1 demo demo 1679 Sep  9 23:13 id_rsa
-rw-r--r-- 1 demo demo  396 Sep  9 23:13 id_rsa.pub

As you can see, the id_rsa file is readable and writable only to the owner. This is how it should be to keep it secret.
The id_rsa.pub file, however, can be shared and has permissions appropriate for this activity.
On the server side, you should have the the public key (not the private key).


Wireless not Working on Dell Latitude D430

Try this for a for your D430

sudo apt-get update
sudo apt-get install firmware-b43-installer
sudo apt-get remove bcmwl-kernel-source
sudo reboot


Mouse not acting the way it used to on google chrome

I suppose that you have a problem with your mouse. The micro-switches in a mouse are mostly cheap stuff (even in expensive models)
and not properly capsuled. Just a bit of dust or dirt in the micro-switch can lead to not intended double-clicks.
It will happen sometimes or often, sometimes the mouse works without a problem. Try a different mouse to check if the problem persists.

Do you have Chrome Toolbox installed? In the Chrome Toolbox options general tab you can disable Doubleclick on tab to close it.


What you want is to use software that comes with webcam, that can't be done since that software is made for windows (by Logitech decision), not Linux. However there is good software for Linux, for example guvcview:

sudo apt-get install guvcview


How can I play mp4 movie on my ubuntu OS?

This command in a terminal should do:

sudo apt install ubuntu-restricted-extras

(As already explained by David Foerster, but this should be an answer, not a comment.)


Solved. Thanks to user march!!

  The issue with the permissions for /dev/ttyACM0 can be permanantly
  solved by adding yourself to the dialout group. You will have to
  logout and then log back in before the group change is recognized.

  You can do this with sudo usermod -a -G dialout terrik if terrik is
  your username.


No internet connection (DNS server address is Router address)

Many routers do "DNS forwarding", meaning that they advertise themselves (via DHCP) as DNS servers, and then cache and forward any DNS requests from the internal network.

The first thing to ask is whether this only happens on Ubuntu or on another OS (Windows, Mac OS, Android, iOS) as well. From the looks of it, this will happen regardless of the OS, and the cause may be a misconfiguration in the router. So you can do two things:

Configure your router properly. Log into its configuration page (check your manual for this), and configure a static DNS (Google's public DNS is a good choice, use 8.8.8.8, more here). Then have the computer reconfigure its interface via DHCP. You should then be able to properly resolve names.
Configure the DNS address directly on the computer, bypassing the router. Click on the wireless/network icon on the top bar, then select "Edit Connections", grab the connection you're using, click "Edit". Then on the "IPv4 settings" tab, select "Automatic (DHCP) addresses only", and on the (just enabled) DNS Servers field enter 8.8.8.8.

To diagnose which DNS server is resolving your names, open a terminal (ctrl-alt-t) and type dig www.yahoo.com, you should see diagnostic information about where your queries are being sent.


Ubuntu cloud server : hardware requirements

Ubuntu can run commercial cloud services without any issues, provided the application(s) offering the cloud service are properly configured.

One such application is OwnCloud which is quite efficient at its work for heavy usage and can be deployed for commercial/private usage.

Software first:

Ubuntu 16.04 LTS is suggested.
MySQL/MariaDB for database.
apache + php 7 for webserver.
Most recent version of OwnCloud

For hardware requirements :

The system you will need depends on the number of concurrent users trying to access the server. For following list, I assume you have 100 concurrent users accessing. (This answer depends on opinion hence, I am giving answer from my personal experience).

6-10 HDDs (4 or 8 TB each) running in RAID10 configuration
CPU - Intel Xeon processor with >8 cores. (Dual CPU system with two processors is also possible for heavy workloads).
RAM - 32 GB or higher size ECC(error correcting) RAM is preferred.
You don't need GPU.
Motherboard - You need a motherboard which should have at least two
Ethernet ports, and dual socket board if you plan a dual CPU setup.

(Hard disk size depends on your required need.  RAM greater than 32GB and two CPUs on a board are almost essential for commercial setup with heavy workload.)

A few starting points:

High end server Motherboards: Asus, SuperMicro

CPUs: Select CPU based on CPU socket of the board.
Memory : Choose supported memory based on the motherboard.

