how to display network manager icon on xfce panel

For the benefit of further readers having the same problem I would like to note that I managed to get the indicators to show up in the xfce4 indicator area without using the indicator plugin.

I fiddled with the settings, but I think the key point was to deactivate the gnome indicators that I marked with red in the screen shot. I reckon these are gnomish programs that might indeed need the indicator-plugin. As can be seen at the top right of the screen shot, at least the network manager and the power indicator appear. Whether there is something special for bluetooth in xfce4, I don't know.


how to formulate a timeshift CLI backup command to an external drive

man timeshift is your friend. It includes the answer to your question.
‐‐snapshot‐device <device> Specify backup device (default: config)


Partition table lost - how to recover lost LUKS partition, I have some backup partitioning data

To recreate the original partition scheme you will need to run a partitioning tool and create each partition with the start and end sectors from the backup data. That should restore the MBR exactly as it was. Try sfdisk:

sfdisk /dev/sdb -uM << EOF
2,114828,52
114830,19074,0
133904,585938,255
719842,1187896,7

You should check this for yourself. Each line is start,size,id with size in megabytes (-uM) based on your old partition data:

Start:        2048 End:   117585919 Size:   117583872 FsId: 52 Label:                      ClusterSize:   8 FreeSectors:   109144672 Primary: 1 Bootable: 0 BootVolume: 0 SystemVolume: 0
Start:   117585920 End:   137117695 Size:    19531776 FsId:  0 Label:                      ClusterSize:   1 FreeSectors:    19531776 Primary: 0 Bootable: 0 BootVolume: 0 SystemVolume: 0
Start:   137117696 End:   737118207 Size:   600000512 FsId: 255 Label:                      ClusterSize:  -1 FreeSectors:           0 Primary: 1 Bootable: 0 BootVolume: 0 SystemVolume: 0
Start:   737118208 End:  1953523711 Size:  1216405504 FsId:  7 Label:           Data-Drive ClusterSize:   8 FreeSectors:  1002478672 Primary: 1 Bootable: 0 BootVolume: 0 SystemVolume: 0

If you can not get the partition table recreated, have a look at this thread on recovering LUKS partitions.


External display on Vortex III laptop with Ivy Bridge and NVIDIA GTX 675M

Answering myself... I eventually bought this laptop and can confirm that DVI output works out of the box without using the dedicated GeForce GPU. According to the pcspecialist support, HDMI will work as well but I was not able to test it since I do not have any HDMI capable monitor.

EDIT: So I did test HDMI in the end, and it works okay without the dedicated GPU.


How can I install sudo without using su?

Boot up the machine, and after the BIOS screen, hold down the left Shift key. You will then be prompted by a menu that looks something like this:

If instead you get options like:

You need to go to Advanced Options using arrow keys and hit Enter and then choose the recovery mode

Hit the down arrow until you select the 2nd entry from the top (the one with the recovery mode in the description) and then hit Enter.

Now you should see this menu:

Using the arrow keys scroll down to network and hit Enter to enable networking. If asked to remount the partition, hit Enter on yes.

And then go to root in the same menu and then hit Enter.

You should now see a root prompt, something like this:

root@gijs-pc:~#

At this stage you might have a read-only filesystem. You have to remount it with write permissions:

mount -o remount,rw /

now, install sudo by:

apt install sudo

check your sudo settings once again by:

visudo

also, check if your account gijs is a member of sudo
If not, add him as a member of sudo and wheel group by:

usermod -aG sudo gijs
usermod -aG wheel gijs

Now, you may restart and you now should have access to sudo.

This answer is abridged version of Jorge Castro's answer on How do I reset a lost administrative password?


Recover accidently deleted eclipse ini File

Just remove the file. A new one with the default settings will probably be created the next time your run Eclipse. To be on the safe side, just make a copy of it:

mv /path/to/eclipse.ini ~/eclipse.ini.backup

Then, run eclipse again and everything should be back to normal.


How can I view the source code of the actual package version online?

TL;DR

If you see links with anonscm.debian.org or git.debian.org then visit Debian Salsa GitLab repositories and the search for the package here.

Bugs

Three bugs related to this problem exist:

Bug of the https://packages.ubuntu.com , it should not show dead links with anonscm.debian.org and git.debian.org - I reported it to launchpad as bug 1812562;
Bug of apt-get - it should not show broken links with anonscm.debian.org - I reported it to launchpad as bug 1812564;
Bug of apt-get - it should not show broken links with * http://git.debian.org* - I reported it to launchpad as bug 1812577.

Solution

The svn://anonscm.debian.org is down after Ubuntu 16.04 LTS (and 14.04 LTS) release, so one should use its successor - Debian Salsa GitLab repositories then search for needed package here (or visit source package page for newer bionic release on packages.ubuntu.com).

As the result one can get the correct URLs for the source package:

  Debian Package Source Repository (VCS: Git)
    * https://salsa.debian.org/python-team/applications/bleachbit.git
  Debian Package Source Repository (Browsable)
    * https://salsa.debian.org/python-team/applications/bleachbit

Here one can switch to the needed version branch (1.10-1 in this case):

  https://salsa.debian.org/python-team/applications/bleachbit/tree/debian/1.10-1

and view any needed source code file.


Compare installed deb package with deb file

Debsums:
http://manpages.ubuntu.com/manpages/oneiric/man1/debsums.1.html

  NAME
  debsums - check the MD5 sums of installed Debian packages

  DESCRIPTION
  Verify  installed  Debian package files against MD5
  checksum lists from /var/lib/dpkg/info/*.md5sums.

  debsums can generate checksum lists from deb archives
  for packages that don't include one.


Convert all audio files to low quality in Ubuntu

Here's a way to find all of your mp3 files which are over your specified bitrate and convert them to a lower bitrate.  Be sure to read all the way to the end before starting, because there are two options for the actual transcoding: Clementine or script.

You'll need to install some packages:

sudo aptitude install mp3info clementine lame gawk findutils

To make a list of all your music files and their bitrates, execute the following after you replace /path/to/your/music appropriately:

find /path/to/your/music -iname '*.mp3' -print0 | xargs -0 mp3info -rm -p '%r:%F\n' > transcode.kbps

Look at the file transcode.kbps and make sure it looks something like this (bitrate:filename):

128:/path/to/your/music/dir1/file.mp3
256:/path/to/your/music/dirX/fileX.mp3
320:/path/to/your/music/dirY/fileA.mp3

When that looks good execute this awk command, to create a playlist containing only the files higher than a specified bitrate (here all files with bitrate > 160 will be put into the m3u playlist):

awk -F: '$1 > 160 { print $2; }' transcode.kbps > transcode.m3u

Check the file transcode.m3u and make sure it looks OK.  When it's good, your ready to transcode!

Clementine Transcode Solution

On the Playlist menu, select "Load Playlist" and open transcode.m3u.
Click in the list of your files and type CTRL-A to select all files in the playlist.
Right-click on the playlist and select the context-menu item "Add file(s) to transcoder."
Set your desired parameters in the Transcoder window, remember to set the options. Probably you want something like "Optimize for bitrate 128kbps, constant bitrate, standard quality".
Click "Start Transcoding"

Wait for your transcoding to finish.

The main problem with using Clementine at least on Ubuntu 10.04 Trusty with Clementine 1.2, the only option is to create a new file alongside the old file.  I think if you have a music player connected, Clementine would let you transcode directly to the music player.

Since the files you want to convert are already on the music player, that presents a problem, because the new files may fill up your player.

Script Transcode Solution

It's a fairly trivial script to process the transcode.m3u with lame to transcode the files and remove the old files as it goes.  Save this into a file named transcode.sh:

#!/bin/sh -e
# transcode.sh -- read filenames from standard input and transcode files
while read file
do
    if lame -h "$file" "$file.new"
    then
            mv "$file.new" "$file"
    else
            rm -f "$file.new"
    fi
done

Now you can execute:

sh transcode.sh < transcode.m3u

and the script will transcode all the files, deleting the old file each time after the new one is successfully created by lame.

You can edit the lame command parameters in the transcode.sh script to do any other transcoding parameters you like.


Synaptic package Manager Broken packages

Broken packages that was not shown on synaptic are viewed and purged through the terminal,

If you want to view the broken packages,then run this command

dpkg -l | grep ^rc | awk '{ print $2 }'

If you want to remove the broken packages,then run this

sudo apt-get purge $(dpkg -l | grep ^rc | awk '{ print $2 }')


MacBook Pro 2016 with Touch Bar - Dual-Booting Ubuntu

I didn't try it myself but I did some online research nonetheless. In its current state it appears to be impossible to run Ubuntu (or any Linux) on a Macbook Pro 2016 in a useful way.

Apple's 2016 MacBook Pro & Linux Don't Mix (Phoronix)
“2016 MacBook Pro Is Incompatible With Linux” (FOSSbytes.org)
Warning: 2016 MacBook Pro is not compatible with Linux (Reddit thread that serves as the source for the above article)

Money quote:

  I have a $2800 disappointment.

(Pun intended.)

I'll try to address the main blocking issues mentioned in these posts and articles, what needs to be done to get around them and how likely it is to see a solution any time soon:

Intel graphics: Looks like some reverse-engineering will be necessary before the drivers play nicely with this otherwise supported graphics chipset …probably some proprietary Apple EFI BIOS firmware stuff. It's hard to say how soon that will happen. In the mean time there's no hardware acceleration.
AMD graphics: AMD GPU support on Linux has been a mess since the deprecation of the Catalyst drivers but it looks like AMD is actively seeking to improve the situation and I hear that the open-source drivers are in an alright shape once support for a new chipset has been added.
Keyboard and touchpad: Like with previous Macbooks, we'll have to wait until someone figures out how they work and writes a driver for them. I'd expect considerable interest in such a driver and it looks to be similar to existing drivers for previous Macbooks, so we'll probably see something within a few months.
Internal SSD: The Reddit thread author reports a bogus PCI device class flag for the internal SSD while Michael from Phoronix doesn't, so this appears to be something that only affects some new Macbooks (e. g. because Apple didn't use the same model for all of them). To resolve this issue requires either

a firmware upgrade from Apple or the SSD manufacturer and I don't see that happening because the issue doesn't occur in MacOS or Windows, or
a special case handling in the driver in the kernel which probably requires a smallish patch that can be back-ported easily to older (but not too old) kernels.


PXE based installation always sets hostname as 'kickseed'

This issue was due the reverse lookup failure. After resolving this the issue was resolved.


When clicking below window title bar in KDE, window dragging is initiated. Can I change this behavior?

Check your "Window Behavior" settings. System Settings > Window Behavior icon > Window Behavior tab.

1) Try changing the Titlebar Actions to Activate & Raise (if it's not that already) for Inactive windows
2) You may also want to change the Window Actions tab > Inactive Inner Window > Left Button behavior


Go to Unity dash and search for Software Sources

Go to Other Software and select the desired PPA to be removed.
Click Remove


Weird error when launching VLC from command line

This may be a bad idea. Things might go from bad to worse.

You can try doing a sudo apt-get purge libqt*

It will ask you to confirm packages to remove under 'The following packages will be REMOVED:'. Copy those packages in a text file somewhere because we will re-install them again. Confirm and remove them.

Next run a sudo apt-get clean and sudo apt-get autoremove.

Then go to your /home/.config folder and delete the vlc folder in there.

