Your laptop has the Intel i7-6700HQ 6th generation CPU known as "Skylake". It also has a NVidia Geforce GTX 970M GPU. To eliminate the dedicated Nvidia GPU from the equation you can temporarily work with only the integrated Intel GPU in the short term.

When using Skylake you made need updates:

Ubuntu 15.10: Various "types" of freezes and now unexpected shutdown
"W: Possible missing firmware for module i915_bpo" when updating initramfs
Ubuntu doesn't reboot

These are some of the answers I've written but there are many great answers others have written:

No version of Ubuntu can be installed with any Skylake 6th generation Intel processor
16.04: How to get the recommended intel-microcode package to fix hyper-threading issue?
Ubuntu 16.04 Skylake 6th Generation Screen Flickering
Ubuntu 16.04 Skylake overheating

Unfortunately not enough is known about your specific problems to point your question as a duplicate of an existing one.

One last thing to change is the Intel c-state max idle:

How to set intel_idle.max_cstate=1
System freezes completely with Intel Bay Trail

Although targeted at Intel BayTrail users it seems to have improved things for other Intel CPU users as well. If these fixes work I regard them as a work-around to make life better in the short term until a real solution is found.


Problem with Java and Ameritrade "thinkorswim"

I experienced the same issue.

Ubuntu 14.0.4 LTS

java version "1.7.0_65"
OpenJDK Runtime Environment (IcedTea 2.5.2) (7u65-2.5.2-3~14.04)
OpenJDK 64-Bit Server VM (build 24.65-b04, mixed mode)

The problem as captured in the screenshot is pointing to missing java class. This is because thinkorswim client is expecting a SUN Java JRE rather than Open JDK.

Install Sun Java JRE should solve this.


It turns out something broke in my openvpn setup with the update, and at the same time the openvpn configuration was reset to start the service upon login, without my being aware of it. I turned of the dysfunctional openvpn process and disabled the service in /etc/default/openvpn, (Autostart="none") and the internet worked again; Hallelujah.


Why do some icon themes have so many different sizes?

Software often makes use of different icons thus it needs icons to be in different sizes. The difference in sizes can be attributed to the context within the software they're used, for example: Icons for the toolbars don't need to be at 512x512  whereas icons in a dock or menu need to be at a higher size.

Also, icons need to be scaled properly so they don't lose their meaning.

So artists make use of the different sizes for this. An icon created in 512x512 will look good at 100% scaling and probably at 50% but at 12.5% (64x64) the same icon will look bad, details will be lost, it may look like something completely different, etc; so another icon specifically made for that size needs to be created.

Looking around I found that Gnome has a specification for the sizes:

I'd add to this that this is specifically for Gnome icons (mostly in SVG) and maybe the Tango and Tango-based icons though the table looks quite dated as Gnome includes icons larger than that nowadays and doesn't mention symbolic icons.

So depending on the artist these may be very well vary.

I generally group icons in the following sizes (size of the canvas) according to the context in which they will be used:

Contextual Menus, Toolbars, Mimetypes (very small), Mounted Devices (Nautilus sidebar).

16x16
22x22
24x24

Mimetypes (small-medium), Docks, Categorized Menus (Unity's Dash, Gnome Shell's application overview, System preferences), Desktop.

32x32
48x48
64x64
96x96

Mimetypes (large), Docks, Categorized Menus (Unity's Dash, Gnome Shell's application overview)

128x128
256x256
512x512


How can I trace the files and functions a particular terminal uses?

STRACE

  strace - trace system calls and signals

  In the simplest case strace runs the specified  command  until  it
  exits.   It  intercepts  and records  the  system calls which are
  called by a process and the signals which are received by a process.
  The name of each system call, its arguments and its return value are
  printed on  standard error or to the file specified with the -o
  option.

strace <command>

You can filter what you would like to trace using the -e trace= option. For example, strace -e trace=file <command> "trace all system calls which take a file name as an argument". Read the man page for more options.


Why is mysqld always running in the background?

It sounds like you have a docker container running that has mysqld in it.


"Error detecting shell" when launching Gnome Tweak Tool

I had a similar problem here, with a slightly different error:

Traceback (most recent call last):
File "/usr/bin/gnome-tweak-tool", line 76, in <module>
MainWindow()
File "/usr/lib/python2.7/dist-packages/gtweak/mainwindow.py", line 44, in __init__
model)
File "/usr/lib/python2.7/dist-packages/gtweak/tweakview.py", line 40, in __init__
self._model.load_tweaks()
 File "/usr/lib/python2.7/dist-packages/gtweak/tweakmodel.py", line 135, in load_tweaks
mods = __import__("gtweak.tweaks", globals(), locals(), tweak_files, 0)
File "/usr/lib/python2.7/dist-packages/gtweak/tweaks/tweak_shell.py", line 236, in <module>
  GSettingsSwitchTweak("org.gnome.settings-daemon.plugins.power", "lid-close-suspend-with-external-monitor"),
File "/usr/lib/python2.7/dist-packages/gtweak/widgets.py", line 116, in __init__
_GSettingsTweak.__init__(self, schema_name, key_name, **options)
File "/usr/lib/python2.7/dist-packages/gtweak/widgets.py", line 105, in __init__
options.get("summary",self.settings.schema_get_summary(key_name)),
File "/usr/lib/python2.7/dist-packages/gtweak/gsettings.py", line 122, in schema_get_summary
return self._schema._schema[key]["summary"]
 KeyError: 'lid-close-suspend-with-external-monitor'

I fixed the problem by forcing installation of version. 3.3.4. You can use the Synaptic Package Manager to accomplish this:

Remove version 3.4.0.
Remove rocoz PPA.
Install version 3.3.4.


Check your default route with

ip route

It should say "default" followed by the gateway address of your wireless network.

If you have more than one network connection, for example a wired network and a wireless one, it is possible that you have to tell ubuntu which connection to use to get to the internet.


Compiling python3 code in terminal with interpreter

What you are looking for is the -i switch. According to the manpages:

-i    When  a  script  is passed as first argument or the -c option is
      used, enter interactive mode after executing the script  or  the
      command.  It does not read the $PYTHONSTARTUP file.  This can be
      useful to inspect global variables  or  a  stack  trace  when  a
      script raises an exception.

So if your script name is name.py what you need to do is run:

python3 -i name.py


What is the correct address for precise/12.04 restricted, multiverse and universe ppa?

The bare minimum in sources.list is:

deb http://us.archive.ubuntu.com/ubuntu/ precise main restricted universe multiverse
deb-src http://us.archive.ubuntu.com/ubuntu/ precise main restricted universe multiverse

Edit sources.list using:

sudo -H gedit /etc/apt/sources.list

Then run:

sudo apt-get update

You can find more alternative using Ubuntu Source List Generator here


Quickly produces an error when installing

self.root in your setup.py file is None Which throws the exception.

Example:

# This is to mimic line 120 in your setup.py file
# target_data = '/' + os.path.relpath(self.install_data, self.root) + '/'
>>> os.path.relpath("/spam/eggs", None)
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/usr/lib/python2.7/posixpath.py", line 422, in relpath
    start_list = [x for x in abspath(start).split(sep) if x]
  File "/usr/lib/python2.7/posixpath.py", line 352, in abspath
    if not isabs(path):
  File "/usr/lib/python2.7/posixpath.py", line 61, in isabs
    return s.startswith('/')
AttributeError: 'NoneType' object has no attribute 'startswith'

It's the same traceback. I'm not familiar with Quickly, but you'll have to figure out why self.root is set to None and then fix it.


The settings for the microphone can be accessed by clicking on the sound icon at the top right bar, which looks like a speaker with the sound waves coming out of it.

If you click on that then you can see the option to open your sound settings.  Do this and go to input, which is microphone.  You might have a couple options like front mic or rear mic, and you might need to try out those options.

A lot of this has to do with your sound card which is usually on board your motherboard.  Can you tell me what kind of motherboard you have?

Oh, and sometimes the problem lies within Skype, try to open the options in skype and see whether you have options for your mic.


That major version isn't specific enough, all of our updates are reflected in the suffix, if that fix is really installed it's 0.9.1-1ubuntu5. In any event, if you somehow found an escape for this fix, it's a bug, and doesn't belong here, it belongs in launchpad. Thanks.

https://launchpad.net/virt-manager

Thanks.


I have a weird boot problem and haven't found a way to fix it!

Try running these commands and see if it fixes it.

sudo grub-install /dev/sdb (replace /dev/sdb with your own drive)
sudo update-grub

Hope it helps.


uninstall it and re-install maya sp1 from known sh.files provided on the internet after finishing install download maya 2014 sp4 and extract it and convert rpm to deb after that by start clicking on Debian file it will open it software center and click on re-install button in Maya2014_64-2014.0-986.x86_64 the software center will show upgrade button  are   maya SP4 will be ready to work after activating


maas-pserv main process ended, respawning

For the maas-pserv problem i've maybe a solution. I had the issue today also on one of my MAAS controllers and i found out that twistd has a cache file that contains all plugin information.

I simply deleted the dropin.cache file and twistd will find the maas-pserv now.

dropin.cache is located on /usr/lib/python2.7/dist-packages/twisted/plugins at my machines.


The following will set a static ip that network manager will respect.  I have copied this from personal ubuntu 14.04 ltsp install instructions so you may not need some of it.  I tried to modify the addresses based off your information in the linked questions.  I substituted the local nameserver IP addresses with Google's.  Modify as needed.  I also set an example domain search.