Configuration

Even with very good hardware, poorly configured software will make the server fail. Hence, the tricky part is how well is the components of OwnCloud optimized for workload.

Some things to consider while setting up :

Concurrent connections allowed in apache
apache timeout duration should be appropriate.
Concurrent php connections per page served.
Max size of file transfers  in php.
Max number of database connections.
Optimization in tables of database may be needed (optimization of InnoDB tables and DB parameters)
Owncloud - Memory Caching should be used (APC/APCu on Ubuntu is preferred)
Owncloud - Cache directory location should be on a fast drive(maybe MLC or SLC based SSDs)
Use SSL for security (necessary for commercial work).

Check these link for details and more:
OwnCloud- pre setup optimization ,
OwnCloud server tuning.


I am running Ubuntu 12.04 with two Radeon HD3450 cards on four monitors.

I was able to get things working by choosing Unity2D (not 3D) on login and enabling Xinerama. I have four monitors and it's working well.


Why do I need root privileges to umount a drive at the command line, but not in Nautilus? How to change that?

Nautilus doesn't unmount the device directly; it talks over DBus to a system daemon (udisks-daemon) and asks it to unmount.

The daemon checks if you're allowed to do that, by contacting another system daemon, PolicyKit.

PolicyKit uses the configuration defined in /usr/share/polkit-1/actions/org.freedesktop.udisks.policy (unless the local system administrator overrides it in /etc/polkit-1).  That file tells PolicyKit that users with active console sessions can detatch drives, so PolicyKit talks to a third daemon, ConsoleKit, to see if you have active console sessions.  Logging in via gdm counts as a console session; logging in via ssh doesn't.

There's a command-line tool udisks that lets you unmount devices without using sudo, using the same mechanism:

udisks --unmount /dev/sdb1

that unmounts the filesystem; I can also detatch the whole device with

udisks --detach /dev/sdb

which makes the LED on my USB key go dark.


Upgraded to 19.10 and network is unclaimed

I solved it by going to realteks website and download the latest driver and manually installed it. now im online ...yuhu.


Add an SSH option to an sftp URL in nautilus

You could create ~/.ssh/config with an appropriate config entry for your host like so:

Protocol 2
Host yourhost
    User youruser
    Hostname your.host.address
    GSSAPIAuthentication no
    Port 1234

For more options, consult man ssh_config


Ubuntu 17.10 doesn't see my wi-fi network after reboot

It helped me to re-install the Broadcom driver by this article.
Basic steps:

Remove an existing package:
sudo apt-get purge bcmwl-kernel-source
Update cache:
sudo apt-get update
Update PCI.ID lists:
sudo update-pciids
Install b43-installer:
sudo apt-get install firmware-b43-installer
Reboot your system

ADDED
I have switched a Wi-Fi channel on my router to 6th from 12th.


How to perform an emergency shutdown without sudo?

My opinion is to change your lines into something like this in your script:

echo 1 | sudo tee /proc/sys/kernel/sysrq > /dev/null
echo o | sudo tee /proc/sysrq-trigger > /dev/null

And give the specific user access to run tee command with these arguments without the need of entering password, something like:

username ALL=(root:root) NOPASSWD: /usr/bin/tee /proc/sys/kernel/sysrq

Remember that it's not possible to redirect an string into a file which needs a specific permission using >, it means something like:

sudo echo hi > file
echo hi sudo >  file

is not going to work.

At the same time you can't simply change the owner of these files, cause /proc is a virtual file system managed by Kernel.


No and Yes. If your PC overheats, the first thing you need do is to clean the Heat Sink. Then check the Drivers. If you have Nvidia GFX card Ubuntu will run fine.

You can download an ISO, Burn that to a DVD or install that into a Pen Drive, and then Boot into a Live Session. Make a through test how your system performs, if everything goes well, then Install it either along side Windows or Overwrite Windows.

Check this Link - http://www.ubuntu.com/download/desktop/install-desktop-latest


How to print using only color cartridge WHEN OUT OF BLACK INK?

Open Printer utility, right click on your printer and select properties, select printer options in the left pane, scroll down printer features common in the right pane and select color option in the ink set and select apply. Hope it helps.