Then reinstall the core packages like ubuntu-desktop, totem and vlc and see whether it will work this time.

I tried this (I didn't confirm though) and the packages that were to be removed included: unity-2d, vlc, skype, qbittorrent, totem, ubuntu-desktop, speedcrunch and alot of qt plugins.


Use "Site Manager" of FileZilla. In Advanced Tab set "Default remote directory" for each site. Reference: wiki.filezilla-project.org/Site_Manager#Advanced_tab
That makes FileZilla cd change directory after login to the default of vsftpd. Like in this post.


Syntax error in for loop when redirecting output to file in background

You should place the background command in () like this:

for k in {2..3}; do for i in {1..3}; do for j in {1..3}; do (./run_parser.sh ${k} ${i} ${j} > parse_${k}${i}${j}.log 2>&1 &); done; done; done


As root:

cd /etc/xrdp
cp km-041d.ini km-040b.ini

This copies Swedish keyboard layout to Finnish keyboard layout.

Now run in your actual X session (not xrdp):

setxkbmap -layout fi

Then connect to this machine via Windows RDP client and Finnish keyboard layout works.


How to increase speed of ubuntu 14.10 32bit?

That will not be possible. It will be slow whatever: the 'recommended' requirements state a dual core with 1Gb.

I would suggest installing another version of Ubuntu: lUbuntu or xUbuntu. Those are lightweight and will get you a better experience.

lUbuntu can be found here and uses the LXDE desktop
xUbuntu can be found here and uses the XFCE desktop


How to start another user session from CLI on SDDM?

There's couple of ways of via command-line

dm-tool switch-to-greeter
qdbus --system org.freedesktop.DisplayManager /org/freedesktop/DisplayManager/Seat0 org.freedesktop.DisplayManager.Seat.SwitchToGreeter
qdbus org.gnome.ScreenSaver  /org/gnome/ScreenSaver org.gnome.ScreenSaver.Lock

Any of these will lock your openbox session and switch you to login screen (except the last one, you have to press arrow to return to greeter as well) where you can  switch the user


Problem using wget to download an entire website

If you want to use wget, you can use the mirror setting to make an offline copy of a website, although some websites might prevent it with their robots.txt settings that stops automated spidering. I have always had a few problems with wget (see my other suggestion below), but the following command does work for many sites. However, be aware that the addition of the -H switch allows it to access all links that are on other sites and to save those also. This command switch can obviously be removed if it is not required.

 wget --wait 1 -x -H -mk http://site.to.mirror/

The command to wait allows some gaps between wget's requests so that the site is not overwhelmed, and the -x command switch specifies that the site's directory structure should be exactly mirrored in a folder in your home folder. The -m switch obviously stands for mirror mode, which allows wget to download recursively through the site; and the -k switch means that after download the files referenced will be those in your mirror directory in your home folder and not those back at the site itself.

After man wget, perhaps the best listing and detailed explanation of wget commands is here.

If wget is unsuccessful and you can't grab as much as you want, I should try the command line program httrack or its web interface, webhttrack, which are available in the repositories. There are a large amount of options for this program, but it is better for downloading whole websites or parts of websites than wget. Webhttrack gives you a wizard to follow for downloading a site (it opens in your browser) as the screenshot below shows.


Malformed Address '10.10.21.08/24', must be X.X.X.X/NN or

The error code indicates that there is a "Malformed Address" in "10.10.21.08/24".

Try leaving out the leading zero in the fourth octet (i.e. write '10.10.21.8/24').


Adding Ubuntu 12.10 windows management feature to Ubuntu 12.04?

You would need to upgrade Unity and Compiz to the Quantal versions —which are very different internally from Precise versions—, but it’s a risky process and I don’t think it’s worth the hassle TBH.


Instead of clicking the icon, right click on the file in the Download folder and after installing wine , there should be an option that says "Open With Wine Windows Program Loader."

It worked for me, I am doing the same, downloading iTunes for Ubuntu.


This is a wrong place to get the drivers. That bundle does not have a required plugin.

Get the drivers HERE

Enter the model name and you will get the correct bundle.


Can't access shell variable in crontab configuration

This is a limitation of the cron daemon. See this from the manpage of crontab:

  The value string is not parsed for environmental substitutions or
  replacement of variables, thus lines like:

     PATH = $HOME/bin:$PATH

  will not work as you might expect.

You can do a workaround, since bash treats the tilde (~) as substitution of $HOME. Therefore use:

JOBS_PATH=~/cronjobs


/usr/local/bin/python3: No module named pip Error on or near line 85; exiting with status 1

Because you have python3-pip package installed, you need to invoke that as pip3:

pip3 list
sudo pip3 install virtualenv


Look like fsck.ext4 saved my day. Although it spammed my terminal, i got my drive fixed.


This will output the serial number of the disk, which should be printed on its label:

sudo hdparm -i /dev/sdc


I managed to fix the error, was basically install resolvconf again and restart the computer. That means this problem has been solved!

How I did this:

Downloaded the .deb file of resolvconf. Link: http://archive.ubuntu.com/ubuntu/pool/universe/r/resolvconf/resolvconf_1.79ubuntu8_all.deb
Installed the .deb file of resolvconf on terminal. Command: dpkg -i <file location>
Started resolvconf with systemctl. Command: systemctl start resolvconf
Rebooted the computer.
WiFi is back!


Stop Skype from launching on startup? (Xubuntu)

I had this same issue (and cross-posted this answer). I was able to prevent it from starting automatically by removing skypeforlinux.desktop from ~/.config/autostart/. I'm using lubuntu; the location of your autostart folder may vary. You can find by using:

$ locate skypeforlinux.desktop

You'll really only want to delete the copy in the directory called autostart, otherwise you won't be able to start the app from the icon.

I'm assuming that the next time you actually, intentionally run Skype (I hope, for the sake of your sanity, that this day is far in the future) that it will try to put that file back. In which case you might have to delete it again or scour Skype for the setting that will prevent that behavior.


On my system it says:
gpg: keyring '/etc/apt/trusted.gpg.d/qgis-archive.gpg' created
gpg: key F7E06F06199EF2F2: 1 signature not checked due to a missing key
gpg: key F7E06F06199EF2F2: public key "QGIS Archive Automatic Signing Key (2020) <qgis-developer@lists.osgeo.org>" imported
gpg: Total number processed: 1
gpg:               imported: 1
gpg: no ultimately trusted keys found

But with the following lines in my /etc/apt/sources.list:
deb [arch=amd64] https://qgis.org/ubuntu focal main # disabled on upgrade to focal
deb-src https://qgis.org/ubuntu focal main # disabled on upgrade to focal

QGIS installs fine using sudo apt install qgis  giving version 3.14.1


How to lock a IP 10 min after over 3 Failed Login attempts

As Liso commented your best bet is to use Fail2Ban. This can be installed with sudo apt install fail2ban.

Then add the following configuration changes to the file /etc/fail2ban/jail.local:

[sshd]
#Set ban time to 10 minutes
bantime = 60
#Decrease the number of failed login attempts before banning to 3
maxretry=3

Once this configuration is in place restart the service with sudo systemctl restart fail2ban.

Thank you for being diligent and securing your server. This makes the world safer for all of us.

N.B. You might have already done this but please make sure you disable root from logging in over SSH.


Normally, docky's icon is dynamically drawn by the program so that it is colored based on your GTK theme. So, the first thing we need to do is turn that off. Launch the "Run Application" dialog by pressing Alt+F2. Then run gconf-editor from that prompt.

Now browse to /apps/docky-2/Docky/Items/DockyItem/ Select the Hue key and change the setting to 1

Now that docky will use the theme icon directly, you can change the icon in the theme. The theme will be found in /usr/share/icons if it is installed system wide or ~/.icons/ if it is installed locally.

For Faenza, you'll want to replace /usr/share/icons/Faenza/apps/scalable/dock.svg with the icon you want. You'll probably want to use /usr/share/icons/Faenza/places/scalable/distributor-logo-ubuntu.svg Depending on the size of your dock, may also need to replace some of the other sizes as well.

You'll need to restart docky.


I would start with the reports from Ubuntu users and sane's list of supported devices.

If it's supported by sane, it should be supported by Ubuntu, as sane is the backend used for scanning.

Generally, I have good expirience with both Canon scanners and Samsung multifunction printer and scanner. Some scanners require some fiddling, others just work. If you are planning to purchase new hardware, you should probably aim for a scanner that has Complete support in SANE.


How to get via SSH the active DISPLAY for a locally logged-in user?

The command who gives me information about current logged in users, and their VTs and displays right away. All I need to do is find the user I want and parse the output.

who | grep $USER | grep -v tty | grep -v pts/ | cut -d' ' -f2

This will output :0, that's what I needed.


How to remove overlay-scrollbars in Ubuntu 17.10 and 18.04?

The reason why solutions working in older Ubuntu versions do not work anymore are changes in CSS which GTK+ uses for styling and layout.

Put this into your ~/.config/gtk-3.0/gtk.css (create the file, if necessary):

/*************
 * scrollbar *
 *************/

.scrollbar,
scrollbar {
    -GtkScrollbar-has-backward-stepper: 1;
    -GtkScrollbar-has-forward-stepper: 1;
}

scrollbar slider {
    background-color: @scrollbar_track_color;
}

.scrollbar.vertical slider,
scrollbar.vertical slider {
    min-height: 15px;
    min-width: 10px;
}

.scrollbar.horizontal.slider,
scrollbar.horizontal slider {
    min-width: 15px;
    min-height: 10px;
}

.scrollbar.vertical.slider:hover,
scrollbar.vertical:hover slider {
    min-width: 10px;
}

.scrollbar.horizontal.slider:hover,
scrollbar.horizontal:hover slider {
    min-height: 10px;
}

.scrollbar.contents,
scrollbar contents {
    background-color: transparent;
    background-image: none;
    background-size: 0;
    border: none;
    border-radius: 0;
}

.scrollbar.trough,
scrollbar trough {
    background-image: none;
    border: none;
}

.scrollbar:hover:backdrop,
.scrollbar.dragging:backdrop,
scrollbar:hover:backdrop,
scrollbar.dragging:backdrop {
    background-color: alpha(@backdrop_selected_bg_color, 0.5);
}

.scrollbar.vertical:hover:dir(ltr),
.scrollbar.vertical:active:dir(ltr),
scrollbar.vertical:hover:dir(ltr),
scrollbar.vertical:active:dir(ltr) {
    margin-left: 0px;
}

.scrollbar.vertical:hover:dir(rtl),
.scrollbar.vertical:active:dir(rtl),
scrollbar.vertical:hover:dir(rtl),
scrollbar.vertical:active:dir(rtl) {
    margin-right: 0px;
}

.scrollbar.horizontal:hover,
.scrollbar.horizontal:active,
scrollbar.horizontal:hover,
scrollbar.horizontal:active {
    margin-top: 0px;
}

.scrollbar.slider,
scrollbar slider {
    background-color: alpha(@backdrop_filling_bg, 0.75);
    border-radius: 10px;
}

.scrollbar.slider:hover,
.scrollbar.slider:active,
scrollbar slider:hover,
scrollbar slider:active {
    border-radius: 20px;
    margin: 0;
}

.scrollbar.vertical:dir(ltr):not(:hover):not(.dragging),
scrollbar.vertical:dir(ltr):not(:hover):not(.dragging) {
    margin-left: 0px;
}

.scrollbar.vertical:dir(rtl):not(:hover):not(.dragging),
scrollbar.vertical:dir(rtl):not(:hover):not(.dragging) {
    margin-right: 0px;
}

.scrollbar.horizontal:not(:hover):not(.dragging),
scrollbar.horizontal:not(:hover):not(.dragging) {
    margin-top: 0px;
}

.scrollbar.slider:hover,
scrollbar slider:hover {
    background-color: alpha(@backdrop_filling_bg, 0.6);
}

.scrollbar.slider:active,
scrollbar slider:active {
    background-color: @backdrop_filling_bg;
}

.scrollbar.slider:backdrop,
scrollbar slider:backdrop {
    background-color: alpha(@backdrop_filling_bg, 0.75);
}

.scrollbar.slider:hover:backdrop,
scrollbar slider:hover:backdrop {
    background-color: alpha(@backdrop_filling_bg, 0.6);
}

.scrollbar.slider:active:backdrop,
scrollbar slider:active:backdrop {
    background-color: @backdrop_filling_bg;
}

Put the same into /root/.config/gtk-3.0/gtk.css for getting the same scrollbar experience for root applications like Synaptic.