#
# set static ip
#
sudo -i
echo "" >> /etc/network/interfaces
echo "" >> /etc/network/interfaces
echo "auto eth0" >> /etc/network/interfaces
echo "iface eth0 inet static" >> /etc/network/interfaces
echo "    address 192.168.1.2" >> /etc/network/interfaces
echo "    netmask 255.255.255.0" >> /etc/network/interfaces
echo "    gateway 192.168.1.1" >> /etc/network/interfaces
echo "    dns-search internal.example.com" >> /etc/network/interfaces
echo "    dns-nameservers 8.8.8.8 8.8.4.4" >> /etc/network/interfaces
echo "" >> /etc/network/interfaces
echo "" >> /etc/network/interfaces
echo "" >> /etc/resolvconf/resolv.conf.d/head
echo "nameserver 8.8.8.8" >> /etc/resolvconf/resolv.conf.d/head
echo "nameserver 8.8.4.4" >> /etc/resolvconf/resolv.conf.d/head
echo "" >> /etc/resolvconf/resolv.conf.d/head
resolvconf -u
reboot
exit

You can also make use of the DNS_SERVER variable in the lts.conf file. For example,

[Default]
... snip ...
DNS_SERVER="8.8.8.8 8.8.4.4"
... snip ...

instead of adjusting the network manager / dnsmasq configuration.


The good people on the #ubuntu Freenode IRC channel helped a LOT. Here is what we found:

Need to follow these instructions to get apt to a steady state.
Install Emacs25 using these instructions.

Took about 2 hours to debug! Wish I could share all the pastebin.ubuntu links, but my rep is too light!


Ubuntu 16.04 desktop DNS configured over DHCP resolves only sporadically

OK it seems I found my problem. Ubuntu is using dnsmasq along with network manager to perform DNS caching. When i disable it in /etc/NetworkManager/NetworkManager.conf by commenting out dns=dnsmasq everything works fine again.
Wondering where this is coming from.

If I don't get any feedback from you guys telling me I did some terrible thing, I will accept this as the valid solution.


Regular files are all the text or data file, it can be a binary file as well. For regular files the output of ls -l would be like,

-rw-rw-r-- 1 username group 74 Nov 27 16:03 mytext.txt

In general the first place for a regular file a - should appear. In such cases if [ -f FILE ] would be appropriate.

Non-Regular files are devices, pipes, sockets, tty etc. all other that fall under "Everything is a file" philosophy as pointed out by drc. You can go through Unix_file_types for more information.

You can verify the ls -l output of some like,

crw-rw---- 1 root tty 4, 1 Dec  9 13:41 /dev/tty1
brw-rw---- 1 root disk 1, 11 Dec  9 13:41 /dev/ram11

For all the non-regular files you should use if [ -a FILE ]


System76 offers free Ubuntu stickers, which you can check with your local Ubuntu community through https://system76.com/swag/stickers


"XKB: Could not invoke xkbcomp" error when attempting to start xserver

I just had the same issue on an Ubuntu 18.04. The user had created a ~/.pam_environment with a botched PATH=... statement. After removing the file one could just log in as usual.


pgAdmin III: ERROR: function postgis_full_version() does not exist

Though perhaps a convoluted method, pgadmin III was indeed installed correctly using the above method. I found the issue... You must call the postgis_full_version() function on a database that has been PostGIS enabled.

To enable PostGIS on a database, you must execute the postgis.sql and spatial_ref_sys.sql queries on that database via command line by navigating to your <postgis>/<version>/contrib directory and executing:

psql -d <db_name> -f postgis.sql

and

psql -d <db_name> -f spatial_ref_sys.sql

If you can't seem to locate these files, you can always go to your root and use the locate command:

cd /
locate postgis.sql


error: command 'x86_64-linux-gnu-gcc' failed with exit status 1 (for lssl and lcrypto)

Try sudo apt-get install python3.X-dev where X is your python3 subversion.


How to create desktop shortcut to bash program running java

when you open that icy.sh file, you can see

    java -jar updater.jar

So you can just modify (leafpad, gedit or any other text editor)your icy.desktop file to:

   [Desktop Entry]
   Name=ICY
   Exec=java -jar '/your/path/to/file/updater.jar'
   Icon=your/path/to/icon
   Terminal=false
   Type=Application

With icy.sh set as executable and with shortcut created as:

   Exec=/your/path/to/file/icy.sh

it didnt work, like in your case... this is workaround I would use


vmware module not compiling on ubuntu 14.04

Please download VMPlayer 12 from the VMWare website.   I believe that you will find that it compiles much more nicely than the old version you are attempting to use.

The player is located at this location


Errors were encountered while processing: wps-office

From comments, run:

sudo mkdir /usr/share/desktop-directories/
sudo touch /usr/share//mime/packages/wps-office-et.xml
sudo apt-get purge wps-office


Digital Photo Professional alternative for Ubuntu?

Darktable. This is pretty much the open source counterpart to Adobe's Lightroom. It's pretty good, I've used it for some years now. It's available through the usual Ubuntu repositories.


Missing apple keyboard layout: English (International, Macintosh)

Looks like you need to make the adjustment suggested in this Ask Ubuntu answer. Once you have done that, the English (Macintosh) keyboard layout probably fits your physical keyboard.
Edit:
If editing /etc/default/keyboard proved to not be persistent, the explanation might be that there is only one user on your system and that the change was silently wiped out when you added or removed input sources in Settings.
If you set it by running this command:
gsettings set org.gnome.desktop.input-sources xkb-options "['apple:badmap']"

instead it ought to stay.
(Looks like you hit a known inconsistency where GNOME and XKB don't play well together. That's a bug, and the issue is mentioned in passing in the discussion at bug #1892014.)


That is by design.  You don't want someone looking at your password over your shoulder as you enter it.  This is common practice with almost all password entry fields out there today, not just SSH.  Some servers will show *'s when entering the password, but I know Ubuntu 16 and 18 do not by default.


How to remove first X lines from file up to the first occurrence of particular string?

You can do it using sed:

sed -n '/^INSERT/,$p' file.sql

It says print the data from the line which begins with INSERT ... to the end.

From desired pattern: /^INSERT/
To the ,
End $
Print p

To modify the file instead of viewing it:

sed -n -i.bk '/^INSERT/,$p' file.sql

It would keep the original files with .bk suffix.

To run it on all files:

sed -n -i.bk '/^INSERT/,$p' ~/path/to/sql_dir/*.sql

For example:

Foo
Bar
FooBar
INSERT Foo
Fantastic

Would become:

INSERT Foo
Fantastic


Is that possible to transfer already installed Ubuntu to a bootable USB stick?

Absolutely, Systemback provides this functionality.

To install enter the following commands in a terminal window.

sudo add-apt-repository ppa:nemh/systemback
sudo apt-get update
sudo apt-get install systemback

Start Systemback
Select 'Live System Create'
When finished 'Convert to .iso'
Burn ISO to USB using the integrated Startup Disk Creator.


Fix Ubuntu 16.04 issue with Gigabyte GA-AB350 motherboard and AMD Ryzen CPU

So credits go to @MichaelBay

Set the kernel parameter acpi=nomodeset so you can boot the live session and install the OS
Boot the installed OS and install Nvidia drivers
Remove nomodeset from Grub

With that you should be set.


Yes. Ubuntu phone/tablet images now have OpenVPN support. The configuration is a bit arduous, being a phone, but it is now usable on the images by default.


Gnome 3 - Strange black areas inside windows

Try running this in a terminal:

gsettings set com.canonical.desktop.interface scrollbar-mode normal


X keyboard layout occasionally resets itself

Ubuntu intermittently checks if there are X settings and removes them to prevent conflicts with dbus's window manager configuration.

Instead of using X settings you should configure the keyboard using dbus.


Ubtunu 12.04 x86_64 Which Proprietary Nvidia Driver for nVidia GT216GLM [Quadro FX 880M] supports brightness controls on Lenvo W510?

The problem is that drivers do not yet exist in the repo for 12.04 that support this product. Nvidia driver version 331.38 supports the Quadro FX 880M GPU as of January 27th, 2014. The driver for this product is only officially packaged for 14.04. You have four options to install this new driver, listed here in the order of recommendability:

Add the xorg-edgers PPA to your system and install the nvidia-graphics-drivers-331 package.
Add the X Updates PPA to your system and install the nvidia-graphics-drivers-331 package.
Download the Blob from the Nvidia website and install it from the .run file.
Install Ubuntu 14.04.


I have had this happen as well; usually after a fresh install of 14.04. Normally it resolves itself after a reboot (or 2, at the most). Never did find a literal fix except ... rebooting.


removing the last repeated lines in the text files


Brackets on Ubuntu 18.04 - Fonts not displaying properly

Solution:

sudo add-apt-repository "deb http://us.archive.ubuntu.com/ubuntu/ artful-updates main"
sudo apt update
sudo apt install libfreetype6=2.8-0.2ubuntu2.1
sudo apt-mark hold libfreetype6

What this code does is downgrade libfreetype6:amd64 from 2.8.1-2ubuntu2 to 2.8-0.2ubuntu2.1


Is there a keyboard shortcut to deselect a file in Nautilus?

You can use Ctrl+Space to toggle selected item on active Nautilus window.

You can also use Ctrl+ Left Arrow/Right Arrow/Up Arrow/Down Arrow to change/move the focused item (file or folder).

As a sidenote, that process is somehow cleaner with a different gtk theme than the default one (Ambiance), the Numix gtk themes for example uses a great outline to highlight focused items.

Hope it helps.


Dual booting Ubuntu 11.10 and Fedora 16 [ problem partitioning ]

You can have a maximum of 4 primary partitions on 1 hard disc (where only 1 can be active at the same time). You need to use logical partitions inside an extended partition.

Maybe an image is easier:

hda is the harddisc.
hda1, hda2, hda3 are primary and hda3 holds an extended partition with logical partitions hda5, hda6, hda7 and hda8.

Regarding:

  How do I bypass this without losing data ?

Make a backup of anything important before you do anything else. Put in on a USB stick, CD or DVD or BD depending on the hardware you have and the size of the data.


Maybe fwcutter would help

To install fwcutter:

sudo apt-get update

sudo apt-get install fwcutter

It mainly works for BCM hardware

You can also install fwcutter legacy driver if you are unable find them.  Unfortunately you will need to google it


List of wireless adapters that "just work" with Ubuntu 11.10

I bought this one LM Technologies LM006 Wi-Fi USB Nano Adapter N on someones recommendation that it "just works", and it does just that.


Sync music to Ubuntu One from media server?

As far as I know, NFS does not support inotify, which is likely used heavily for filesync with Ubuntu One. I also seem to remember that Ubuntu One doesn't sync files and folders from outside your home directory.