Import media doesn't set the artist and album for all my tracks

If you have such a huge audio collection and want to tag them all, so they are recognised by Banshee, your tool of choice may be easytag . It is very powerful and intuitive.


How to share desktop to an additional monitor

You can enable the dual monitor from the Ubuntu display preferences as explained below.

Open Displays which will display the following window.

Make sure following are taken care in this window:

If you see only one monitor, click on Detect Monitor, which should detect all the monitors connected to the Ubuntu laptop or desktop.
Uncheck Mirror Screens check-box as shown above. When you have this enabled, both the monitors will show the same display, which you don’t want.
Highlight the first monitor and click the ‘On’ radio button. The first monitor will already be in on state.
Highlight the second monitor and click the ‘On’ radio button.
Select the Show displays in panel check-box, which will display the icon to configure the display on the top right hand panel for easy access.
To change the display order of the monitors, simply drag the monitor to re-arrange them accordingly

Source: http://www.thegeekstuff.com/2009/08/ubuntu-tips-how-to-setup-dual-monitor/


Best filesystem for a shared data space?

You can find a comparsion between those two here

I would personally use NTFS over FAT because of better error recovery. FAT is old technology.


Krusader window too wide - can't be changed

While opened Krusader you can try keyboard combinations for window manipulation:

Alt+F8 (for window resize);
Alt+F10 (to maximize/unmaximize its window).

Or move Krusader's configuration file with

mv ~/.kde/share/config/krusaderrc ~/krusaderrc_old

and then relaunch Krusader. It should reset to default settings.


How to install indicator Netspeed in Ubuntu 16.10?

Have you considered try Indicator Netspeed Unity ? It was a fork of mgedmin's  Netspeed Indicator. Despite its name, it should work with any panel that supports AppIndicators.

Quote from Webupd8 article.

  Indicator Netspeed Unity is a heavily modified Indicator Netspeed, which adds the following extra features:

  four panel display modes: download, upload or total (either merged or separated) network speed;
  configurable bit rate prefix;
  shows total downloaded and uploaded data for the current session in the indicator menu ("All" item);
  enable/disable padding - when enabled, it preserves the indentation    of indicator text (I recommend disabling this or else you'll end up
  with a gap between the icons and text);
  supports using custom icons (available via Dconf);
  added a settings menu which allows changing the upload/download prefix, change the theme to dark/light or current (system) theme and
  run nethogs for a more detailed analysis.

How to install ?

You can either use apt-get install command by adding ppa first.

sudo apt-add-repository ppa:fixnix/netspeed
sudo apt-get update
sudo apt-get install indicator-netspeed-unity

Otherwise, you can install from the .deb files

32 Bit

wget http://ppa.launchpad.net/fixnix/netspeed/ubuntu/pool/main/i/indicator-netspeed-unity/indicator-netspeed-unity_1.04-yakkety0_i386.deb
sudo dpkg -i indicator-netspeed-unity_1.04-yakkety0_i386.deb

64 Bit

wget http://ppa.launchpad.net/fixnix/netspeed/ubuntu/pool/main/i/indicator-netspeed-unity/indicator-netspeed-unity_1.04-yakkety0_amd64.deb
sudo dpkg -i indicator-netspeed-unity_1.04-yakkety0_amd64.deb


Deleting the access.log file or removing its contents in Ubuntu server


Error: libpulsecommon-4.0.so: No such file or directory

open your terminal and type as

sudo apt-get install --reinstall libpulse0

then try again with logout/restart.


ubuntu 18.04 - 4.15 kernel didn't show up even after grub-update

Have you tried to reboot after you have upgraded from 17.10? If you're using 17.10 sure you will get 4.13 kernel from uname -r

The update process looks like this:

You boot with 17.10 (kernel 4.13)
You upgrade your system to 18.04, got everything installed even the 4.15 kernel, you can check them with command dpkg -l | grep '\-4.15.0\-' (But you're still running 4.13 kernel now)
Since you have your system upgraded from Artful to Bionic, the package source list will change, this may explain why you can't get 4.13 header packages anymore.
Once you reboot your system, you should be boot with Bionic and 4.15 kernel.

Last but not least, try not to pull off the rock that you're standing right on it. i.e. remove the kernel that you're running.