And this prevents the scrollbar from disappearing when you are inactive:

echo "GTK_OVERLAY_SCROLLING=0" >> /etc/environment

For changes to take effect you might need to restart applications resp. log out and in again.

I am not completely satisfied with this solution though because the scrollbars do not look as "professional" as one might expect and because they look different in different applications.
E.g. the steppers look OK in Firefox - the up and down arrows are visible.
In Gnome Terminal and Nautilus they are just some rounded rectangles without arrows (as well as in the application I am developing).

Other applications come with their "own" scrollbars - e.g. Geany. They are completely unaffected by these settings and still look as one would expect from decent scrollbars.
Maybe someone can figure out how to "steal" them from Geany.
Update: In 18.04 Geany does not come with it's own scrollbars anymore but e.g. FBReader and Gimp still do.

However, getting rid of the warping slider still works in the old way:

echo "gtk-primary-button-warps-slider = false" >> /etc/gtk-3.0/settings.ini


The issue is resolved. I added the following line in /etc/network/interfaces:

dns-nameservers 8.8.8.8 8.8.4.4


In KDE Plasma, how can I switch between virtual desktops using Meta + Tab?

The default shortcut for changing the desktop on KDE is ctrl + F1 to F4 or F8 for the grid view.
To change this, you can go to "System Settings" >> "Workspace" >> "Shortcuts" >> "Plasma" and here you can remap "Walk through activities" to something else or disable it

Now you can go to the search bar, type "desktop" and choose "Kwin" from the applications list. On the right you should see a list of shortcuts related to desktop switching. if I was you with just two desktops I would choose the "Switch to next desktop" shortcut, click it, and choose add a custom shortcut, don't forget to apply.

That is it, there are a lot of shortcuts on KDE and it looks quite daunting but  is not too bad once you get it down.


Boot from live cd, do disk checks on the disk, make sure that the disk is healthy, and does not have too many bad blocks/sectors.

If the disk checks out fine, and if the system you have is running at least 11.04 or greater, use the installer, and do an upgrade install.

This will keep all your data safe.  It will simply replace the entire OS, and Grub, running a fresh grub configuration.  It will then re-install any and all downloaded applications, updates, drivers, etc.  This should at least get the system booting again, assuming that the crash was not caused by a damaged driver that was downloaded.  If it was caused by a package being damaged because it was not fully downloaded or installed, this will fix the issue.  If it was caused by some part of the system getting corrupted, then this also should fix that.

According to what you said, you reinstalled grub.  If you were pointing grub 1.0 to the grub 1.5 installed on the root drive, then grub could not execute the OS for some reason, the upgrade install should fix this.
Hope this helps you out.


Running a file with command as service in the background

If it's ok that your terminal needs to be open, the common way would be to append & to your command (as previously mentioned). But I would not recommend that as you won't be able to use the terminal any more (your command will still promt its output).
It's better to forward the output to a file or - if you don't need the output - to "nowhere" by appending > /dev/null > 2>&1 &.
The > /dev/null redirects all output to "nowhere", including errors (2>&1) and the last & executes the command in the background..
Try:

./home/pooldaemon/monero-stratum/build/bin/monero-stratum /home/pooldaemon/monero-stratum/config.json > /dev/null 2>&1 &

I think, there is no way to do it any simpler, but using a daemon would be better. Depends on your requirements...


broadcom 43225 wireless on acer laptop is disabled

broadcom

Its not an ungenerous statement that you are not alone with Broadcom issues.

Ubuntu does try its best by offering you what it thinks is the best driver.

I would advise you should stick with the STA driver offered to you for Natty (11.04) for this wireless card.

acer & kernel diagnosis

For the Natty (11.04) kernel there is a particular issue with Broadcom kernel driver clashing with the acer-wmi kernel module.

To test if you are suffering with this issue, run the following:

rfkill list all

solution

If the output from rfkill list all says it is "acer-wireless: soft blocked: yes" then run the following:

sudo modprobe -r acer-wmi
cd /etc/modprobe.d
sudo vi blacklist.conf

Then add blacklist acer-wmi as a new line at the end of the file.

What this does is hide from the kernel the visibility of the acer-wmi kernel module.  Don't worry too much, this module has now power implications.

When you reboot - your wireless will be correctly recognised.

source


What does this error about the Google chrome stable repository mean?

You are getting this is because your system has 32bit i386 architecture enabled (most amd64 64bit installs do).  And the Google repositories do NOT contain i386 packages.
You can fix this message showing up by editing the apt source definition to be deb [arch=amd64] http://dl.google.com/linux/chrome/deb/ stable main which will suppress the error because it tells the system that this repository ONLY has amd64 packages in it - which means it won't attempt to fetch the 32bit packages data.
Find the file that contains this line by running grep -r 'dl.google.com' /etc/apt/, and find the file path containing this item, you'll get output like this:
$ grep -r 'dl.google.com' /etc/apt/
/etc/apt/sources.list.d/google-chrome.list.save:deb http://dl.google.com/linux/chrome/deb/ stable main #Google Chrome (Stable)
/etc/apt/sources.list.d/google-chrome.list:deb http://dl.google.com/linux/chrome/deb/ stable main #Google Chrome (Stable)

We don't care about any .save files for now.
Whatever that file is that's not the .save file (in my case, /etc/apt/sources.list.d/google-chrome.list), edit it so the contents are as follows:
deb [arch=amd64] http://dl.google.com/linux/chrome/deb/ stable main

Save the file, and apt will now only retrieve amd64 packages.


Okay, so it works for me with the openJDK:

Download the installer from here. I saved it in /home/username

Open a terminal(CtlAltT) and:

chmod +x /home/username/thinkorswim_installer.sh
cd /home/username
./thinkorswim_installer.sh
echo 'select the installation directory of /home/username/thinkorswim'
echo 'select to install an icon to the desktop'
chmod +x /home/username/Desktop/thinkorswim.desktop

That gets you this:

I can confirm that it also runs properly with the openjdk version 1.7 when installed in this way.


How do I make a random amount of an elements in QML

You can dynamically create elements from the code. Check this out:

http://qt-project.org/wiki/QML-Dynamic-Objects


Why does Apache need stop and start (rather than restart) for new PHP version to take effect?

Apache loads the php module (among many other modules) when it starts. apachectl restart - according to description in man apachectl - just sends SIGHUP to the Apache process currently residing in memory, telling it to kill all it's children (or, in case of graceful restart, which is SIGUSR1 instead of SIGHUP, just wait until they finish) and then start over, forking the children again. It does not reload the program binaries again from disk.
If you stop Apache then start it again, all running processes are removed from memory and are again loaded from disk.
There seems to be some semantic inconsistency between meaning of "restart" in apachectl restart command and service apache2 restart command (or whatever the Apache service is called instead of apache2). The latter actually stops and starts the service, while apachectl restart is equivalent of service apache2 reload. Note "reload" instead of "restart".


http://www.iasptk.com/ubuntu/20659-how-to-install-dhcp-server-in-ubuntu-server

1) The vmware network configuration must be set in bridge mode

2) Install DHCP server in ubuntu 12.04

From ubuntu 12.04 ISC DHCP server is a transitional package for dhcp3-server so you have to install the following package

sudo apt-get install isc-dhcp-server

There are two main files /etc/default/isc-dhcp-server and /etc/dhcp/dhcpd.conf which we will need to configure so lets take the first.

Configuration of DHCP server

First you need to configure /etc/default/isc-dhcp-server file so you need to edit the file using the following command

sudo nano /etc/default/isc-dhcp-server

You should see similar to the following

#Defaults for dhcp initscript
#sourced by /etc/init.d/dhcp
#installed at /etc/default/isc-dhcp-server by the maintainer scripts
#
#This is a POSIX shell fragment
#
#On what interfaces should the DHCP server (dhcpd) serve DHCP requests?
#Separate multiple interfaces with spaces, e.g. "eth0 eth1?.
INTERFACES="eth0?

Replace eth0 above with the name of your network interface that you want the server to lease addresses on.

Save and exit the file

Now you need to configure /etc/dhcp/dhcpd.conf file for this edit this file using the following command

sudo nano /etc/dhcp/dhcpd.conf

Once it opens you should see similar to the following

#
#Sample configuration file for ISC dhcpd for Debian
#
#Attention: If /etc/ltsp/dhcpd.conf exists, that will be used as
#configuration file instead of this file.
#
#
#The ddns-updates-style parameter controls whether or not the server will
#attempt to do a DNS update when a lease is confirmed. We default to the
#behavior of the version 2 packages ('none', since DHCP v2 didn't
#have support for DDNS.)
ddns-update-style none;
#option definitions common to all supported networks...
option domain-name-servers ns1.example.org, ns2.example.org;
option domain-name "yourdomainname.com";
default-lease-time 600;
max-lease-time 7200;
#If this DHCP server is the official DHCP server for the local
#network, the authoritative directive should be uncommented.
#authoritative;
#Use this to send dhcp log messages to a different log file (you also
#have to hack syslog.conf to complete the redirection).
log-facility local7;
#No service will be given on this subnet, but declaring it helps the
#DHCP server to understand the network topology.
#subnet10.152.187.0 netmask 255.255.255.0 {
#}
#This is a very basic subnet declaration.
subnet 10.0.0.0 netmask 255.255.255.0 {
range 10.0.0.150 10.0.0.253;
option routers 10.0.0.2;
option subnet-mask 255.255.255.0;
option broadcast-address 10.0.0.254;
option domain-name-servers 10.0.0.1, 10.0.0.2;
option ntp-servers 10.0.0.1;
option netbios-name-servers 10.0.0.1;
option netbios-node-type 8;
}
#option routers rtr-239-0-1.example.org, rtr-239-0-2.example.org;
#}
#This declaration allows BOOTP clients to get dynamic addresses,
#which we don't really recommend.
#subnet 10.254.239.32 netmask 255.255.255.224 {
#range dynamic-bootp 10.254.239.40 10.254.239.60;
#option broadcast-address 10.254.239.31;
#option routers rtr-239-32-1.example.org;
#}
#A slightly different configuration for an internal subnet.
#subnet 10.5.5.0 netmask 255.255.255.224 {
#range 10.5.5.26 10.5.5.30;
#option domain-name-servers ns1.internal.example.org;
#option domain-name "internal.example.org";
#option routers 10.5.5.1;
#option broadcast-address 10.5.5.31;
#default-lease-time 600;
#max-lease-time 7200;
#}
#Hosts which require special configuration options can be listed in
#host statements. If no address is specified, the address will be
#allocated dynamically (if possible), but the host-specific information
#will still come from the host declaration.
#host passacaglia {
#hardware ethernet 0:0:c0:5d:bd:95;
#filename "vmunix.passacaglia";
#server-name "toccata.fugue.com";
#}
#Fixed IP addresses can also be specified for hosts. These addresses
#should not also be listed as being available for dynamic assignment.
#Hosts for which fixed IP addresses have been specified can boot using
#BOOTP or DHCP. Hosts for which no fixed address is specified can only
#be booted with DHCP, unless there is an address range on the subnet
#to which a BOOTP client is connected which has the dynamic-bootp flag
#set.
#hostfantasia {
#hardware ethernet 08:00:07:26:c0:a5;
#fixed-address fantasia.fugue.com;
#}
#You can declare a class of clients and then do address allocation
#based on that. The example below shows a case where all clients
#in a certain class get addresses on the 10.17.224/24 subnet, and all
#other clients get addresses on the 10.0.29/24 subnet.
#class"foo" {
#match if substring (option vendor-class-identifier, 0, 4) = "SUNW";
#}
#shared-network 224-29 {
#subnet 10.17.224.0 netmask 255.255.255.0 {
#option routers rtr-224.example.org;
#}
#subnet 10.0.29.0 netmask 255.255.255.0 {
#option routers rtr-29.example.org;
#}
#pool {
#allow members of "foo";
#range 10.17.224.10 10.17.224.250;
#}
#pool {
#deny members of "foo";
#range 10.0.29.10 10.0.29.230;
#}
#}