Your suggestion sounded best to me. Do I get an upvote for that? :)


Getting Access to your HDD to Recover Data on external hdd on to other partion

Try these Steps :

Downloading Ubuntu

if you have image of Ubuntu then skip first step :

Burning the Ubuntu Live CD

if you already have live usb disk or live cd then skip these 2 step

Starting Ubuntu

With a pen drive in your computer and your Ubuntu Live CD in your cd-rom restart your computer

If your computer prompts you, you DO want to boot from a cd. Your computer will now begin to start Ubuntu. A screen will appear asking if you would like to "Try Ubuntu" or install it. Click "Try Ubuntu".  Wait for Ubuntu to load.  From the bar at the top of the screen click "Places". Inside the drop down menu that appears click "Computer". A window will open with a list of your hard drives and other storage devices (pen drives, backup drives, CD drives etc)

Double click on your Hard Drive.

Now that you can see your hard drive you need to navigate to where your files are stored

Save data .

After that open terminal and try reset unity

Try following commands in terminal (CTRL+ALT+T)

unity --reset
unity --replace


I believe that in this guide you'll have a good explanation.

  You can change Docker's storage base directory (where container and images go) using the -g option when starting the Docker daemon.

  Ubuntu/Debian: edit your /etc/default/docker file with the -g option: DOCKER_OPTS="-dns 8.8.8.8 -dns 8.8.4.4 -g /mnt"

  Fedora/Centos: edit /etc/sysconfig/docker, and add the -g option in the other_args variable: ex. other_args="-g /var/lib/testdir". If there's more than one option, make sure you enclose them in " ". After a restart, (service docker restart) Docker should use the new directory.

  Using a symlink is another method to change image storage.

  Caution - These steps depend on your current /var/lib/docker being an actual directory (not a symlink to another location).

  1) Stop docker: service docker stop. Verify no docker process is running ps faux

  2) Double check docker really isn't running. Take a look at the current docker directory: ls /var/lib/docker/

  2b) Make a backup - tar -zcC /var/lib docker > /mnt/pd0/var_lib_docker-backup-$(date +%s).tar.gz

  3) Move the /var/lib/docker directory to your new partition: mv /var/lib/docker /mnt/pd0/docker

  4) Make a symlink: ln -s /mnt/pd0/docker /var/lib/docker

  5) Take a peek at the directory structure to make sure it looks like it did before the mv: ls /var/lib/docker/ (note the trailing slash to

  6) Start docker back up service docker start

  7) restart your containersresolve the symlink)


Ignore apt-get postinstall scripts automatically

Apt gets dpkg to extract the packages afresh each time it installs. You'll have to use dpkg directly and get it to split the process:

apt-get download <package>
sudo dpkg --unpack <package>*.deb
sudo rm /var/lib/dpkg/info/<package>.postinst -f
sudo dpkg --configure <package>
sudo apt-get install -yf #To fix dependencies


libusb-0.1.so.4 shared lib error in ubuntu 64 bit system

To install the 32-bit version, run:

apt-get install libusb-0.1-4:i386

This only works if MultiArch is enabled (maybe it doesn't if you upgraded from an older Ubuntu version). Look for foreign-architecture i386 in /etc/dpkg/dpkg.cfg.d/multiarch to check if MultiArch is enabled, and if it doesn't, run echo "foreign-architecture i386" | sudo tee /etc/dpkg/dpkg.cfg.d/multiarch to enable MultiArch and apt-get update to get the new package lists.


Solved: I installed pavucontrol (as recommended here) and discovered that Skype was connected to the "Monitor of Internal Audio Analogue Stereo", instead of the "Internal Audio Analogue Stereo" itself.

The input was easily switched within that tool, and Skype works once more. Now I just hope the change is permanent.


Limit applications that can go online when tethered

you can use gufw to set up the firewall, allowing and disallowing communications as you wish. You can also turn this on and off as desired too. To install, look for gufw in USC or type in terminal:

sudo apt-get install gufw


Got it to work!!!

Seems like I had to set Dolphin as the default file manager under 'lxsession-default-apps'. You can find it under preferences--->Default applications for LXSession.

Just replace 'PCManFM' with 'Dophin' and you should be good to go.

Good luck!!!


Found some better documented version of the labelme code with better documentation. These is the full list of options that one needs to make the apache server run correctly (modify /etc/apache2/apache2.conf)

   <Directory "/var/www/LabelMeAnnotationTool">
       Options Indexes FollowSymLinks MultiViews Includes ExecCGI
       AddHandler cgi-script .cgi
       AllowOverride all
       Require all granted
       AddType text/html .shtml
       AddOutputFilter INCLUDES .shtml
       DirectoryIndex index.shtml
    </Directory>


I'd suggest to use aptitude . It features a small semi-GUI for the terminal, with a nice way of selecting the packages you'd like to install. Here's a short how-to.

Start Aptitude; note: provide no arguments.

sudo aptitude

Optionally, press U to update the package list (same as sudo apt-get update).
By default no packages are selected for upgrade. You could expand the group of packages by pressing Enter.

You'll need to press + to mark the package for installation (or upgrade in this case). You can select whole group by doing this while the group is selected.
Press = to mark it as the current situation (revert the selection above).
To uninstall a package, press -.

Press G to go the the preview of the action about to take (notice this is in a new "tab"). In the example below I selected only the "Security Updates" - others are not upgraded.

Press G again to perform the operation, or Q to close the preview tab.

Please note that this is different from marking the packages as "on hold", it's just selective upgrading.


Squid3 Proxy Server ssl-bump blocking Web Socket connections

This is not an acl in your squid.conf?

I think you must write
acl step1 at_step SslBump1
instead of
ssl_bump step1 at_step SslBump1

Regards,
József


Maybe it's trying to mount the Windows partition but fails.

If that's the case you should configure it not to try to mount the Windows partition in /etc/fstab.


How to install multiple versions of XAMPP?

The solution is have separate directories and create a sym link to /opt/lampp

Keep 1.7.7 as /opt/lampp.1_7_7 and 1.7.1 as /opt/lampp.1_7_1 you can create a sym link to /opt/lampp. Based on the version choice you can change the sym link.

But the pain is if you have to switch versions you have delete the link and recreate a new one. So to avoid this, I found a script that can do the job.

Refer to this article (dead link, web.archive.org backup) to create the sym link

Script  can help you to:

  gives a choice of available versions of XAMPP (based on folder names
  containing them, based on the pattern shown above),
  stops the XAMPP
  server processes,
  deletes the existing lampp soft link,
  creates a new
  soft link pointing at the folder containing the the chosen version of
  XAMPP.

  Source


How to convert a Video to avi xvid with custom Frame Size?

I have found Handbrake to be a real pleasure.
https://trac.handbrake.fr/wiki/PictureSettings
He also has a ppa for Ubuntu.
https://launchpad.net/~stebbins/+archive/handbrake-releases


Where is LiveCD Ubuntu saving the downloaded files?

I found out that LiveCD stores all the data gathered on RAM and if one runs out RAM, then it spills it over to the installation device itself if it has been modified for any spare room.


Restricting Internet access of some LAN clients to a few websites using an Ubuntu gateway

The basic thing to do is to make the squid server the default gateway instead of your Internet router.

Just add an additional network card to the Ubuntu squid bringing it up to 2 network cards: 1 into your LAN and 1 into your network router. The LAN-side now gets the IP address of the default gateway (probably 192.168.1.1) and the WAN-side gets an automatic IP address from the ISP.

That way all of your network traffic passes through the squid server before going out and it can block anything. Just treat it as a normal Ubuntu machine with a firewall and I would advise not to use blacklisting, but just whitelist stuff.

The only difference is that you might need to add a few manual routes for inside your network but the default goes to squid who just drops everything that is not in the white list...

It's as simple as that!


cp does not seem to use copy on write on btrfs by default

It is a normal behavior. If you use mv, it will do it instantly. If you copy, it is supposed to be a "real" copy.


How to change vertical vs horizontal mouse sensitivity?

This may or may not work. It started as a comment, but I need formatting.

I'm not sure if it's important, but my xorg configs are in /etc/X11/xorg.conf.d/, not /usr/share/X11/xorg.conf.d. Also, you know there's a typo in that script in your link, and the last line should be EndSection? In any case, try and simplify and just have:

Section "InputClass"
    MatchIsPointer "yes"
    Option "HorizResolution" "1"
    Option "VertResolution" "1.77"
EndSection

You'd probably want it for all pointers anyway. Again, try with 10 times the values, to see if it works. You'll need to restart (X) for it to work.


Consider a kernel upgrade to 3.5.x. You should have the possibility to install linux-image-3.5.0-18-generic from the precise-updates repository.

That move solved all my USB related problems with a 'ASRock Z77 Extreme6' motherboard with Intel chipset.


How do I get an Epson 7520 (all-in-one) printer working?

I dont see any reason why this should not be possible.

The 7520 printer and scanner drivers are available from Epson themselves (search for 7520 and the OS of "linux")

Download the .deb files appropriate to you architecture - i386.deb for 32bit and amd64.deb for 64bit ubuntu.

Then install using the syntax:

sudo dpkg -i [package-filename.deb]

for example

sudo dpkg -i epson-inkjet-printer-escpr_1.1.2-1lsb3.2_i386.deb


UFW not working in 16.04 server. Refers to earlier kernel module?

It seems I have solved it. 16.04 was installed over a disk containing an earlier version and for some reason it a) did not remove earlier kernels, and b) did not install the 16.04 4.4 kernel.
solution -  I deleted all earlier kernels from /boot and all directories referring to modules for earlier kernels, and reinstalled. That got rid of the problem.


I have no problems downloading from these URLs:

http://cdimage.ubuntu.com/releases/trusty/release/ubuntu-14.04-desktop-amd64+mac.iso (desktop)

http://cdimage.ubuntu.com/releases/14.04/release/ubuntu-14.04-server-amd64+mac.iso (server)


I figured it out! After you set up your local USB or network printers, you go to the Ubuntu Software center and search "Google Cloud Print Server" and it will bring up "Server For Google Cloudprint" (or via the terminal sudo apt-get install cloudprint) and when it is complete type sudo apt-get update to update the current configuration. Then, once that is all done, type sudo cloudprint to run the application, then it should bring up a screen in FireFox or what ever browser you have, and then you make the USB printer you made with CUPS a Google Cloud Print Printer! Also keeping it as a Network Printer for you Mac and Windows devices!