If you want to remove a certain kernel, it's better boot to another kernel  first (either doing this on boot or use a tool like grub_selector, grub customizer) to avoid unexpected hassles.


There are several ways to do this. (Disclaimer: all this methods can only make the folders show the amount of items that they contain, not their actual size)

Probabliy the most used option is to use the "List View" mode. You can enable it by going to View menu and click on List. You get this:

But there's also a really comfortable method to do it, which allows you to navigate your folders  using the "Icons View". All you have to do is going to Edit menu, click on Preferences option and then click on the Display tab. After that you have to set the first zooming option to show you the size of your folders and files.


Can you change the update interval for the hardware-monitor applet?

The hardware monitor applet gets its data from lm-sensors, the data is taken raw from the system and lm-sensors does not limit the amount of times it collects this information so unless you are good at programming and want to help the hardware monitor team add the function your best bet at the moment would be to create a script to switch on and off the lm-sensors service at regular intervals to dictate how often the data is sent to the applet.

Hope this helps.


Ok I found the solution. First, it looks like it is necessary to install libsecret-tools because there is no CLI command to access the gnome keyring using gnome-keyring (is that true? looks strange to me).

Then you can setup a password with:

secret-tool store --label=Unlocker type unlock-keyring

And call that password with:

secret-tool lookup type unlock-keyring

You will be prompted then, to enter the keyrings password and it will be unlocked.

Of course, you don't need to setup an extra "Unlock" password, thats a bit nonsense because its just used to force the keyring to unlock. You can also choose any of your existing passwords to unlock the keyring, but I liked it more this way.

For more infos about using secret-tools you can lookup this question as well: Is it possible to use secret-tool to lookup existing seahorse passwords?

If there is another solution without installing an extra secret-tool, I would like to hear that!


Trackpoint configuration is reset after boot in ubuntu 15.04

Ok found the solution, by looking at the source of the program the directory where the files are stored is the following in my case:

/sys/devices/platform/i8042/serio1/serio2/

And in this dir different configuration files with integer values can be found so the only thing that needs to be done is

echo xx | sudo tee /sys/devices/platform/i8042/serio1/serio2/speed
echo xx | sudo tee /sys/devices/platform/i8042/serio1/serio2/sensitivity

whereas xx needs to be between 0 and 250 (when its 0 the trackpoint does not work.

Here is a link for more explanation link


Upgrading to mainline kernel 5.9 with ZFS (on 20.10)

I noticed that, while the version of the ZFS packages in the Ubuntu development version (hirsute) is currently 0.8.4-1ubuntu13, the changelog shows the following:

Changelog
zfs-linux (0.8.4-1ubuntu13) hirsute; urgency=medium

  * Add Linux 5.9 compat fixes (LP: #1899826)
    - 4800-Linux-5.9-compat-add-linux-blkdev.h-include.patch
      include blkdev.h in various sources
    - 4801-Linux-5.9-compat-NR_SLAB_RECLAIMABLE.patch
      deprecate some older page free stats for arc free page calculation
    - 4802-Linux-5.9-compat-make_request_fn-replaced-with-submi.patch
      API change for block allocation
    - 4805-Increase-Supported-Linux-Kernel-to-5.9.patch
      allows driver to be built against 5.9
  * Add Linux 5.10 compat fixes
    - 4710-Use-percpu_counter-for-obj_alloc-counter-of-Linux-ba.patch
      prerequisite for 4804-Linux-5.10-compat-frame.h-renamed-objtool.h.patch
    - 4720-Linux-5.7-compat-Include-linux-sched.h-in-spl-sys-mu.patch
      prerequisite for next set of patches
    - 4804-Linux-5.10-compat-frame.h-renamed-objtool.h.patch
      rename check of linux/frame.h to linux/frame.h
    - 4805-Linux-5.10-compat-percpu_ref-added-data-member.patch
      API check to the percpu_ref structure
    - 4806-Linux-5.10-compat-check_disk_change-removed.patch
      check_disk_change removed, functionality moved to zfs_check_media_change
    - 4807-Linux-5.10-compat-revalidate_disk_size-added.patch
      use revalidate_disk_size where necessary

 -- Colin Ian King <colin.king@canonical.com>  Tue, 3 Nov 2020 12:22:22 +0000

which indicates that the required changes for compatibility with newer Linux kernels have been backported to these packages. So I installed the zfs-dkms package from the hirsute repositories, which gave me a working DKMS ZFS module with my mainline kernel.