From the above file you need to configure bold options and change domain name where it says yourdomainname.com

Finally you have to restart the dhcp service by using the following command

sudo service isc-dhcp-server restart

DHCP server testing

You can check if your dhcp server is working properly bt running the following command

sudo netstat -uap


Can't get grub2 to install and be able to dual boot windows and ubuntu from same SSD

Install Ubuntu in UEFI mode to be Compatible with Windows
You can only boot both Windows and Ubuntu from the same disk if they are installed in the same BIOS/UEFI mode.
It sounds like your Windows is installed in UEFI mode, so you must install Ubuntu in UEFI mode also.
Rufus has a GPT "Partition scheme". If you use that when making the boot disk Ubuntu Live will only boot in UEFI mode, which will ensure that Ubuntu is installed in UEFI mode and will be compatible with your Windows.

After install run sudo update-grub to put Windows on the Ubuntu grub menu.


Multiple kernels choices realtime or no realtime

The easiest way would be using a lowlatency kernel, which you could do by installing the appropriate meta package linux-image-lowlatency, respectively linux-image-lowlatency-pae for 32 bit systems.

With different kernels installed, grub will allow you to choose between the available kernels when booting. So you could use the lowlatency kernel for music sessions and a 'normal' one for power savings.

I recommend using the lowlatency kernel instead of a realtime kernel because there currently are no official packages for the latter – as per this question here on AskUbuntu – and thus even the Ubuntu Studio guys recommend trying the lowlatency kernel first.


Is it possible to customize/configure Ubuntu to have Vim-like features?

You just opened a nice can of worms there. The question is, how far down the hole do you want to go?

So first you have your desktop yourself. By default, you have gnome, and that's
great and all. If you're looking to go more keyboard friendly though, check out
alternative window managers. I'm a big fan of tiling window managers like
AwesomeWM and Xmonad. These allow you to move, resize, and jump around much
more keyboard friendly.

Next up, you have your terminal you use. Bash is the default there, and you can
set it to enable vim movements/commands while you're working in the terminal. I
find ZSH (alternative to bash) has much better Vim mode support, so I use it on
a daily basis.

Next up you get to other tools. As Jorge mentions, there are plugins for
Firefox and Chrome that will enable some keyboard friendly, vim-like
functionality.

We also have other programs that are more vim-like. For instance, mutt is a
command line email program that has vim-like commands. You use j/k to move
through messages, can set vim as your email composition tool, and get to tweak
the setup.

Finally, you can look to do more things in vim itself. Rather than use gwibber,
you can install the twitvim plugin and use that for doing your social media
stuff.

I don't go into too many details because you just ask if it's possible. The
answer is, definitely! It's not just a flip of the switch though, and it can
take quite some time to learn and get used to all of the tools out there that
help with the keyboard-friendly OS mission.


How do I get a larger screen resolution in VirtualBox on Mac OS X?

I fixed the problem by doing:

Turn off 3D Acceleration in the VB settings -- that's why the Guest Additions were locking up after login.
Run this in the terminal of your ubuntu virtual machine, not the host OS:

apt-get update
apt-get upgrade
apt-get install dkms
apt-get install build-essential

Go to the Devices menu and tell it to install the Guest Additions. A new CDROM will appear on the desktop. Rightclick and choose the Autorun.
Restart the VM.
Now resize the VM window or choose Full Screen mode and it will resize the desktop screen resolution properly.


How to login to the GUI from commandline

you should be able to achieve this with startxfrom the TTY.

If this is not the case you should be able to set that up by creating or editing the .xinitrc in your home directory and using the startx command. I'm not sure if this is set up in Ubuntu by default or by some other means but there is some useful information On the Archwiki


dd: warning: partial read (2147479552 bytes); suggest iflag=fullblock

Try this:
Run in a terminal:
sudo apt update
sudo apt install --reinstall util-linux
sudo fallocate -l 4G /swapfile


Which version of Python is used on Quickly?

If you check here: Package: quickly on http://packages.ubuntu.com/

You will see that it depends on the package python.

Which on 12.04 is version 2.7.3
on 13.04 it's 2.7.4

For other releases of Ubuntu in a terminal enter

python --version

The number returned is the version of python its using.

If you want to use python3 instead take a look at this question


How do I check if I have the beta or stable version of Kubuntu?

After the release announcement is made, check that all your packages are up to date, e.g., sudo apt-get update && sudo apt-get upgrade should say

0 upgraded, 0 newly installed, 0 to remove and 0 not upgraded.

If it does, you are on "the final release" (i.e., you have the same set of packages as someone who downloaded the release ISO and installed from it).


In /usr/share/xsessions/ffKiosk.sh:

#!/bin/bash
gnome-settings-daemon &
while true ; do firefox -height 768 -width 1024 ; sleep 1s ; done


No desktop showing in Ubuntu 13.04 via VNC on a VPS

or simple solution use xfce4 instead of gnome

# apt-get install gnome-core xfce4 firefox nano -y --force-yes

and use this xstartup file

#!/bin/sh
unset SESSION_MANAGER
unset DBUS_SESSION_BUS_ADDRESS
startxfce4 &

[ -x /etc/vnc/xstartup ] && exec /etc/vnc/xstartup
[ -r $HOME/.Xresources ] && xrdb $HOME/.Xresources
xsetroot -solid grey
vncconfig -iconic &

xfce4 is way better and faster than gnome for vnc on ubuntu.


Dependency is not satisfiable: libdevmapper1.02.1(>=2:1.02.20)

You should double check the download from the Oracle site (http://www.oracle.com/technetwork/server-storage/virtualbox/downloads/index.html). I had the same issue, but realized I download the version for 15.10 instead of 15.04 (my current Ubuntu version). When I downloaded the correct version, it installed without any problems.


Cannot install xubuntu 11.04 because of "signal out of range"

I have found a solution based on GUTSY here: http://ubuntuforums.org/showpost.php?p=4380153&postcount=8  Yes, I know Gutsy is alot older so this might not even come close to 11.04's install but #10 will always work :-D

edit: #9 is certainly invalid for 11.04. #5 is the one that will tell you if this still works in 11.04. Please report back with the answer ;-)

From that post:

First, boot your system with the Ubuntu Live CD.
At the Ubuntu boot up screen, make sure that the first item (Start or Install Ubuntu) is active and press F6.
Replace the words "quite splash --" with "single" without the quotes and press Enter to continue.
Some text messages will flow. When the boot process is complete, you will find yourself logged as root in text mode.
When (or if) you reach the text prompt at the end of the boot up process, issue this command: dpkg-reconfigure -phigh xserver-xorg  Select "vesa" as the driver and "1024x768" and “800x600” as the resolutions.
Exit the root session either with "exit" or "Ctrl+D".
The system will automatically load to the graphical Live CD environment. If not, you can force it manually by entering "startx".
If this does not work, then repeat the same steps and select a different low resolution proportional to your screen size.
Normally, this step is not necessary, but just for your information; you can also write "nano -w /etc/X11/xorg.conf" or if you are familiar with Vi Editor, "vim /etc/X11/xorg.conf" to edit the resolutions manually in the "xorg.conf" file.
Otherwise, the only option you have is to download Ubuntu Alternate CD from:
http://www.ubuntu.com/getubuntu/download


Problem installing PyDev and SDK installation in Eclipse

Use the following setting and you will be all set.
Go to Window --> Preference --> General --> Network Connection --> select Direct from drop down!

here check for any wrong proxy entry- means you dont have any *local or  set to native provider in Proxy bypass also make sure not to have any other HTTP in proxy entries seted to native.

thats all.


What is the algorithm if it's not MD5?

Ubuntu by default uses sha512. See ....

cat /etc/login.defs

My password in /etc/shadow starts with $6$
I believe we started using sha512 instead of MD5 since Ubuntu 9.10.

  Anyway to change the length of the salt?

mkpasswd

lets you use variable salts.


Selecting home directory at installing Ubuntu on Win10

Assuming that you are referring to installing Ubuntu on Windows through WSL, you really don't need to set your C:\ root as the "home directory".  By default, WSL auto-mounts existing Windows drives, so you should find /mnt/c already exists in your WSL installation, and all the files/directories from that drive are available to you through Linux commands.
There's one huge caveat here, though.  If you are going to do this, I highly recommend using WSL version 1, not WSL2.  While WSL2 has its uses, working with the Windows/NTFS filesystem is not currently one of them.  WSL1 is much faster (see this) for accessing files on your Windows drive(s).
I actually keep both WSL1 and WSL2 instance around for this very reason.  If I plan on doing something with Windows files, I use the WSL1 installation.
Double-check which version you are using with wsl -l -v.  If it's WSL2, then you can do one of two things.
First option, just change the version using wsl --set-version <distro> 1.  Note that I would (personally) still recommend a backup first anyway (using wsl --export).
Second option, which is my preference, is to create a clone/copy of your existing instance, so that you have both WSL2 and WSL1 around.  While a bit "detailed", this is how I do it ...

Create a directory somewhere convenient where you want to work with your WSL images.  Of course, I name mine WSL.  I have mine under My Documents\WSL.

cd to that directory.

Create two subdirectories, images and instances.  Again, the names are really up to you.

wsl -l -v just to confirm your current distribution names.

Back up your existing 20.04 distro using something like wsl --export Ubuntu images\2021-02-05_Ubuntu20.04_snapshot.tgz (assuming your distribution is named "Ubuntu", of course).

Create a new instance using that snapshot using something like wsl --import Ubuntu20.04_WSL1 instances\Ubuntu20.04_clone images\2021-02-05_Ubuntu20.04_snapshot.tgz --version 1.