Ubuntu 16.04.3 LTS Intel Graphic Drivers

I solved the issue with the answer from Reborn in the following link :

Intel Graphic Installer 2.0.2 fails on fresh ubuntu 16.04

Add PPA repository for stable mesa-utils:

sudo add-apt-repository ppa:paulo-miguel-dias/pkppa && sudo apt-get update

Install the new mesa drivers.

sudo apt-get install mesa-utils

Install the latest version of the Intel Tool

sudo dpkg -i intel-graphics-update-tool_2.0.5_amd64.deb

Now everything should be working properly.


Installed ubuntu on Win7 but no application found (no terminal, no browser ?)

If you're using 12.04, then applications can be downloaded and installed from the Software Centre (there should be a button for it in the Unity taskbar on your left).
As for upgrades, they should prompt you for it automatically, as and when updates come out.

Hope this helps :)


Where does Sound Recorder place the files it records?

Ok, I'm unsure how I managed to miss it...

~/Recordings is the answer.


This might help you.  Just press Ctrl+Alt+T on your keyboard to open Terminal. When it opens, run the command below.

sudo apt-get install linux-backports-modules-wireless-oneiric-generic
sudo reboot


Installing Windows 7 after installing Ubuntu 14.10

Just boot into the Windows disk, select the drive you wish to overwrite, and go through the normal Windows installation. It should wipe it clean and install Windows on it.

Although, in Ubuntu, it's become so simple to use that you rarely should need to mess with your disk partitions or open up a terminal, and in most cases you can get support on using the command-line here.


What guidelines should one follow when customizing their install in order to maintain an upgrade path?

One important factor in making upgrades run smooth is not to do anything which confuses the package manager. That is, you shouldn't yourself touch areas of the system which the package manager expect to be its domain. A few concrete examples.

If you compile/install programs yourself using the ./configure; make; make install method, don't put them directly under /usr. It is better to use /usr/local or /opt, alternatively (even better) to roll your own deb packages.

When you remove packages you can either do a normal removal or an explicit purge. Unless you purge the package the package manager might leave files behind under /etc, /var and so on. Do not delete these files yourself, as the package manager expects them to be there. Instead use your package manager to explicitly purge the remains of the package.

Using deb package from third party repositories should theoretically be safe, assuming they are carefully built etc. Yet, to be on the safe side you might want to consider removing those packages and/or repositories before you perform an upgrade to a new Ubuntu release.

Ok, let me see if I can add some more meat to this answer...

First of all, everything you do in your home directory is perfectly safe in regards to the package manager. It will never touch anything under /home.

(Of course, you can still cause yourself plenty of confusion by doing bad thing to your home directory. Luckily that is usually be recovered from by removing the broken configuration files from your home directory, and let them be re-created from default at the next use. Do note that the automatic re-creation of default config only goes for your personal configuration files, not the system wide stuff under /etc)

In the role of a (power) desktop user I guess the most common system wide creativity will be installing extra applications, libraries, emacs modes, etc? Again, the really important part is to always put none deb package stuff under /usr/local instead of under /usr; to use /usr/local/bin instead of /usr/bin, to use /usr/local/share/emacs/23.1 instead of /usr/share/emacs/23.1 and so on.

Once you start playing around with server daemons you will soon be confronted by the system wide configuration under /etc. While you generally can modify files under /etc, you should "never" actually remove a file or a directory there, unless it was you who created it yourself. Likewise should you be careful about yourself creating new files in there, in case they would later on collide with a configuration file the package manager want to create. That being said, there are definitely files which you can (and should) be created under /etc. On of the more common examples is defining your Apache VirtualHosts under /etc/apache2/sites-available.

There might be times when you want create files or directories under /var. While it is a completely different place than /etc, still consider the same rules about being careful and doing things on individual consideration.

In case you want to know more, it won't hurt you to take a peek at the Filesystem Hierarchy Standard (FHS) or in the Debian Policy Manual. While it might be completely overkill in answering your original question, it is still a good read.


Anyone know if 12.04 has OpenGL Aux Libraries?

Firstly, why aren't you using GLUT? The OpenGL FAQ hates AUX:

2.130 What is the AUX library?
Very important: Don't use AUX. Use GLUT instead.
The AUX library was developed by SGI early in OpenGL's life to ease creation of small OpenGL demonstration programs. It's currently neither supported nor maintained. Developing OpenGL programs using AUX is strongly discouraged. Use the GLUT instead. It's more flexible and powerful and is available on a wide range of platforms.

Long-unsupported software has a habit of not being packaged or (if it has already), being removed.
From what I'm starting to gather from reading around, GLAUX was never supported on Linux and is long-since dead on Windows.
Follow the advice of the FAQ and use GLUT (libglui et al).


WiFi icon often not appearing in icons tray

Right-click the little triangle in the tray and choose System Tray Settings. On the Display page, ensure that all categories are selected, and that the Network Management extra item is selected. On the Entries page page, ensure that visibility for Network Management is set to Auto.


Wacom Intuous tablet not mapping to single monitor

I found a bug regarding this Problem
here.
the Problem seems to be with the display output names. For me the Workaround with setting the output manually with worked:
xsetwacom --set "Wacom Intuos Pro S Pen stylus" MapToOutput 1920x1080+0+0

Well, I actually had to change the numbers around a bit, because, the aspect ratio and position of my desired display are different. But as a temporary workaround, while they are working on a solution this is OK for me.
the general idea with the numbers at the end is:
<width of projection>+<height of projection>+<offset x>+<offset y>
for me it was 3400x1440+3840+0
When you are using a different tablet, you might get a message, like this: Cannot find device 'Wacom Intuos Pro S Pen stylus'.. I was lucky enough, that I just had to switch out the S for an M (so the string was Wacom Intuos Pro M Pen stylus for me) but I don't really know where to look for the value you have to use here, when using a different product.
I hope it helps.
EDT:
I forgot: I'm using Ubuntu 20.04.1 LTS (with kernel version 5.4.0-52-generic). I'm not so sure on whether or not it's the same for other distros, but yeah, still hope, that I at least notched you in the right direction.


Boot old ubuntu harddrive luks encrypted

You don't really want to boot from the old HD, do you? Just read files/data from it?

Once the old HD is connected, and you're running your new Ubuntu (or a live ISO/DVD/USB) the "Disks" program (gnome-disks) should be a nice graphical way to see if the old HD's partitions are encrypted with LUKS, unlock/open them (assuming you have a passphrase), and then mount them.

You could use terminal tools too, like these:

And maybe your drive uses LVM, so you might need to add in commands like these too (from help.ubuntu.com's Resize Encrypted Partitions ):

sudo apt-get install lvm2 to install the lvm tools
sudo vgscan --mknodes
sudo vgchange -ay  these two should recognize/activate the lvm, I think to a new name, something in /dev/mapper/

lsblk to quickly see the drives/partitions attached
cryptsetup isLuks <device> to check if the partition/device is a LUKS volume
cryptsetup luksOpen <device> <name> to open/unlock a LUKS device & set up a mapping <name>
mount /dev/mapper/<name> /mountpoint to mount it at some /mountpoint

But "Disks" is pretty nice, when it works.


Yes, you can simply edit that line this way:

GRUB_CMDLINE_LINUX_DEFAULT="quiet splash acpi_backlight=vendor intel_pstate=enable"

And run:

sudo update-grub

Then reboot:

sudo reboot


make sure that you have the Java installed by running

java -version

If it returns an error, run this:

sudo apt-get update
sudo apt-get install default-jdk

Good luck !


There's a way to print duplex manually using gnome-manual-duplex. It's in the standard repositories and works well out of the bo with certain printers. It may need manual configuration for other printers.


This is shell specific behavior. The system to which you are logging in with ssh gives you zsh as your default shell, whereas in Ubuntu, the default shell is bash. Try it! Open a terminal and type zsh. The first time you run it, it will ask you for a configuration option. Then, presto, you have your desired behavior.

To make it permanently your login shell, open a terminal and type

chsh -s /bin/zsh

Next time you log in, zsh will be your default shell.


Set the default microphone in Kubuntu 17.04

With Kubuntu 17.04 the KDE sound settings for choosing the preferred sound device only list the PulseAudio Sound Server and are useless. Instead the user must configure the default sound source in PulseAudio.

First run pacmd list-sources | egrep "name:|device.product.name" to find out which sound sources are available to PulseAudio. The command pacmd list-sources outputs one block for each sound sources it finds. The name of the sound source is located at the top the block following the text name:. A description of the sound source is located further below following the text device.product.name.

On my setup I get:

name: <alsa_input.usb-046d_0991_xxxxxxxx-xx.analog-mono>
device.product.name = "QuickCam Pro for Notebooks"
name: <alsa_output.pci-xxxx_xx_xx.x.analog-stereo.monitor>
device.product.name = "7 Series/C216 Chipset Family High Definition Audio Controller"
name: <alsa_input.pci-xxxx_xx_xx.x.analog-stereo>
device.product.name = "7 Series/C216 Chipset Family High Definition Audio Controller"

For some reason the microphone input of my mainboard is listed twice.
I want to use the webcam microphone by default; I can change this setting using pacmd set-default-source followed by the name of the preferred recording device. In my case:

pacmd set-default-source alsa_input.usb-046d_0991_xxxxxxxx-xx.analog-mono

The setting should be permanent, that is, PulseAudio will remember it even after a restart.

It is also possible to set the default playback device in a similar way. In PulseAudio a playback device is called a "sink". pacmd list-sinks lists the playback devices and pacmd set-default-sink set the default playback device.


Updateing package by sudo command in 13.04

Try sudo apt-get -f install  then try to update again. From:http://www.linuxquestions.org/questions/debian-26/sub-process-usr-bin-dpkg-returned-an-error-code-1-a-171107/


Space Fm turned out to have these option being lightweight at the same time. I posted this an answer hoping it may be useful for someone.