No Sound after playing around with pulseaudio

To get pulseaudio back and running you can run the command pulseaudio --start or by using the Alt+F2 combo for running commands via the dash, just type pulseaudio and you'll get a result that'll get it running.


You have to install gnome-panel package which comes up with ability to create a application launcher on the desktop or wherever you like. Add --no-install-recommends suffix to prevent other package that aren't necessary.

sudo apt-get install --no-install-recommends gnome-panel

After installing gnome-panel, use following command to create a launcher.

gnome-desktop-item-edit --create-new ~/Desktop

Once you execute the above command, create launcher application will be opened.

In Type field "Application" will be a default value. If you're creating launcher for application which has no gui, that runs in terminal like VIM editor then you need to select "Application in Terminal".
In Name field type application name.
In Command field type the executable command which open your application.
Comment field is optional.

To set icon, click on the small box on the top left side near name field and choose a image for it. Click "OK" if you are done.


Thunderbird Lightning: How to edit categories?

In more recent versions of Thunderbird, the settings for the calendar categories can be found under Edit- Preferences, Calendar tab, Categories. The settings may also be reached from Tools - Add-on preferences - Lightning.

(with thanks to flawr for the screenshot!)


cryptsetup luksAddKey throwing 'Maximum keyfile size exceeded' error - fix? 14.04

It sounds like the key file that you are trying to use is at least 8 KiB, which exceeds cryptsetup's default maximum size. You can use the --new-keyfile-size <size_in_bytes> option to force cryptsetup to use the key, but I recommend using a random key with a smaller size, because a key that is larger than the master key of the LUKS volume offers no additional security over a key that is the same size as the master key (as long as the key material is truly random).

The maximum master key size for LUKS is 512 bits, but it can also be 256 bits. You can check the size of your master key by finding the size of "MK bits" in sudo cryptsetup luksDump /dev/<device>.

I suggest generating keys from /dev/random. For example, to generate a random 512-bit (64-byte) key:

head -c 64 /dev/random > luks_key


How to integrate Rhythmbox to play Internet Radio?

searching for radio-stations
The default Rhythmbox URL based radio-station capability is limited - you have to research the internet radio-station - and then find what the actual URL it uses to play the radio-stream.
Fortunately - there is another way
disclaimer - I'm the author of this plugin
The RadioBrowser plugin could be useful if you like to browse for new radio stations.
You mentioned Jazz...

There are several jazz radio-stations as shown in the picture.
More information in the links below
installation instructions
sudo add-apt-repository ppa:fossfreedom/rhythmbox-plugins
sudo apt-get update
sudo apt-get install rhythmbox-plugin-radio-browser

then start rhythmbox and select the menu edit-plugins, tick the checkbox internet radio station browser

Useful Links:

Recording the radio streaming of Radiotray or Rhythmbox
How do I install third-party rhythmbox plugins?


According to the cloud-init docs the way to disable it is:

sudo touch /etc/cloud/cloud-init.disabled

And/or set cloud-init=disabled on the kernel command line if it's enabled that way.


Like "PerfMon" in Windows do we have something similar in Ubuntu?

Sysstat is your friend, assuming you are fine with using the command line. Have a look for examples here for memory usage, and here for cpu usage.


List only local user accounts with a single command

If you want the list of users that can actually log into the machine, look for the users whose login shell (the last field in /etc/passwd) is not set to /bin/false or /sbin/nologin:

$ awk -F: '$NF!~/\/false$/ && $NF!~/\/nologin$/' /etc/passwd
root:x:0:0:root:/root:/bin/bash
sync:x:4:65534:sync:/bin:/bin/sync
terdon:x:1000:1000::/home/terdon:/bin/bash
git:x:996:996:git daemon user:/:/bin/bash
bib:x:1001:1001::/home/bib:/bin/bash
bob:x:1002:1002::/home/bob:/bin/bash

And to get the user name only:

$ awk -F: '$NF!~/\/false$/ && $NF!~/\/nologin$/{print $1}' /etc/passwd
root
sync
terdon
git
bib
bob