Launch that instance using wsl ~ -d Ubuntu20.04_WSL1.  Or restart Windows Terminal (assuming you are using it) and the new instance should be detected automatically.

The new instance will launch as root by default.  You will need to set your username by creating a /etc/wsl.conf with the following:
[user]
default = me

... of course, substituting your username.

Exit and restart that distribution, and confirm that your environment is operating as you'd expect.


how-to using ubuntu
Brasero (Included by default)

Brasero is a application to burn CD/DVD for the Gnome Desktop. It is designed to be as simple as possible and has some unique features to enable users to create their discs easily and quickly.

K3B (Available in the software center)

K3b (from KDE Burn Baby Burn) is a CD and DVD authoring application for the KDE desktop environment for Unix-like computer operating systems. It provides a graphical user interface to perform most CD/DVD burning tasks like creating an Audio CD from a set of audio files or copying a CD/DVD, as well as more advanced tasks such as burning eMoviX CD/DVDs. It can also perform direct disc-to-disc copies. The program has many default settings which can be customized by more experienced users. The actual disc recording in K3b is done by the command line utilities cdrecord or cdrkit, cdrdao, and growisofs. As of version 1.0, K3b features a built-in DVD ripper.

If you use GNOME see this to make it look native


Move Ubuntu server from 64gb SD to 16gb USB

Problem is sudo dd if=/dev/sda of=/dev/sdb copies whole device not caring what partitions and how many are there.
Solution is add count parameter

sudo dd if=/dev/sda of=/dev/sdb count=...

to find count number

fdisk -u -l /dev/sda

where sda is the disk you are copying from

as count use number in the End column of last partition you want to copy. And make sure you are copying from/to correct devices.

Other possibility should be (i am pretty sure this works would like some confirmation) copying the partition table first like its described here
https://unix.stackexchange.com/questions/19047/how-can-i-quickly-copy-a-gpt-partition-scheme-from-one-hard-drive-to-another/19051#19051

and then copy just the partition you want with

sudo dd if=/dev/sda1 of=/dev/sdb1

assuming you want to copy first partition


How can I add my weather indicator to Startup Applications?

How to find out

I installed my-weather-indicator from its ppa: ppa:atareao/atareaoto find out. Its .desktop file in /usr/share/applications includes the line:

Exec=/opt/extras.ubuntu.com/my-weather-indicator/bin/my-weather-indicator

which indicates the command you need to run is:

/opt/extras.ubuntu.com/my-weather-indicator/bin/my-weather-indicator

You can see the content of the file by running the command:

cat /usr/share/applications/extras-my-weather-indicator.desktop

or:

gedit /usr/share/applications/extras-my-weather-indicator.desktop

Sometimes launchers (.desktop files) have multiple lines, starting with

To add it to Startup Applications

Choose Dash > Startup Applications > Add, and add the command

/opt/extras.ubuntu.com/my-weather-indicator/bin/my-weather-indicator

More information

The command you tried does not include the path to the executable:

my-weather-indicator

This only works if the executable is in $PATH. The application however is installed in:

/opt/extras.ubuntu.com/my-weather-indicator/bin

You can find out which directories are in $PATH by the command:

echo $PATH


I suggest to use blender. Not because it is especially suiting for this case, but because it is open-source and versatile.

You can find it in your ubuntu software store.

What you need to know about blender: It has a very steep learning curve, but once you understand it, you can do pretty much anything with it. From image editing over creating games to making renderings undistinguishable from real life footage.

For "covering up": Use the sequence editor and combine your footage via Alpha filters and whatever you wanna cover it up with(3D-model or video snippet). You may wanna use Motion tracking, which is integrated. Can't get more specific than that without having more information...


Thumb drive: performance, web browsers, disk reads and writes

What you're experiencing is related to the NAND technology underlying your USB stick and is unrelated to the USB standard.
The short answer:
All USB sticks are created equal but some are more equal than others!  E.G. a USB 2 SLC stick is faster than a USB 3 QLC one.
The long answer:
The USB standard defines the connectors, cabling, power consumption and signalling and defines the maximum speed a device can work at.
The underlying NAND memory defines the minimum speed at which the USB stick works:

SLC: four times as reliable and four times as fast as QLC and four times as expansive to manufacture
MLC: half the speed and half the reliability of SLC but half the price
TLC: 1/3 the speed and 1/3 the reliability of SLC but 1/3 of the price
QLC: 1/4 the speed and 1/4 the reliability of SLC but 1/4 of the price

As you didn't mention any part numbers, I'm guessing that the SAN-Disk is using MLC and the PNY one is using QLC (SLC USB sticks are hard to come by nowadays and are not generally stocked and need to be ordered)


Can I make the launcher Icons smaller than 32 pixels?

12.04 and later
Am guessing that when you say "smallest setting" you mean the Unity plugin in the CCSM (CompizConfig System Manager). For the moment the 32 value in the Experimental Tab for the "Launcher Icon Size" is the smallest that is available. I also believe a smaller value should be available. 28, 24, 20, 18 to a minimum like 8x8 (For people like me with insect precise eyes).
There is an option with gconf-editor in the schemas/apps/compiz-1/plugins/unityshell/screen0/options/icon_size address. But the value is  and currently is not editable. It will soon be however.
UPDATE - Starting with 13.04, users will be able to resize the icons from 8 to 64 through the CCSM.
First install the CCSM (Compiz Config Settings Manager) if you have not yet done so:
sudo apt-get install compizconfig-settings-manager`

In Dash, type cc which should show the Compiz Config Settings Manager app. Open it and go to the Unity plugin:

Select the Launcher tab:

Change the value in the Launcher Icon Size option:

You can change it from 8 to 64. The only deal is, if you right click the Desktop and select Change Desktop Background, the value for the icons found there will be the one applied. Right now, both, the CCSM Icon size and the Desktop Icon size or not using the same variable for this.
As suggested by Ben Lutgens in the comments you can easily accomplish the same by typing the following in the termina:
dconf write /org/compiz/profiles/unity/plugins/unityshell/icon-size "24"

where the 24 will be the icon size. You can change this value from 8 to 64 depending on your TV, Monitor or Display. In my case 20 is perfect.


Is it possible to install ubuntu frontend on lubuntu?

You can install any additional desktop on an Ubuntu release. To install the regular desktop, issue the command
sudo apt install ubuntu-desktop

This will pull in all packages deemed essential for the default Ubuntu desktop.
Once installation is successful, you can switch to that new desktop environment on the log-in screen. Click the cog wheel and select the Ubuntu desktop session before entering your password.
The regular Ubuntu desktop is, of course, not as lightweight as the Lubuntu desktop, so take that into account.
If you wish to undo the change, then take your precautions when installing ubuntu-desktop. The command will list all packages that are going to be installed. Copy these into a file, in case you later want to remove the Ubuntu desktop again. It is not possible to automatically do so by removing the ubuntu-desktop metapackage, followed by an autoremove, because core packages installed with it are marked as "manually" installed, even if you pulled them in through this metapackage.


ro means 'mount the file system as read-only'.

the reason this is done is because fsck (the file system checker) should never be run on a read/write file system.

it's a default for a very good reason, and i would be very wary of changing it.


How do I show a list of applications in Unity?

When you open Dash->More Apps or the Application Lens, the applications are shown as icons with their name underneath. Both these options also allow filtering the results by a category.


Ubuntu flash disk not booting on Acer Aspire

If you have a windows machine available I just used the Rufus app to make a bootable image.

http://rufus.akeo.ie/

https://www.ubuntu.com/download/desktop/create-a-usb-stick-on-windows

Not avail in Linux though. Only Windows.

NOTE: Also Like someone above said, depending on your USB Flash drive brand, there is a possibility for it to brick after making it bootable. I bricked mine after successfully installing 16.04 LTS. Theres a particular way to reverse the process if you want a normal drive back, which I didn't pay heed to, I just formatted it as normal and it bricked. I can't recall the link or method, DISKPART in windows to restore the MBR is one way. Otherwise it's probably safer to keep the USB bootable image as is.

Sorry if this is a vague answer, it was a "quick and nasty" way for me to install Lubuntu and my USB flash drive was an old cheapo disposable one. May or may not be suitable for your requirements.

Also in my BIOS, I used Legacy HDD IDE mode (No AHCI), No Secure Boot and No UEFI for it to install successfully after a couple times trying with other settings.


How do I fix invisible tooltips in Skype?

Installing the following GTK2 rendering engines can help:

sudo apt install gtk2-engines-murrine:i386 gtk2-engines-pixbuf:i386


I my case solution was also change user record in my /etc/passwd from {user}:x:1001:1001::/home/{user} to {user}:x:1001:1001:{user},,,:/home/{user}:/bin/bash


How do I prevent my computer from going straight to Windows?

I have a really similar computer to yours (the v570). I made a post in the forum detailing a fairly straight forward way to get the boot loader to work and finish the installation. Let me know if you have any more questions. Here is the link:

http://ubuntuforums.org/showthread.php?t=1863125


After enabling hibernate grub menu appears on start-up with 30s timeout

I had a 30s Timeout after hibernating, the undocumented setting GRUB_RECORDFAIL_TIMEOUT worked for me:

GRUB_RECORDFAIL_TIMEOUT=$GRUB_TIMEOUT

See this Answer for more Details.


installed AMD catalyst driver and am stuck with 800 x 600 resolution and no unity sidebar

I had the same issue with every AMD driver BUT the stock one.
You can revert back to the stock drivers by opening the terminal and them settings.
Follow the instructions below:

Ctrl+Alt+T (all at the came time!)
Type in "gnome-control-center" missing " and hit Enter.
In System Settings go to:
Software Sources
Additional Drivers
Select Open Source Driver (should be top one, Open Source is recommended as Ubuntu devs can improve it and I've found AMD drivers to crash Unity & screen resolution) & Apply Changes!

Hope this helps!


How to change the SATA Mode from AHCI to IDE to install Windows XP for dual boot? (Ubuntu installed first)

If you tried out Ubuntu, and you found it's not your cup of tea, great. However, I would not recommend installing Windows XP, as it is no longer supported by Microsoft as of April 8. I would suggest either A) just go back to Windows 7 or B) try out another Linux distro, such as Xubuntu. There are plenty of options to choose from.

However, if you really want to install Windows XP, AFAIK there is no way in software to change the BIOS. Here are my suggestions:

Make sure you know what button to press when your computer starts up (some common ones are F12, F7, and Del)
Check your BIOS settings again. You may have missed something if you actually have looked in there.
Like I said before, just don't try installing XP. I honestly don't think it's worth it.

EDIT: I guess this is not what you wanted. I'm going to try again.

Here are my suggestions if your computer won't let you install Windows at all:

Burn a GParted CD on one of your computers--whichever one works at the moment.
Boot to the GParted CD and create a new partition table on your disk. You probably want to create a Master Boot Record partition table, seeing as you originally had Windows 7. If your computer actually has UEFI (which is a possibility), use a GUID partition table instead.
If installing Windows still doesn't work, try booting into GParted again and creating an NTFS partition on your hard drive.
If all else fails, bring this up on Super User. There should be people there who know more about your problem. This is clearly not an Ubuntu related issue, except for the fact that you want to switch back to Windows from Ubuntu. This is as far as I will help you here.


echo (unlock password) | sudo -S dislocker -r -V /dev/sdb1 -u -- /media/bitlocker
echo (root password) | sudo -S -i
cd /media/bitlocker/
mount -o loop dislocker-file /media/mount

Save this as script.sh in gedit. Use chmod +x script.sh in the directory you created the file. Run the script --> ./script.sh

Edit: added -S after sudo


HP DM4-3060EF Beats Edition - Will it be all ok with ubuntu?