How to remove or purge a kernel package manually to resolve a stuck APT/DPKG installation?

This is not a clean solution as it does not update the some generated kernel settings/files.(It skips all post-/pre- scripts & dpkg triggers)

Check the installed files using

 dpkg -L linux-image-...

Remove them manually
Remove generated RAMDisk

sudo rm /boot/initrd.img-...

Backup /var/lib/dpkg/status them open it and change its status to deinstall
Update grub menu

sudo update-grub


14.04 - Mac Mini - wireless connects but no Internet

You do not have a default gateway assigned.

Here is my routing info

Kernel IP routing table
Destination     Gateway         Genmask         Flags Metric Ref    Use Iface
192.168.0.0     0.0.0.0         255.255.255.0   U     2      0        0 wlan0
0.0.0.0         192.168.0.1     0.0.0.0         UG    2      0        0 wlan0

Note that my first line, aside from the different address, is just like yours.
It says that the other computers that start with 192.168.0 are on the wlan0 interface.
BUT if the IP doesn't match ANYTHING use the 0.0.0.0 line, and use 192.168.0.1 as a gateway to get to another network (Internet)

Fixing this would depend on how you are getting your networking information.  If it's through DHCP, then the router isn't generating the right gateway.  If you are using static information (You chose the address arbitrarily) then you need to add the default gateway.


How do I get Ctrl+Left / Ctrl+Right to jump a word again in byobu?

One solution was to switch the backend to screen. However, I had recurring issues with ctrl-right when I did that. To do that change ~/.byobu/backend to BYOBU_BACKEND=screen.

I subsequently found a much better solution using tmux from this bug. Create ~/.byobu/.tmux.conf with this value:

set-window-option -g xterm-keys on

Then ~/.byobu/keybindings.tmux with:

unbind-key -n C-Left
unbind-key -n C-Right

Now ctrl-left and ctrl-right jump one word at a time in tmux.


It's not cgroups-lite.it's cgroup-lite.So try to install cgroup-lite by running the below command,

sudo apt-get install cgroup-lite

How did i know?

If you face any E: Unable to locate package error while installing a package,then there may be a chance of mispelt the package name.you have to search for the packages availabe on that name by cutting down the last letters,

apt-cache search package-name

In your case i had cutdown -lite from the package name you mentiond.

$ apt-cache search cgroups

cgroup-lite - Light-weight package to set up cgroups at system boot
libpam-systemd - system and service manager - PAM module
ulatency - scriptable latency regulator using cgroups (client)
ulatencyd - scriptable latency regulator using cgroups (server)

So the correct package is cgroup-lite.


why do some applications exit on their own without giving notification, error, or whatsoever?

Probably a crash. If it's always the same application, you should run it from the terminal and see if error messages are printed during the crash.

Open a terminal by pressing ctrl+alt+t or typing terminal in the dash.


Preserve Permissions when adding files to a Samba share

What happens when you insert the following two lines in the share definition in smb.conf:

ea support = yes
vfs objects = catia fruit streams_xattr
map archive = No

And restart smbd:

sudo service smbd restart


Just do:

echo 'link_1234' | sed 's|_||'

When you do:

echo 'link_1234' | sed 's|_|&/|g'

you are replacing _ with _/. sed keeps the searched pattern as & so that you an use it in replacement as a shorthand, as your searched pattern is _ and replacement is &/, you are replacing _ with _/.

About the g modifier at the end, it is useful when there are more than one match and you want to do the replacement on all of them, as there is only one _ so g is redundant here.


How do I find a virus/malware embedded in an mp3?

Using malwarebytes in wine may be your solution to the problem. You can install it with wine if you do not currently have wine installed you can checkout how to install wine.

Next install malwarebytes

Install malwarebytes with wine:
Example if you installed:

mwb-setup-2.0.1500.exe

Type:

wine mwb-setup-2.0.1500.exe

To run the installer. When installed run the app by opening the unity and typing malwarebytes. Or

wine malwarebytes


Connect both HDD and SSD to the PC.

(optional) Boot Windows installation, install drivers for SSD, shutdown.

Boot PC from live cd/usb (Ubuntu will be ok).

Open gparted. Resize all partitions to smallest possible size, but leave around 100 mb of free space on each one. And move partitions closer to "left border". Apply this operation.

Open terminal. Detect which drive is your HDD and which one is SSD (see cat /proc/partitions)

sudo dd if=HDD_DEVICE bs=1M of=SSD_DEVICE - it will take some time
(for example: sudo dd if=/dev/sda bs=1M of=/dev/nvme0n1)

sudo partprobe SSD_DEVICE (for example: /dev/nvme0n1)

Probably, you'll need to expand partition table and file systems again, so you can use gparted again.

Shutdown. Remove HDD.

Try to boot again.

Next:

If everything looks ok, you can connect HDD, format it, and use as you wish.
OR Change UUIDs of HDD file systems: tune2fs /dev/sda1 -U random /dev/sda1 (probably the same for sdb if you have, etc). But don't do this with your SSD!

This operation is potentially dangerous. Be attentive with device names you're using!


How to disable Ubuntu 13.04 Unity fancy visual effects?

You can use the Compiz Config Settings Manager to change the behavior and effects of Ubuntu. If you are really adventurous you could look into this to tweak some things. Just be aware that it is a pretty advanced tool. Changing the wrong options can leave you with an unusable desktop. Unfortunately, I don't have a lot of experience with this tool so I can't give advice on which settings you could change..


Unable to find Visual Studio Code's VSCode downloaded from Ubunto Software

Thank you to all concerned. I found a solution.

Removed original download from Ubuntu Software
Found deb download link from Visual Studio Code website
Saved package to Downloads
Clicked to open and selected Install
Upon completion, checked version with Terminal Command "code -V" which returned a string commencing 1.53.1

Again thank you. I am new to Linux and to creating my own workstation, as I have always had a DBA to do it for me, so it as been a fun few days and I am almost there now. Just a couple of VSCode extensions to do and I am working again.


Right path to CPP SDK for using it in IntelliJ Idea's cpp-project

If your gcc is /usr/bin/gcc, I have set it to /usr/bin.

The only way to run is right click on main cpp file and say compile the cpp.

This compiles as well as runs the a.out file.


Issue the command:
sudo add-apt-repository ppa:ubuntu-wine/ppa

followed by

sudo apt-get update and then

sudo apt-get install wine1.8 winetricks

If you install wininet from winetricks it automatically adds the right settings so in the terminal, type:

winetricks wininet allfonts

the above command installs both wininet and several windows fonts. I'm not certain this is absolutely necessary but it shouldn't do any harm.

Finally run winecfg from the terminal or find “Configure Wine” in your desktop menu. Go to the “libraries” tab. You should see wininet( native,builtin) already listed there. If it isn't, put  it there

In the field labeled “New override for library” type in:
dbghelp
click add to put it in the list and confirm with Yes on the pop up.
click on dbghelp (native,builtin) that is now in the list
click edit
select disable
click “ok”

In the field labeled “New override for library” type in:
msvcp100
click add
click ok

You’re all set. Download and install the client you want.

EDIT: Note that the current wine package available in the ppa may vary dependent upon the passage of time and the version of Ubuntu you are running and while this answer was confirmed with wine 1.7 at the time this answer was written your mileage may vary. You can check to see what package is currently available from the PPA for your version of Ubuntu here. For detail on recent wine tests of the Battle.net launcher on Ubuntu 16.04 see here

Source: http://brockhatfield.com/2014/01/23/hearthstone-linux-wine/


Source setup not working on ubuntu 14.04

The string you entered (perhaps due to copy-and-paste) seems to be missing a close quote (').

Simply type the close quote ('), and hit ENTER


Ubuntu 16.04 SSH RSA Keys work but only if password authentication is enabled (Putty)

I had the home directory encrypted, this seems to have been the cause. I re-installed and set up SSH again and it worked fine, as soon as the home directory is encrypted, ssh keys won't work without enabling password authentication in sshd.config - must be a workaround for this but for now this works for me.


You will be able to upgrade to 16.04 LTS from 15.10 or 14.04 LTS.

It is recommended to install a stable version.

And also if you install a 16.04 beta now it will become a stable release with the standard update mechanism.

But please take in account that 16.04 is off-topic at this site untill it is released.


How to fix problems with apache2 after installing SSL certificate?

From the looks of your Apache log, there are a couple of things that should be looked at.
First, let's get rid of those Unable to load dynamic library issues by re-installing those libraries and ensuring they're enabled:

Reinstall the libraries:
sudo apt install php-xmlrpc php-xsl php-imagick

Ensure they're enabled:
sudo phpenmod xmlrpc
sudo phpenmod xsl
sudo phpenmod imagick

For the Module X already loaded in Unknown on line 0, this is probably a duplicate loading of Xdebug in php.ini.

Check that your php.ini does not have xdebug.so in either of the following lines:
extension=
zend_extension=

Confirm in your /etc/php/7.x/apache2 and /etc/php/7.x/cli/ directories that the php.ini files do not have xdebug.so specified more than once. (be sure to replace 7.x with the version of PHP that you're running. If you're running PHP 5.x, you'll need to look in etc/php5 for these directories.)

As for the SSL issues, there is nothing in the log specifically pointing to why it's not loading properly, so you may need to update your question to include an updated error.log result after fixing the above issues, assuming that solving the above issues does not resolve the underlying issue with your Apache installation


Install web site in Ubuntu Server using Samba

Assuming your document root is in /var/www/foo you need to setup a smb.conf with a section like this:

[global]
workgroup = WKG
netbios name = barserver
[foo]
path = /var/www/foo

With this settings you should be able to access the webspace from a windows computer in the LAN using \\barserver\foo

The accessing computer should be within the workgroup WKG.


Dell laptop fan very noisy in Ubuntu 16.04

There are few variations of N5110.