If you want only "normal" users, those who were created using the standard approach and therefore will have a home directory under /home, use:

$ awk -F: '$6~/\/home/' /etc/passwd
syslog:x:101:104::/home/syslog:/bin/false
terdon:x:1000:1000::/home/terdon:/bin/bash
bib:x:1001:1001::/home/bib:/bin/bash
bob:x:1002:1002::/home/bob:/bin/bash

And, for the username only:

$ awk -F: '$6~/\/home/{print $1}' /etc/passwd
syslog
terdon
bib
bob

Finally, you can combine the two to get all users with a home in /home and a valid login shell:

$ awk -F: '$NF!~/\/false$/ && $NF!~/\/nologin$/ && $6~/\/home/{print $1}' /etc/passwd
terdon
bib
bob

On a sane Ubuntu system, all of the non-system users should have a user ID between 1000 and 29999. So, assuming you haven't created any user with a lower UID, you could do:

awk -F: '$3>999 && $3<30000{print $1}' /etc/passwd

And you could combine everything again (some services have regular user IDs but don't have a login shell, jira on my work server, for instance):

awk -F: '$3>999 && $3<30000 && $NF!~/\/false$/ && $NF!~/\/nologin$/ && $6~/\/home/{print $1}' /etc/passwd


Bash script not adding variables to session

In your .bashrc reference your custom startup script using . setup.sh instead of ./setup.sh. That will cause it to be executed in the context of the current session instead of being executed as a separate program with its own context.


Not being able to change permission of home folder from root to

The FAT32 filesystem doesn't support attributes like ownership and have the owner set with the mount options.

You need to format the partition with an advanced filesystem like ext, btrfs or ntfs, although I'd avoid the latter.

See https://askubuntu.com/a/96929/6161 on how to remount using different permissions.


How can I install the older gnome control center in 11.10?

I'm afraid this isn't easily possible because of 11.10's move to GNOME 3. (It's far easier just to stay with 11.04, if that's what you want!)


How to install latest version of rgedit in 13.04

From the README file on sourceforge:

To install, extract the RgeditXX.tar.bz2 archive somewhere and, depending on your
gedit's major version, copy the contents of the resulting folder into to your
 ~/.gnome2/gedit/plugins folder for gedit2, and ~/.local/share/gedit/plugins for gedit3. That folder should now contain:

RCtrl (this is a folder)
RCtrl.gedit-plugin
RCtrl.py
ReadMe.txt (this ReadMe.txt file)

If you installed the older verison through the software center, I'd recommend uninstalling it the same way before doing the above.


Guake terminal showing up wrong in Unity

As a work-around, you can adjust the Guake terminal width to less then 100% of the screen width.

Make a backup of /usr/lib/guake/guake.py for Ubuntu 12.04 and for Ubuntu 12.10 and newer, backup /usr/bin/guake file.
Open a terminal and run the following command:

For Ubuntu 12.04:

sudo -i
gedit /usr/lib/guake/guake.py
exit

For Ubuntu 12.10 (or newer) Guake versions, use the following command instead:

sudo -i
gedit /usr/bin/guake
exit

Then scroll down to somewhere around line 780-820 which says width = 100 - this is how it looks like:

screen = self.window.get_screen()
height = self.client.get_int(KEY('/general/window_height'))
width = 100
halignment = self.client.get_int(KEY('/general/window_halignment'))

And modify the width value (percentage) to whatever you want. Save the file, restart Guake and that's it.

Reference: WepUp8 Article


Install the ntfs utilities with ...

sudo apt-get install ntfsprogs

Then do a ...

sudo ntfsfix /dev/sdb2

If that does not repair your disk you need to start looking for Windows tools.


How to add the Windows Classic Theme to Ubuntu 16.04.1?

First, open the terminal with ctrl + alt + t and download the file to your home directory.

wget https://github.com/Elbullazul/Redmond-Themes/releases/download/2016%2F11%2F15/Windows.9x.R4.zip

Alternatively, move the file you already downloaded to your home directory.

Now unzip the file.

unzip Windows.9x.R4.zip

Finally move the theme folder to your themes directory.

sudo mv Windows\ 9x /usr/share/themes/

This should make it visible under the themes section of the settings app