I have the same laptop, been running 12.04 for 5 months or so, all running well, although it took a long time to get the broadcom drivers to work properly, and I think they still don't- connection to APs takes a long time.
 The fingerprint reader has no drivers, and the graphics card drivers need to be installed from the manufacturer, but there is a linux driver.
Switche-able graphics never worked right, but I dont care about that so much- usually plugged in.
Upgrading to 12.10 alpha today, same problems with broadcom, installing graphics now, everything else works(have given up on the fingerprint sensor)

Overall performance is good, smooth ride.

Paul

P.S- Since writing this things have come to light, wireless seems to work out the box, the ATI card has no support- so intel sandybidge is used- but the ATI card is still powered; causing the laptop to overheat and the fan to constantly run (reducing battery)- edit rc.local and add "echo OFF > /sys/kernel/debug/vgaswitcheroo/switch" to work arouond this.. it's been more than a year and no fix yet...

Also the subwoofer isn't activated because the hd sound model isn't supported- I initially used the model for the dm7 (in alsabase), but this doesnt seem to work in 13.10- if it works for you you need to swap the channels for the front speakers and the subwoofers afterwards...

Paul


Easy test: If you can change launcher position to bottom you are running 16.04

Also, don't trust wallpapers ;)


Cannot start hadoop "localhost: nice: cannot set niceness"

May be you can see this answer: https://github.com/Linuxbrew/brew/issues/695#issuecomment-386121530.
It says "You can safely ignore this warning. It's an upstream bug in Microsoft Windows."


Open the K Menu Editor from command line

From the command line just run kmenuedit to bring up the  K Menu Editor.
Hope this helps!


Disabled OpenGL and when i reenabled it, I couldn't reactivate features

Reset Compiz Configurations
Run this in Terminal:

rm -r ~/.config/compiz-1; rm -r ~/.gconf/compiz-1; rm -r ~/.gconf/compizconfig-1; rm -r ~/.compiz-1

Then reboot your computer.


Ubuntu 18-04 - no HDMI audio with AMD Radeon HD 7870

You may need to add kernel parameters to /etc/default/grub.

sudo nano /etc/default/grub

Look for GRUB_CMDLINE_LINUX_DEFAULT and add amdgpu.dc=1 (or, if it doesn't work, radeon.audio=1).  Then update grub and reboot:

sudo update-grub

Then look at the last tab in pavucontrol for a profile that includes HDMI output.


Gnome menu crashes or misbehaves while creating or opening folders in Ubuntu 20.04 LTS(fresh install)

This is a problem with the Ubuntu dock extension. Look at this:

https://askubuntu.com/a/1242658/1086027

https://bugs.launchpad.net/ubuntu/+source/gnome-shell-extension-ubuntu-dock/+bug/1872268


I had good experiences with "gthumb" in similar cases. Install it from the softwarecenter or typing "sudo ap-get install gthumb" in the terminal. Then right click on the image file, open with...


How can I change displayed name as sender?

Don't use mail, there are better command-line MUAs, such as mailx (package bsd-mailx) or mutt.

mailx will do what you want with the -r flag:

echo Test. | mailx -r "Joe Sender <sender@domain.com>" -s Test recipient@domain.com

You can likewise specify a display name for the recipient, by the way.

The nickname shown in for instance gmail.com comes from the part of the From field that is outside <sender@domain.com>, so in this example it would be Joe Sender.


Here is how I got it installed.  I downloaded it from here.  Once downloaded I used Gdebi to install it.  If you don't have Gdebi installed, just press Ctrl+Alt+T on your keyboard to open Terminal. When it opens, run the command(s) below:

sudo apt-get install gdebi

Once installed, just open the file with it, and click install.  See images below.


BQ Aquaris Ubuntu ed SIM cards not recognized anymore

I have solved it yesterday by reinitalizing the phone to factory settings (System settings → Reinitalize or something like this...)
Now my SIM cards are both recognized and my carrier providers are happy because I paid a lot for SIM cards which I didn't need :|


It is not a language. It is simply the certificate, and the BEGIN/END are simply markers to state the content in between is the certificate data.


What this script does:

In /etc/default/grub

replace

GRUB_CMDLINE_LINUX_DEFAULT="quiet splash"

with

GRUB_CMDLINE_LINUX_DEFAULT="quiet splash nomodeset video=uvesafb:mode_option='$resolution',mtrr=3,scroll=ywrap"
set GRUB_GFXMODE=$resolution

In /etc/initramfs-tools/modules

add uvesafb mode_option=$resolution mtrr=3 scroll=ywrap

In /etc/initramfs-tools/conf.d/splash

add FRAMEBUFFER=y

Reverse whatever it actually did do, and do this:

 sudo update-grub2
 sudo update-initramfs -u


Add ifort as a symbolic link in the /usr/bin folder. That solves the whole problem.

sudo ln -s /opt/intel/composer_xe_2013.1.117/bin/intel64/ifort /usr/bin/ifort

Replace the path with whatever version of Intel Composer you are using.


I have solved the problem. I changed "Color Mode" from "Color" to "Grayscale" and now everything prints (in black and white) as it should.


Ubuntu Mate 20.10 on Rasberry pi 4 does not recognize 2nd monitor

This is likely related to the FKMS overlay loaded. Fortunately it’s not too difficult to resolve.

Open the /boot/firmware/syscfg.txt For editing:

sudo vi /boot/firmware/syscfg.txt

Add the following line at the bottom of the file:

dtoverlay=vc4-fkms-v3d

Reboot

Now you should see both monitors available in Ubuntu.
Note:
Sometimes there may be a frame buffer issue that needs to be resolved as well. This can be done by opening the same file as before and adding this:
disable_overscan=1

Hope this helps.


Replace strings in a file with another matching string from another file

First of all your file1 does not have any specific delimiter, second you have same keys with different values like "Rv0002 S" and "Rv0002 L".

As your desired  output shows, I consider all lines are sorted and you just want to join these two file together.

Here is what I would do:

sed -r "s/(^Rv[0-9]+\s).*(\s+[A-Z]\s+).*/\1\2/" file1 > list1

It will create a list of keys for me like:

$ cat list1
Rv0001  T
Rv0002  S
Rv0002  L

After all I'll join them and cut my desired fields:

$ join list1 file2 | cut -f2- -d' '
T  -0.581372258 -0.147459774 0.548735372 1.001137114
S  -1.555384307 0.386044242 0.046125098 -0.06681665
L  -1.555384307 0.386044242 0.046125098 -0.06681665


I use Skype and have downloaded and installed it successfully. It's downloadable at this site,  just choose the correct version of ubuntu. http://www.skype.com/de/download-skype/skype-for-computer/ enjoy !!! ;-)
Problem Solved !!! By the way,  I use Skype 4.3 for linux,  successfully in Ubuntu 14.04.1


sudo will not run. Can I upgrade from 18.04 to 20.04?

I'd strongly suggest trying to fix your system first before trying to upgrade. Boot from the LiveCD and mount your partitions below, say, /mnt/ubuntu1804. chown -R o-rwx /mnt/ubuntu1804/etc/sudoers* should stop sudo from complaining, but of course, you need to fix a lot of additional files.
In a first step, make a new backup now (as already suggested in the comments). Afterwards,
find /mnt/ubuntu1804 -mtime 1 -ls >/mnt/ubuntu1804/old_access_rights.lst
find / -mount -exec chmod --reference={} /mnt/ubuntu1804/{} \;
find /mnt/ubuntu1804 -mtime 1 -ls >/mnt/ubuntu1804/new_access_rights.lst

should touch a small subset of files also found on the LiveCD ad give you an idea what to change accordingly (by comparing the .lst files). You should be able to use chroot /mnt/ubuntu1804 for simple tests (see "Rescuing using a Live CD"). If you're lucky, you're able to boot your old system again afterwards. Then, reinstalling all installed packages should also fix access rights (see "Reinstalling all […] packages").
That having said, the result--even if it works for you--should always be treated as a makeshift solution. An upgrade might work (as well) afterwards, but there's no guarantee that everything is fixed. Instead of investing (way) too much time to repair everything, better install Ubuntu 20.04 from scratch.


yes it is. Chrome actually open network-proxy (which is default install in ubuntu).


A terminal emulator for ex-Windows users

The second task can be done running following commands in terminal:

gconftool-2 -t str -s /apps/gnome-terminal/keybindings/copy "<Control>c"
gconftool-2 -t str -s /apps/gnome-terminal/keybindings/paste "<Control>v"


How to use the find command to list the path names of files including spaces?

Try this one:

$ find Downloads/ -iname "* *" -print0 | xargs -0 ls
'Downloads/Cloud/Multi-Runtime Microservices Architecture.pdf'

$ cp 'Downloads/Cloud/Multi-Runtime Microservices Architecture.pdf' .

More ways to do it.


TCP IP Socket Client - Available Options?

nc <server> <port>

After that, everything that is typed in is sent. Data from server is printed.

To get more flexibility, make a fifo mkfifo myfifo and read from it:

tail -f myfifo | nc <server> <port>

Then from other terminal window the files can be sent:

cat myfile > myfifo


Killer Wireless 1650 on Ubuntu 18.04 doesn't work

I finally suceedeed, so I summarize the detailed instructions, hoping it can help some people.

Apparently it's important to turn off your secure boot before the following actions.
To fix the No Wifi Adapter found, you need a Internet connection. If you have an Ethernet port on your laptop it's good, else, you have to use an adapter. Personnaly I used a USB-C to LAN adapter and it works.
Once you have a connection, you can update and upgrade packages (Maybe not necessary, but always good) sudo apt update && sudo apt upgrade.
Execute all of the commands on this article:

sudo apt-get install git
sudo apt-get install build-essential

git clone https://git.kernel.org/pub/scm/linux/kernel/git/iwlwifi/backport-iwlwifi.git
cd backport-iwlwifi
make defconfig-iwlwifi-public
make -j4
sudo make install

sudo git clone git://git.kernel.org/pub/scm/linux/kernel/git/firmware/linux-firmware.git
cd linux-firmware
sudo cp iwlwifi-* /lib/firmware/

Before reboot, execute this command to update initramfs update-initramfs -u.
Now you can reboot.

You should be able to access wifi parameters now.
Thanks.


I always have to access Jupyter Notebook as a root user

Disclaimer: I have no experience with Jupyter.

It seems that your Jupyter data files are owned by root and therefore your user may not write to them. This is most probably the case because you ran Jupyter as root.

To rectify, you need to change the ownership of the files to your user.

Run sudo chown -R sura:sura /home/sura/.local/share/jupyter and test if it works now. If it still does not work, check the error message. After the term "permission denied" is a path. Check the permissions of that path (ls -l <path>) and if the file or directory belongs to root, change then owner (sudo chown -R sura:sura <path>).

Afterwards, never run Jupyter as root, always as your user.


How can I bring back indicator-messages?

Maybe something went wrong when you tried to test and tweak things in the Ubuntu Unity desktop environment - and I know that you are doing this extensively and very often - thus remove the indicator completely (including the configuration files) and reboot the system :

sudo apt purge indicator-messages| sudo reboot

Reinstall it (the reason for restart is, that indicator-messages is an "autostart service") :

sudo apt install indicator-messages | sudo reboot

Now everything should work as expected again (if nothing else is broken from "testings").