If you have one with Intel Graphic + Nvidia card, then Nvidia is heating up your laptop.
Solution is to install Nvidia drivers which are offered in "Additional Drivers". I am using "version 367.57 from nvidia-367".
Once installed open up "NVIDIA X server settings" application; go to "PRIME profiles" and select "Intel (Power saving mode)". Click "Quit", then Logout and Login again or just reboot. Laptop should run silently after that.

If you have one with radeon graphic card, then instructions above does not apply.


Unity - 14.04 - Set Launcher Icon Size - via command line

I was able to do this using dconf e.g. to set the launcher icon size to 64 pixels

Code:

dconf write /org/compiz/profiles/unity/plugins/unityshell/icon-size 64

To reset it to the default value, you can use

Code:

dconf reset /org/compiz/profiles/unity/plugins/unityshell/icon-size

The dconf command line utility is not installed by default - you need to install the dconf-tools package. Usually there is an equivalent command via gsettings however in this case it appears the required schema definition does not exist.

Source : http://ubuntuforums.org/showthread.php?t=2195187


Screen tearing in Ubuntu 20.04 using Intel HD Graphics 530

I too had the issue after installing focal fossa. Later, I found that a very simple display setting was causing this problem.
For me, the fractional re-scaling display setting was causing the problem. Don't use this. Use large fonts and large icons, in case you wanted a slightly bigger screen content.


Updated Ubuntu 16 to 18, doesn‘t boot properly - graphics troubles?

From the way you mentioned everything it seems that your desktop environment is missing. Why don't you try to install it again using sudo apt install unity


I've solved this one in the mean time.

1) Yes, I have identified the partitions correctly.

2) After removing the unnecessary partitions using gparted in a LiveCD (and unmounted the mounted drives), I have remade the numbering on the partitions:

sudo fdisk /dev/sdb


Another password prompt when waking from suspend

I found this solution:

First:

sudo apt-get remove gnome-screensaver

Then:

sudo killall gnome-screensaver

Suspend, resume and you will be direct on the Unity's password promt.


The OP never told us any details about their file qassam.dd, so we can only guess why they failed to mount it.

Maybe they forgot elevated permissions, sudo for the mount command.
Maybe the file system in the image file was corrupted.
Maybe it should have been loop mounted directly (not via losetup).
Maybe the partition table was GPT.
Maybe the mount command line was wrong, the OP should have looked for the device map of the partition, and used /dev/loop10p1 or /dev/mapper/loop10p1 not /dev/loop10 in the mount command.

Image file of a partition with NTFS

An image of a partition should be possible to loop mount directly, and I tested it like this,

sudo mount -o loop ntfs.img /mnt/sd1

$ echo "Hello World" > /mnt/sd1/hello.txt
$ ls -l /mnt/sd1
totalt 1
-rwxrwxrwx 1 root root 12 dec 15 23:10 hello.txt
$ cat /mnt/sd1/hello.txt
Hello World

$ losetup -l
NAME  SIZELIMIT OFFSET AUTOCLEAR RO BACK-FILE                                DIO LOG-SEC
/dev/loop0    0      0         1  0 /media/multimed-2/test/test0/temp/ntfs.img 0     512

sudo mount /dev/loop0 /mnt/lp1

$ sudo lsblk -fm /dev/loop0
NAME  FSTYPE LABEL UUID                          MOUNTPOINT SIZE OWNER GROUP MODE
loop0 ntfs         3B1CD6465B1E284E              /mnt/sd1     4G root  disk  brw-rw----

Image files of drives with partition tables

With MSDOS partition tables it was possible to mount and see the file systems via the first method of the question,

sudo losetup -f -P filename.img

list the result with

losetup -l

and mount the file system(s) with

sudo mount /dev/loop0p1 /mnt/lp1
sudo mount /dev/loop0p2 /mnt/lp2
...

With a GUID partition table it was possible to see the file systems via the second method of the question (but the first method failed),

sudo kpartx -a -v -g filename.img

Testing with an available image file,

sudo kpartx -a -v -g Lubuntu_16.04.2_amd64_persist-live_mkusb-12.1.2_7.8GB_guid-pt.img

it did not work to mount the file system(s) with

sudo mount /dev/loop0p1 /mnt/lp3
sudo mount /dev/loop0p2 /mnt/lp4
...

The loop devices could be seen by lsblk but the loop devices were hidden in the mapper subdirectory, found via find

$ sudo find /dev/ -name "*loop0*"
/dev/disk/by-id/dm-name-loop0p5
/dev/disk/by-id/dm-name-loop0p4
/dev/disk/by-id/dm-name-loop0p3
/dev/disk/by-id/dm-name-loop0p2
/dev/disk/by-id/dm-name-loop0p1
/dev/mapper/loop0p5
/dev/mapper/loop0p4
/dev/mapper/loop0p3
/dev/mapper/loop0p2
/dev/mapper/loop0p1
/dev/loop0

It was possible to mount them, for example

sudo mount /dev/mapper/loop0p1 /mnt/lp1

$ sudo lsblk -fm /dev/loop0
NAME      FSTYPE  LABEL                     UUID                                 MOUNTPOINT  SIZE OWNER GROUP MODE
loop0                                                                                7,3G root  disk  brw-rw----
├─loop0p1 ntfs    usbdata                   09BA4B4A391B6781                     /mnt/lp1    1,3G root  disk  brw-rw----
├─loop0p2                                                                                1M root  disk  brw-rw----
├─loop0p3 vfat    usbboot                   8A41-08E7                                        122M root  disk  brw-rw----
├─loop0p4 iso9660 Lubuntu 16.04.2 LTS amd64 2017-02-15-20-52-49-00                           898M root  disk  brw-rw----
└─loop0p5 ext4    casper-rw                 5bb1ca94-c265-4317-8b87-39a5486b16b9               5G root  disk  brw-rw----

$ ls -l /mnt/lp1
totalt 12
-rwxrwxrwx 1 root root 3582 feb 25  2017 backup
-rwxrwxrwx 1 root root 4592 feb 25  2017 restore

Output during testing some available img files with MSDOS partition table:

$ losetup -l
NAME       SIZELIMIT OFFSET AUTOCLEAR RO BACK-FILE                                                                                DIO LOG-SEC
/dev/loop1         0      0         0  0 /media/multimed-2/test/torios/persist/grub-n-iso/dd_ToriOS-persistent.img                                                     0     512
/dev/loop2         0      0         0  0 /media/multimed-2/boot-usb/OneButtonInstaller/xz/dd_Lubuntu_18.04_i386_persist-live_15.7GB_casper-rw_home-rw_msdos.img        0     512
/dev/loop0         0      0         0  0 /media/multimed-2/boot-usb/OneButtonInstaller/xz/dd_Lubuntu_16.04.1-persist-live-and-installed-mkusb-11.0.5_7.8GB-msdos.img   0     512

$ sudo lsblk -fm /dev/loop[0-2]
NAME      FSTYPE  LABEL                     UUID                                 MOUNTPOINT  SIZE OWNER GROUP MODE
loop0                                                                                14,6G root  disk  brw-rw----
├─loop0p1 ntfs    usbdata                   35CF6A8A4AB6BF72                     /mnt/lp1    2,2G root  disk  brw-rw----
├─loop0p2                                                                                1K root  disk  brw-rw----
├─loop0p3 vfat    usbboot                   2706-585F                            /mnt/lp2    122M root  disk  brw-rw----
├─loop0p4 iso9660 Lubuntu 16.04.1 LTS amd64 2016-07-20-12-16-02-00               /mnt/lp3    874M root  disk  brw-rw----
├─loop0p5 ext4    casper-rw                 e47ec6db-149d-4d30-98af-0419786ba250 /mnt/lp4    4,6G root  disk  brw-rw----
├─loop0p6 ext4    installed                 1acf7b6f-bb3b-4d18-90ec-454f8353c84f /mnt/lp5    5,9G root  disk  brw-rw----
└─loop0p7 swap    swap                      f2d7bd6e-eca9-48e8-a203-a1de2665d0e5            1023M root  disk  brw-rw----
loop1                                                                                792M root  disk  brw-rw----
├─loop1p1 vfat    bootgrub                  C192-D34A                                         16M root  disk  brw-rw----
├─loop1p2 iso9660 torios-live               2015-06-14-16-48-49-00                           725M root  disk  brw-rw----
└─loop1p3 ext2    live-rw                   a9843e51-4141-408b-975b-52d89eca1b28              50M root  disk  brw-rw----
loop2                                                                                14,6G root  disk  brw-rw----
├─loop2p1 vfat    lub1804-32                D4E5-7662                                         64M root  disk  brw-rw----
├─loop2p2 ext4    isodevice                 1b9f2fa2-1eab-49fa-be1c-57d38acb221f             2,2G root  disk  brw-rw----
├─loop2p3 ext4    casper-rw                 6c49bda6-68d5-44ea-9904-22b52aee2400               5G root  disk  brw-rw----
└─loop2p4 ext4    home-rw                   53476429-dc26-4395-b951-065b8c36060e             7,3G root  disk  brw-rw----


Check if dpkg is missing some libraries:

ldd /usr/bin/dpkg

If any library is missing, try to install it. If that's not the issue, then try the following:

sudo -i
mkdir /tmp/dpkg

cd /tmp/dpkg

If you are running a 32 bit version of ubuntu

wget http://security.ubuntu.com/ubuntu/pool/main/d/dpkg/dpkg_1.17.5ubuntu5.2_i386.deb

For 64 bit

wget http://security.ubuntu.com/ubuntu/pool/main/d/dpkg/dpkg_1.17.5ubuntu5.2_amd64.deb
ar x dpkg*.deb data.tar.gz
tar xfvz data.tar.gz ./usr/bin/dpkg
sudo cp ./usr/bin/dpkg /usr/bin/
sudo apt-get update
sudo apt-get install --reinstall dpkg


correct syntax to compare field with awk

The more awkish way is like this:

awk -F/ '$3 == "value" { print $3 }'

Explanation

-F specifies the field separator
Each block is executed based on the preceding condition, if non is given it is always true, the condition here is $3 == "value".
Regular expressions can be used instead if == is replaced with ~.