Also check whether gsettings get com.canonical.indicator.messages applications
returns correct application entries such as the default setting ['thunderbird.desktop'].


Why is there 4.86(maybe 15.1) GB of USED-space on a newly partitioned and formatted 298 GB drive (as ext4 by Gparted)

Gparted, that use mkfs.ext4 to create a ext4 filesystem, reserves 5% of the space for super-user, as explained in man page:

-m reserved-blocks-percentage
   Specify  the  percentage  of the filesystem blocks reserved for the super-user.  This
   avoids fragmentation, and allows root-owned daemons, such as syslogd(8), to continue to
   function correctly after non-privileged processes are prevented from writing to the
   filesystem.  The default percentage is 5%.

Now, 5% of about 300GB is just the 15GB you see already used.

More interesting, you can avoid this if you feel do not need it, simply creating the filesystem with, for example,

sudo mkfs.ext4 -m 0 /dev/sda1

where 0 means 0%.

I think Gparted see more space because is run by super-user, so part of that 15GB are free for him. Nautilus is run by the user, so the space is less.


How to run psmouse with "proto=imps" on startup?

sudo modprobe -r psmouse && sudo modprobe psmouse proto=imps

stops psmouse and starts it with proto=imps option.

Startup applications is a wrong way to set options for kernel modules.

The correct way to achieve the desired result is to use modprobe.d config files.

Run in a terminal

sudo tee /etc/modprobe.d/psmouse.conf <<< "options psmouse proto=imps"

and reboot.

That will create the psmouse.conf file and psmouse will start with the desired option.


apache2 fails to install due to "Hash Sum mismatch" and "Bad header line Bad header data [IP: 192.168.1.151 808]" (Ubuntu 18.04)

Using sudo apt-get install software instead of sudo apt install software fixes the problem.


vim can not interact with system clipboards / Ubuntu

Problem Description: I downloaded Ubuntu in the Win 10 App Store, installed vim, vim-gnome, opened the + clipboard and + xterm_clipboard while browsing vim

But I vim: reg when there is no + clipboard or * clipboard, it can not be copied to the system clipboard

The cause of the problem: Ubuntu downloaded from the Win 10 App Store is without a GUI and needs to be installed with VcXarv

Solution: For those who want to go the X server route, let me leave my notes here.

Install VcXsrv (I found that Xing is outdated on sourceforge and
the new version is donationware)
If it starts after installing, stop it
Start it using XLaunch (search in the start menu), go with all the
defaults (ensure the clipboard options are checked)
At the end, save the configuration to a file (use that to start it
from now on) Put export DISPLAY = localhost: 0.0 in your .bashrc in
bash for Windows (and run the command in any open bash windows). The
reason I said say localhost is that this makes SSH X forwarding
work, see below.
Ensure vim is installed using clipboard support. Vim --version |
grep clipboard should say + clipboard, not -clipboard. Also if you
run the ex command: echo has ('clipboard') in vim and it says 0 it
does not have clipboard support compiled in. If you do not have
clipboard support, install the vim-gtk package (apt-get install
vim-gtk).
It should now work
As a bonus you should now be able to copy from and to your Windows
clipboard from a remote machine by using SSH X forwarding (ssh -X
...). You can use xclip on the remote machine or if you use vim
there you will again need to make sure the clipboard option is
compiled into vim (eg install vim-gtk). You can probably also
configure PuTTY to use your local X server in case you prefer using
that for remote connections.

(The solution comes from robbiev's comment, this is the link: https://github.com/Microsoft/WSL/issues/892)


Ubuntu 14.10 won't connect to a captive portal but will in a vmware client on same machine

sorry I haven't got enough reputation to comment but by using solsTice advice I managed to get a similar problem working on Ubuntu Gnome 15.04, so thanks, here is what I did:

Access the config setting via firefox : type about:config in the address bar, some window will come up about security hit ok I understand.

-Next you need to search for general.useragent.override if it doesn't exist left click screen go to new then string and call it general.useragent.override

-set the string value to : Mozilla/5.0 (compatible, MSIE 11, Windows NT 6.3; Trident/7.0;  rv:11.0) like Gecko, effectively setting you up as IE 11

-At this point still nothing happened for me so I hit in an address without the http:// to call a page and bingo I got mozilla trying to redirect me simple click allow and away you go hopefully.

Hope this helped


generally updates are resumable (not all but most of)

the partial downloads will not be deleted until

1).if the update (partially download) becomes absolute.

2).or you run any of these from terminal can cause to lose of partial downloaded update.

sudo aptitude clean - Will erase downloaded packages from cache

sudo aptitude autoclean - Will erase old downloaded packages from cache

sudo apt-get clean - Will erase downloaded packages from cache

sudo apt-get autoclean - Will erase old downloaded packages from cache

3). or you shut down your computer meanwhile your computer is applying changes can some time cause redownload of some of the packages (but not all)


Black/White lines on screen when scrolling or watching video (browsing)

There is are lots of posts, including video describing your problem with skylake processors here. Some reasons are because kernel version are < 4.4.18. Others are because of Chrome smooth scrolling option. Others are because Xorg is using sna instead of uxa.
On my own system (Intel Core i7 3630QM w/HD3000 graphics + Nvidia GT650M) I had screen tearing in chrome that went away after updates and/or removing smooth scrolling option. However different processors (mine is third generation, yours is sixth generation) can use different machine code which can present different problems/features/benefits.
When you read the link above and wonder what kernel version you are using open the terminal and type:
uname -r

Changing Kernel versions is not like upgrading Ubuntu 14.04 to 16.04 where you can't quickly go back. You can have multiple kernel verions in your Grub boot screen (under advanced options submenu).
Please keep us updated in your progress because I'm sure others like me suffer similar, if not the same, problem.


These instructions assume you have inserted a CD and that has been mounted as:

/media/MATHWORKS_R2012A/

That's clearly not happening so there's something going on. More modern copies of Ubuntu will use /media/$USER/MATHWORKS_R2012A/ but instead of scatter-gunning this, just open up the file manager go to the CD/DVD drive and see where it's mounted.

Control+L will give you the path (repeat to hide it). Then just cd into that path in a terminal (remembering to quote or escape any spaces or weird characters) and then run:

./install -glnx86 -v

Obviously if you aren't using a CD (network mount or whatever) the same approach applies. Find out where the files are, go to that location and call the binary.


NetworkManager broken after upgrade to Kubuntu Saucy

After seeing your other problems, I'm pretty sure the problem is with policykit or consolekit.

make sure you have policykit-1, policykit-desktop-privileges, polkit-kde-1 and consolekit installed.

if they are installed try reconfiguring them (sudo dpkg-reconfigure policykit-1 policykit-desktop-privileges consolekit polkit-kde-1).


You're suffering from the xorg bug 1405696 of the NVIDIA driver version 346. You can watch the status of the bug until it changes to Fix committed to use 346. Meanwhile you should stick with 340 by running sudo apt-get update && sudo apt-get install nvidia-340. In your case you might be obliged to type it blindly to try to install the driver in a chroot. The PPA versions are experimental and it might happen that such dramatic issues occur.


How do I tell the installer what my home directory is?

You can download the bsnes .deb package here: http://www.playdeb.net/software/bsnes
It contains the latest version for Ubuntu 10.10, 11.04. 11.10 and 12.04. Install the right one for your system.


Although you have a working solution, I'd like to give you some recommendations:

First of all, take a snapshot of your VMs.

When it's done, you should have used:

apt-get purge

instead of:

apt-get remove

You should probably have some misconfiguration or wrong config parameter/s, and that will clean it.

After that, install Virtual Box as usual, and import your snapshot.


Why is chkconfig no longer available in Ubuntu?

sysv-rc-conf is an alternate option for Ubuntu.

The usage is almost the same.

To install:

sudo apt-get install sysv-rc-conf

To configure apache2 to start on boot

sysv-rc-conf apache2 on

equivalent chkconfig command

chkconfig apache2 enable

To check runlevels apache2 is configured to start on

sysv-rc-conf --list apache2

equivalent chkconfig command

chkconfig --list apache2


No notifications for facebook or twitter in Gwibber

I would delete the /homedir/.config/gwibber directory and then setup the connections again to see if this solves your problem.


"You have launched an older version of thunderbird"

As noted in a comment by mook765, deleting the compatibility.ini file in your Thunderbird profile folder (~/.thunderbird/profiles/*/) might solve the issue for a single time, but the file gets recreated and updated with your version again.

Instead, Thunderbird can be launched with the --allow-downgrade option to ignore the last running version and launch the profile anyway, even if it was before updated to a higher version.

This might probably be dangerous if the last run migrated your profile data to a version that is not backwards-compatible, so it's always good to have regular backups anyway. Making sure you don't run wildly different versions but always keep all of them to at least the same major release should minimize the risk.

To always use --allow-downgrade, you might make a copy of your /usr/share/applications/thunderbird.desktop launcher file, place it in ~/.local/share/applications/ and edit all the lines starting with Exec=thunderbird to include that command-line option.


I had the same problem with my G580 i installed the win 7 and then tried to install the ubuntu. it used to swipe all the space and partition and then install itself.

now what i did was.

i installed ubuntu on the entire hd.
then using Gparted from live CD i created a ntfs patrition and installed windows on it.
now system will boot only in the windows because windows usually override master boot record.
now what you have to do is to repair the grub and add an entry for window 7 in it.

here this link will possibly help you.
http://www.faqforge.com/linux/restore-grub-bootloader-after-windows-installation-on-multi-boot-system/

now after going through above link you should be able to boot into  grub now all you need to do is to add an entry for windows in grub which can be easily done by booting into the linux and doing a few simple tasks.
for that do some googling yourself.

and let me warn you my friend  that while on lenovo g580 you wont be able to switch your wireless and bluetooth on/off using Fn+F5 there is some trouble in it. you'll have to boot into windows turn on the wireless and bluetooth and then boot back into linux to use is in it.

well!
i think you'll find it helpful.


I cannot run apt update properly - apt update hangs

I just encountered the same issue. The solution is to delete away the lock files in the xapian/default folder:

sudo rm /var/cache/app-info/xapian/default/flintlock /var/lib/dpkg/lock


No, it's unlikely to be backported for Lucid. Lucid is reaching the end of it's life next month, I highly encourage you to update at least to precise 12.04, which is quite nice.


How do I disable the discrete graphics and force the use of my integrated Intel HD graphics on an HP Envy 15t-3200?

vgaswitcheroo applies if there is a free driver from linux kernel and kernel modesetting is activated. So it should work if there is no fgrlx installed. I made my Sony VPCSA with similar setup (Intel 4000, Radeon 6600M) working.

I replaced a line in /etc/defalut/grub (1):

GRUB_CMDLINE_LINUX="video.allow_duplicates=1 radeon.modeset=1"

It fixed the problem for Ubuntu 12.10. However, that's not enough for Debian/unstable.
In addition, I had to add a line to /etc/modprobe.d/blacklist.conf (2):

blacklist radeon

And to /etc/rc.local BEFORE exit 0; (3):

modprobe radeon modeset=1
mount -t debugfs none /sys/kernel/debug/
echo OFF > /sys/kernel/debug/vgaswitcheroo/switch

If you have issues, start with (2). It has reliably resulted in a bootable system, than proceed with (3).