How to manually remove a bad email message in Evolution

It appears, you have it answered anyway, but I will add this:
 Mail in evolution is stored with folders and files in the home directory - these are in .local/share/evolution/mail/local/cur.

So if you had opened Nautilus (File Manager), pressed Ctrl+L, pasted in this and hit Enter:

~/.local/share/evolution/

It would of taken you to that directory. Some of these files have names that begin with ., so you would also of needed to press Ctrl+H to view them.

Then it is simply a matter of locating the email - the names are in this format:

1389219028.4732_4390.COMPUTER-HOSTNAME:2,

and are in date order, so if it had been a recent email it would of been easy to find. You can then open the suspect files in gedit (a text editor, so should have no effect on your system), and check the top lines against the entry in Evolution - e.g:

Return-Path: <do-not-reply@stackexchange.com>

after having found it to be the right one, right-lick and Delete it.

Note Below: Pressing Delete in Evolution won't delete the files unless it is enabled to do so - you can still view it by going to the View menu , and then pressing Show Deleted Messages  - to get rid of it properly, go to the File menu , and then press Empty Trash. This will also remove any other messages you have deleted (should do anyway).


Dell Inspiron 15 5559 problem at shutdown and logout (Intel Skylake and AMD Radeon R5 M335)

I found the solution. The problem is a driver issue with the Intel Skylake graphics chipset. You can solve it by upgrading to kernel 4.3 and upwards. For instructions to update to kernel 4.4 see here: http://ubuntuhandbook.org/index.php/2016/01/how-to-install-linux-kernel-4-4-in-ubuntu/

The only problem is that now there are some random graphical glitches appearing from time to time. It is kind of annoying, but doesn't affect functionality in any way. I guess the drivers for Skylake graphics aren't fully developed yet.


Need ubuntu with old kernel ( < 2.6.31)?

You can install the previous kernel easily, but there is no assurance that all of your system will work as it should

For 32bit-Intrepid Ibex(8.10)

mkdir kernel&&cd ./kernel&&wget http://kernel.ubuntu.com/~kernel-ppa/mainline/v2.6.30.10/linux-headers-2.6.30-02063010-generic_2.6.30-02063010_i386.deb&&wget http://kernel.ubuntu.com/~kernel-ppa/mainline/v2.6.30.10/linux-image-2.6.30-02063010-generic_2.6.30-02063010_i386.deb&&sudo dpkg -i *.deb

For 64bit-Intrepid Ibex(8.10)

mkdir kernel&&cd ./kernel&&wget http://kernel.ubuntu.com/~kernel-ppa/mainline/v2.6.30.10/linux-image-2.6.30-02063010-generic_2.6.30-02063010_amd64.deb&&wget http://kernel.ubuntu.com/~kernel-ppa/mainline/v2.6.30.10/linux-headers-2.6.30-02063010-generic_2.6.30-02063010_amd64.deb&&sudo dpkg -i *.deb

You can then select the kernel at the grub screen...


Transfer speed are superficial (Extremely high)

Depending on the specific configuration of your machine, that's most likely the disk cache at work for you...  Files that are being copied are transferred to the disk cache first and then in the background the kernel will copy it from the cache to disk.

To get your disk cache memory use:

free --human

and it'll give you something like:

             total       used       free     shared    buffers     cached
Mem:          3.8G       3.7G       136M       362M        13M       1.6G
-/+ buffers/cache:       2.0G       1.8G
Swap:         7.6G        57M       7.6G

In the above numbers, the cache is 1.6G, so, if no other reading/writing is going on, files copied to an external USB stick below that number will have high transfer speeds and once the cache is full, the copying will drop down to the effective speed of the USB stick...


How to split 7.1 soundcard outputs to 4 stereo outs with ALSA

The solution for me was to change the eightchannels pcm definition to:

pcm_slave.eightchannels {
        pcm "surround71:DX,0" # use the string identifier instead of the card id
        channels 8
}


How to check system and all configurations after failed upgrade to 16.04?

If this was a packaging issue, I'd run:

sudo apt update
sudo apt dist-upgrade

If neither of those kick out any particularly ugly errors or warnings, I'd assume the problem had been fixed. If they do throw out errors, that's the basis for fixing this.

It's possible it wasn't a packaging issue, but rather an incompatibility with the new kernel. Again, this is something you can explore by checking everything is installed correctly and then moving back onto the latest kernel.


Ubuntu does not login after resizing partitions with GParted

Before reinstalling our system you could try to reinstall the window-manager.

For a default install

sudo apt-get install --reinstall ubuntu-desktop

If this doesn't work or you don't want to try what else might be broken, save your data to an external drive by using tty with cp and maybe mount


What is wrong is that at the time that your machine was reset the data for the log file had not been written from memory (the kernel's disc cache) to disc, but the metadata recording its current size had been.  So you end up with a log file that has a few disc blocks of zero bytes, filling in the parts of the file that were allocated from free space but not in fact written to, followed by the new log data written from the next bootstrap onwards.


Boot to a Ubuntu Live DVD/USB and start gparted. Go to the Devices menu and choose to create a new partition table on your hard disk (probably /dev/sda or /dev/sdb... be careful to choose wisely... based on the disk capacity displayed). Since you say this is an old laptop, it's probably BIOS, not UEFI, so choose msdos as the partition type. This will wipe the drive. Quit gparted.

Now you should be able to double-click on the Install Ubuntu icon on the desktop to continue with the install.

Update #1:

After creating a new msdos partition table, and restarting the install of Lubuntu, the user is still having problems writing GRUB. We're going to MD5SUM/SHA256SUM the .iso file, burn it to DVD, or rebuild his USB using Startup Disk Creator, and try the installation again.

Update #2:

Lubuntu eventually got installed with the help of boot-repair. The user has to boot from the GRUB command line. Once booted, sudo update-grub also fails. There's something wrong with the GRUB files.

Update #3:

The computer has hardware problems, to include a bad CMOS battery.


Long passphrase for login and short password for screensaver

Personally I believe this is a bad idea.  You are risking exposing your high-access account and all that it accesses.

If you did have this setup at all you might well want it the other way around, so that the 'login' one is less secure... because it also needs the username, whereas the screensaver one, the one that, wuithout even typing a username will immediately get you back into the (probably prvileged) account should be longer.

Yeah it's a pain but you can also pick a password that is long, hard to crack and easy to remember.

For instacnce hjk34&*hkj567FGH might be good but something like Boston56@fishy@#### would be much easier to remember and type and would soon become 'ingrained' in the fingers.  I'd still write it down somewhere at home.

Another good option you can use is to set your screen-save for longer, say 30 or 45 minutes instead of 10... but know that you have the option to just lock it at will (ctrl-alt-del) at any time.


Command to check graphics device and graphics driver

Yes, one approach has been documented here: https://help.ubuntu.com/community/i810

You can also run this command to locate the device:

lspci | grep VGA

If you run the same command with a -k switch, it will give you the driver, too.

lspci -k


how to upgrade from Ubuntu 8.04 LTS to the latest more compatible version

You first need to decide whether having a stable platform that you wont need to update for a long time is more important to you or having the latest features.

If you decide on Long term stability you will want the latest LTS release; which at the time of writing is 12.04.  If you want the latest features its currently 13.04.

As 8.04 is really old and no longer supported I would strongly recommend you do a clean install.  You will get a much cleaner system.

Backup your personal data on at least two external devices: External USB drives, DVDs, etc.

Install a supported release letting it overwrite the existing version.  Finally restore your personal data from the backup.

Note: computers don't screw up often but when they do its easy to lose a lot of irreplaceable information so if your data is important to you keep it backed up.

Personally I have all my home computers backed up and stored in the company fire safe.  My company computers are backed up and stored in a fire safe at my home.  I would have to be very unlucky for the house and office to burn down on the same day.


Help on extending root partition on extended file system

You need to do it from live CD(USB) in this order:

If there are any data on sda3 you want to keep, back them up first.
delete sda3
select the extended partition sda2 and grow it's size to the most right.
select sda5 and grow it's size to the most right.


Why is DOSBox Emulator completely destroying my display settings?

That's because DOSBox uses SDL 1.2 - old, unmaintained library which does not work well on modern Linux. To prevent this problem, use version of DOSBox ported to SDL2, e.g. DOSBox Staging.
Available via PPA or Snap Store.


The default IM application in Ubuntu, Empathy, supports Google Talk voice and video out of the box.

In order to use it, right click on the contact and select either "Audio Call" or "Video Call".
Users that have audio capability will have a microphone next to their name in the contact list, and a little webcam if they have video support.

Google also now supports Linux officially in their client, which you can download from here.


How do I control window placement in KDE with keyboard?

More precisely:

System Settings -> Shortcuts and Gestures -> Global Keyboard Shortcuts
KDE component: KWin ▼
Quick Tile Window to the Left etc.

There is also somewhat interesting Enable/Disable Tiling, which defaults to Alt+Shift+F11. Unfortunately I could not figure out how to move tile a window so that it consumes top or bottom of the screen, but other hotkeys can be used to achieve that.


System booting into 11.10 installation after installing 10.04

ok,
  from your sourceforge results you have the following situation (correct me if I'm wrong)

You have installed 11.10 as a wubi install inside windows.

Windows has taken control of the master boot-record and thus you are no longer booting with Grub2 but with the windows boot loader - hence you are dual booting just 11.10 and windows.

Your 10.04 install is installed in partition /dev/sda5.

My suggestion would be to reinstall Grub2 - I've  reiterated what Scott has already written (adjusted for your situation)- please give some credit to Scott!

Boot from the live CD.
Mount your partition:

sudo mount /dev/sda5 /mnt

Bind mount some other necessary stuff:

for i in /sys /proc /run /dev; do sudo mount --bind "$i" "/mnt$i"; done

chroot into your Ubuntu install:

sudo chroot /mnt

At this point, you're in your install, not the live CD, and running as root. Update grub:

update-grub

If everything worked without errors, then you're all set:

exit
sudo reboot

At this point, you should be able to boot normally.

By reinstalling Grub2 - Grub will then be updated with your Lucid/Windows & Oneiric installs - you should then be able to select which O/S to boot with.