Cannot start Qt Creator after updating to 15.04

The actual problem was that suspending my PC had disabled 3D acceleration and Qt Creator didn't start...great.

As for the Pipelight stuff, I have no idea.


It seems from your photo that all partitions are mounted. (the key icon)
sda5 placed within the extended partition sda2.
You must resize sda2 first.


Click on Gear icon (Session Indicator) in Unity panel and open system settings and select "Keyboard Layout".

Click on little plus button to add a new layout, Search for Persian and add it.

Now you will see a keyboard icon in your Unity panel, Just click on it to switch between layouts.


netplan apply does not change the IP address

Netplan is fussy about how .yaml files are formatted. Don't try to "pretty-fy" them.

Is 50-cloud-init.yaml the only .yaml file in /etc/netplan?

So edit your .yaml file to look like this...

network:
  version: 2
  renderer: networkd                   # note the correct spelling
  ethernets:
    enp0s3:                            # identify the proper interface
      addresses: [10.0.2.100/24]
      gateway4: 10.0.2.1
      nameservers:
        addresses: [10.0.2.100]        # this is probably the wrong address
        addresses: [8.8.8.8, 8.8.4.4]  # use something like this instead

then do:

sudo netplan --debug generate  # generate the config files
sudo netplan apply             # apply the new configuration
reboot                         # reboot the computer

and recheck your ifconfig output.

Note: if it was me, I'd let NetworkManager manage this interface, and set the static address information into the "Wired Connection" profile.

network:
  version: 2
  renderer: NetworkManager

then do:

sudo netplan --debug generate  # generate the config files
sudo netplan apply             # apply the new configuration
reboot                         # reboot the computer


the screen rendering of 17.10 with intel i5-8400 is really slow

Ubuntu 17.10 is currently shipping kernel version 4.13. But the graphics driver for 8th generation coffee lake processors are merged in kernel mainline for version 4.15. (source)

Currently you can install 4.15 kernel Ubuntu builds to fix the graphics issue.

Download these debian packages

mkdir -p ~/linux_4.15 && cd ~/linux_4.15

wget http://kernel.ubuntu.com/~kernel-ppa/mainline/daily/2018-01-01/linux-headers-4.15.0-999-generic_4.15.0-999.201801010200_amd64.deb

wget http://kernel.ubuntu.com/~kernel-ppa/mainline/daily/2018-01-01/linux-headers-4.15.0-999_4.15.0-999.201801010200_all.deb

wget http://kernel.ubuntu.com/~kernel-ppa/mainline/daily/2018-01-01/linux-image-4.15.0-999-generic_4.15.0-999.201801010200_amd64.deb

dpkg -i *.deb

sudo update-grub

sudo reboot

Ubuntu should boot with the latest kernel image now. Your graphics rendering should be smooth.


How to customize Lock Screen theme in Ubuntu 20.04

In a fresh install of Ubuntu 20.04,
the default shell theme.. and lock screen both are configured to use the css file

Yaru/gnome-shell.css which is inside the /usr/share/gnome-shell/theme/Yaru/gnome-shell-theme.gresource

this is configured in the file /usr/share/gnome-shell/modes/ubuntu.json

{
    "parentMode": "user",
    "stylesheetName": "Yaru/gnome-shell.css",
    "themeResourceName": "theme/Yaru/gnome-shell-theme.gresource",
    "debugFlags": ["backtrace-crashes-all"],
    "enabledExtensions": ["ubuntu-dock@ubuntu.com", "ubuntu-appindicators@ubuntu.com", "desktop-icons@csoriano"]
}

So, you can pointout what ever .gresource file you want to use and the corresponding gnome-shell.css

for example, If I want Yaru-dark theme, I can simply point out like this by editing the file /usr/share/gnome-shell/modes/ubuntu.json

Take Backup of the file /usr/share/gnome-shell/modes/ubuntu.json before editing

{
    "parentMode": "user",
    "stylesheetName": "Yaru-dark/gnome-shell.css",
    "themeResourceName": "theme/Yaru/gnome-shell-theme.gresource",
    "debugFlags": ["backtrace-crashes-all"],
    "enabledExtensions": ["ubuntu-dock@ubuntu.com", "ubuntu-appindicators@ubuntu.com", "desktop-icons@csoriano"]
}

Please note that Default shell theme and lock screen uses same file.. so If you want Yaru shell theme for the desktop session.. you need to install it as a local theme which is another topic.

I have not tried with full path of the .gresource file.. in the line

"themeResourceName": "theme/Yaru/gnome-shell-theme.gresource",

this means.. theme/Yaru/gnome-shell-theme.gresource is a relative path of the base /usr/share/gnome-shell


You can have it done by editing your fstab file

sudo nano /etc/fstab

and adding in the related information about your partition (you can always visit the fstab man page)

#example entry for a ntfs-3g partition
UUID=BA2CB4532CB40C7F   /media/mount ntfs-3g defaults,noatime,users 0 0

you can get the UUID for your partition using fdisk -l to list all the partitions and blkid /dev/sda* (replace sda* with the actual name of the partition) to get the UUID

Sorry my answer is not extremely complete, but I'm quite in a hurry. Please feel free to edit it later and add some more details


Adding IPv6 address results in deactivated WIFI

The only way which worked for me: I added 2 files

for if-up: /etc/network/if-up.d/add-ipv6.sh content:

ip -6 addr add ipv6-address/64 dev wls3

and  /etc/network/if-down.d/add-ipv6.sh content:

ip -6 addr del ipv6-address/64 dev wls3


If you also have unwanted backup files in subfolders, it gets a bit more difficult:

find . -type f -name '*~' -delete


Installation problem after broken installation of zoom

Give a try to

sudo dpkg --remove --force-all zoom

This will uninstall zoom ; then you'll have to install zoom.

Replace amd64 by i386 for 32bit arch

wget https://zoom.us/client/latest/zoom_amd64.deb
sudo apt install ./zoom_amd64.deb

Zoom Guide


Ubuntu 14.04 won't boot after installation

After you boot with USB, you need to mount the / partion (the easiest way is using nautilus) and use chroot

sudo chroot /media/ubuntu/drivename

Then you can issue the grub update

 sudo grub-install /dev/sda4
 sudo update-grub


Permission denied(public key) in ssh while installing iotivity

When generating the keys use a name id_rsa without any extension. And use the following content in the config file:

Host iotivity gerrit.iotivity.org
Hostname gerrit.iotivity.org
IdentityFile ~/.ssh/id_rsa
User Teju
Port 29418


type 127.0.0.1 in your browser. it opens scanner page for nessus.


If you install the drivers from the Ubuntu repositories through the dedicated interface, PRIME should be installed automatically, and you will find the relative option in the Nvidia Settings interface:


Cat command with variable in file name not working

Variable assignation from cat:

content=$(cat /tmp/cygwin/cygwin/home/67642360/1.0.94/db/src/sql/oracle/updates/${line})
# Or
content=`cat /tmp/cygwin/cygwin/home/67642360/1.0.94/db/src/sql/oracle/updates/${line}`

cat a file from variable:

cat /tmp/cygwin/cygwin/home/67642360/1.0.94/db/src/sql/oracle/updates/${line}
# OR
cat "/tmp/cygwin/cygwin/home/67642360/1.0.94/db/src/sql/oracle/updates/${line}"


Try removing some unused dependencies and orphan packages. This will help.
It worked in my case. Run:

sudo apt autoremove && sudo apt autoclean

Also, you can install Gtkorphan (sudo apt-get install gtkorphan) to remove all orphaned packages and dependencies left behind by other apps.


My computer is unable to boot windows 7 after installing ubuntu 18.04, but windows is seen in GRUB menu. what should I do?

I'm not sure how many Windows partitions grub discovered on your system, but on my Dell laptop, it discovers two: a small "rescue" partition and a large "system" partition.

In order to boot into Windows 7, I find I must choose the small "rescue" partition from the Grub menu. It's counter-intuitive, but selecting the "system" partition does not work.


sudo apt-get autoremove

To remove old kernels; if that doesn't work I'm afraid you may need to expand the boot partition, which is much more involved.


How can I show notify-send messages triggered by crontab?

To execute any GUI related app from Cron you should export few desktop environment variables. The below solution is based on this answer where are provided more details.
How to launch any GUI related application from crontab in Ubuntu 16.04, 17.10, 18.04 and other Ubuntu distributions with Gnome
Create a startup script that will export the desktop environment variables and will launch your application. Let's call it gui-launcher. Its content should be (referencs: [1], [2] and [3]):
#!/bin/bash -e

# NAME: gui-launcher

# Check whether the user is logged-in
while [ -z "$(pgrep gnome-session -n -U $UID)" ]; do sleep 3; done

# Export the current desktop session environment variables
export $(xargs -0 -a "/proc/$(pgrep gnome-session -n -U $UID)/environ")

# Execute the input command
nohup "$@" >/dev/null 2>&1 &

exit 0

For other Desktop Environments change gnome-session in this part $(pgrep gnome-session -n -U $UID) with the name of the process of the DE in use, for example mate-session. A list of the most Ubuntu DE is presented here. Lubuntu implementation of the same script - here. The script could be used to launch GUI app from TTY or SSH session in the current user's Desktop session.
Make the file executable: chmod +x gui-launcher.
The script will work until the user is logged-in, including a locked screen.
Please don't modify and run the script as root. It could be harmful for the system!

Then use it within crontab in this way:
*/1 * * * * /full/path/to/gui-launcher "/full/path/to/the-targer-application"

Here is how it works on Ubuntu 17.10 on Wayland:

Here is presented an implementation of the same script over SSH: How to run script (.sh) files in a new terminal after connecting to Ubuntu 16.04 server via ssh?

Here are presented more explanations: Cron job to run python script at reboot does not work.

And one more example: Adjust brightness with xrandr and cron job


Configure virtual directory in sftp server

Since no one else answered, and I managed to solve it, I'm posting the answer myself.
Well, it was pretty straightforward. Instead of configuring it inside an sftp server, I did it the general way. I created a new directory under /var/www (or anywhere else). Then, I used the bind command to mount the desired directories there.

#As an example
sudo mount --bind /some/where /else/where
 #mounts /some/where under /else/where

Then, I just selected that directory as the home of the user. Done.


Virtualbox 6.1.10 not recognizing USB connections

You need to add your user to vboxusers group. With some VB versions it isn't done automatically for some reason.
Run:
sudo usermod -aG vboxusers $USER

then log off and on.


How to prevent the recovery mode menu to come up!

Recovery Mode in Ubuntu allows you to restore your system, change user passwords and gain root access to your Ubuntu machine in case of an emergency.

Open :

gksu gedit /etc/default/grub

To disable it :

Uncomment :

#GRUB_DISABLE_RECOVERY="true"

Save .

Update :

sudo update-grub


Format Filesystem to work with separate boot and data drives

Just start the Ubuntu installation, and in the partition menu, choose "Other" and do exactly what you said :

Create an EXT4 partition on the SSD, with a / mountpoint.
Create an EXT4 partition on the DATA drive, with a /home mountpoint.
You can also use a NTFS/FAT partition if you want, and link this disk to your '/home', with a shortcut directly.

PS : / and /home cannot be NTFS because of the permission used by NTFS being incompatible with the way Linux works. NTFS is indeed a Windows-related format.