Nvidia GeForce 7100 GS drivers on Ubuntu 14.04

According to nvidia, you are supposed to be using driver 304.

First, purge any existing configuration:

sudo apt-get purge nvidia*

Then, install the correct driver:

sudo apt-get update
sudo apt-get install nvidia-304


Keyboard not working properly when remoting into Ubuntu 12.10 via tightvnc

Found a solution. While I was simply disabling the key bindings for hide all windows, I simply needed to rebind it to some arbitrary combination and the problem stopped. Hope that helps anyone with the same issue.


Problems with Zonminder and MySQL after upgrading to 16.04

I have played around a bit and was able to fix this problem ... I used This Tutorial to fix the issue. Once I added the things it mentioned and made sure the permissions were correct I was able to change settings without an error.


Yoour Sound settings image indicates that you have it set to use the digital S/PDIF connection. Change it and choose analog.
If your headphones have a Microphone attached, you will have 2 jacks, one input (pink) and one output (green). Open sound settings and plug in to the matching color starting with the output jack. You should get a headphones option to choose in the sound settings that looks like this:

The wires in these cables are very thin and flimsy. If you have an intermittant short in the wire or a poor connection you may find by wiggling it that the Headphones option appears and disappears from the Output tab.
Switching to the input tab allows for setting up the microphone (if present and attached).


20.04 Black screen, no desktop session, org.gnome.keyring.systempropter issue

This is also happening to me. I was trying to resolve unwanted printers constantly loading. After stopping the services related to that issue, I rebooted and got the dreaded black screen.
After 4 hours of searching and trying a lot of things, including the above boot repair, I ended up looking at my video drivers. At the command prompt, I entered

sudo apt remove nvidia-340

I rebooted after this and it booted to my desktop environment.
Not sure if this will help you or not, but it did work for me.


how to drop " all " ssh connections in ubuntu?

There are 2 easy ways to stop someone from being able to ssh to a machine.

1st. with iptables leave off the -s option. That denotes the source. if you use sudo iptables -A INPUT -p tcp --dport ssh -j DROP that will block all connections to port 22.

2nd. as mentioned int he comments stop and disable the openssh-server. There are several ways to do that.

You can uninstall openssh-server,

rename the init.d/ssh.conf,

run update-rc.d ssh disable, or

use the method https://askubuntu.com/a/56849/295286


Uncomplicated Firewall (UFW) is not blocking anything when using Docker

The problem was using the -p flag on containers.

It turns out that Docker makes changes directly on your iptables, which are not shown with ufw status.

Possible solutions are:

Stop using the -p flag. Use docker linking or docker networks instead.
Bind containers locally so they are not exposed outside your machine:

docker run -p 127.0.0.1:8080:8080 ...
If you insist on using the -p flag, tell docker not to touch your iptables by disabling them in /etc/docker/daemon.json and restarting:

{ "iptables" : false }

I recommend option 1 or 2. Beware that option 3 has side-effects, like containers becoming unable to connect to the internet.


Microsoft made their Windows 10 pen drives read-only to prevent using it for anything other than the intention (based on the comments on the question).


Give Apache2 write permissions network share

To give write permissions you should use the following command:

chmod 777 /home/christophe/SeagateDrive/OwncloudData/

or

chmod go+rwx /home/christophe/SeagateDrive/OwncloudData/

Changing the owner is not a good ideea in this case. You can be the ownner of a file, but you may not have read/write access to that file.


Verify integrity of installed Ubuntu packages

Part 1

sudo dpkg -S stdio.h
sudo dpkg -S stdio.h | cut -d ':' -f 1 > packages.list

source: section 5.2

Part 2

mkdir -p /tmp/archives/partial
apt-get -d -o dir::cache=/tmp -o Debug::NoLocking=1 install --reinstall  < packages.list

source: Comment from dpk on Alfonso Vila's answer

Part 3

Debs are Ar archives and can be manipulated with ar. MD5 hashes can be found using:

openssl dgst -md5 <filename>

-- I stopped here as this is where I found debsums which does all of what you want in one tidy package

sources: Wikipedia on Deb and Debsums ManPage


How to make a launcher for activate Wifi

The most convenient (and flexible) is to create a script for it:

First install gksu:

sudo apt-get install gksu

Then create the script:

#!/bin/bash

cd /home/makkekkazzo/2011_1007_RT5390_RT5392_Linux_STA_V2.5.0.3_DPO/
make
make install
modprobe rt5390sta
ifconfig enp2s0 up
service network-manager restart

make it executable, and subsequently
Create a launcher:

[Desktop Entry]
Exec=gksu /path/to/script.sh
Type=Application
Name=Update
Terminal=true

Save it as update.desktop. Also make this file executable and place it somewhere to double click.

Now when you double click the icon, you will be prompted for your password, and the script will be executed in your terminal.

OR

save the .desktopfile in ~/.local/share/applications to make it available in Dash (no need to make it executable then). Log out and back in to show it in Dash.

Notes

gksu does not notify you in case of occuring errors, hence the

Terminal=true

which will make the script execute in a terminal window.
Inside the script, we do not use the sudo in front of each command, since we run the script with sudo.
You can "pimp" your .desktop file with an icon, by adding a line:

Icon=/path/to/icon.png

more on .desktop files and their options here.


Ubuntu 18.04 LTS Bionic Beaver: Samsung Printer/Scanner M2070 via USB cannot print, can only scan

I followed these simple steps:

Direct printing with the command line
'lp -d M2070 filename'
has been successful (text-only mode).
The driver properties shows 'generic text-only printer'.
For this reason the raw printing was successful.
Go to the following URL https://www.bchemnet.com/suldr/supported.html that contains official info about Samsung Unified Linux Drivers Repository to be used.
For the M2070 Samsung multifunction printer, inside the 'Monochrome Laser Printers, multifunction (MFP-, SCX-, SF-, M & K & X (SL-, Xpress, ProXpress))' table, the 1.00.36 (driver2) is suggested.
Please refer to the same Driver (1.00.36 (driver2)) type and take in consideration the M267x PPD Series that can use the same driver.
Access the configuration printer property and select a driver for the M2070 Printer.
From the Driver list available, select 'Samsung' from the left list manufacturer and the M267x M287x Model.

Printer Test Page was successful.


Making a crontab reversed SSH connection using script

A better solution would be to make use of watchdog.  watchdog is a daemon which will watch running processes and if they exit will automatically restart them.

Install watchdog on Ubuntu 16.04

sudo apt-get install watchdog

How watchdog works

The watchdog(8) daemon will execute scripts in /etc/watchdog.d with the argument test or repair.  (see TEST DIRECTORY section of watchdog(8) man page).  Your watchdog script handles those two arguments when it checks to see if a process is running and takes an action to repair it.

You can configure watchdog by modifying /etc/watchdog.conf (See watchdog.conf(5)).

Example watchdog.d script

Take for example /etc/watchdog.d/autossh_script (which has 755 permissions and is owned by root).

  Note: you may need to customize $targetuser environment variable in the example script.  sam is my username.

#!/bin/bash

targetuser=sam

runTest=false
runRepair=false

case $1 in
  test)
    runTest=true
  ;;
  repair)
    runRepair=true
    repairExitCode=$2
  ;;
  *)
    echo 'Error: script needs to be run by watchdog' 1>&2
    exit 1
  ;;
esac

if ${runTest}; then
  #run a test here which will tell the status of your process
  #the exit code of this script will be the repairExitCode if it is non-zero
  if ! pgrep autossh &> /dev/null; then
    #autossh not running; notify watchdog to repair
    exit 1
  else
    #autossh running; no action necessary
    exit 0
  fi
fi

if ${runRepair}; then
  #take an action to repair the affected item
  #use a case statement on $repairExitCode to handle different failure cases
  su - ${targetuser} -c 'nohup autossh -f -- -NCD 8080 -i digitalOcean -R 8081:localhost:22 root@IPofDigitalOceanPC'
  exit 0
fi

I added -N to your ssh command in the example script so it only starts the tunnel but does not attempt to create a login shell.
I added -f to autossh so that it runs in the background.
The example script uses a simple pgrep pattern.  However, you can further narrow the test to a specific user or even use a pattern for the process.  See pgrep(1) for how to further customize your test using pgrep.

Configuring watchdog

/etc/watchdog.conf and /etc/defaults/watchdog are places to configure watchdog.  See watchdog.conf(5).

One thing to note is user scripts are executed once every second by default.  I recommend increasing this to at least 30 seconds unless you have a need for more realtime checking.  Adjust the interval setting in watchdog.conf.

Troubleshooting

You may need to create the /etc/watchdog.d directory before your script.

/var/log/watchdog/* contains watchdog related logs and errors.  If your script outputs to stdout or stderr then it will be written there.  On my system I notice my script executes test or repair roughly once every second.  If you use echo in your script it should only be temporary for debugging purposes only.  Otherwise, discarding output is recommended except in the case of errors.

If your script is not running at all then check the permissions: ls -l /etc/watchdog.d.


How do I enable Glippy/Parcelite's indicator applets?

Got the solution! I followed this article and 'enabled the systray for all applications'. Now I got glippy back on my systray.


Ubuntu 17.10 does not display thumbnails for videos

Install/Reinstall The Totem media player:

sudo apt-get update
sudo apt-get purge totem
sudo apt-get install totem

Clear the cache:

rm -r ~/.cache/thumbnails

The install of totem (which totem-common package is a part of) creates the thumbnail configuration file:

/usr/share/thumbnailers/totem.thumbnailer


Getting back to Ubuntu from Chrome on Pixel chromebook

Crouton doesn't give you your typical duel-boot environment, but instead creates a "chroot" environment that allows you to run both Chrome OS + Ubuntu (or another distro) simultaneously, without rebooting your computer.

You should be able to switch between the two environments via a keyboard shortcut:

Chrome OS <-> Ubuntu
Press Ctrl + Alt + Back
If this fails, try:
Ctrl + Alt + Forward, followed by Ctrl + Alt + Refresh
For Chromebooks running on an ARM processor, to swap between the two environments use:
Ctrl + Alt + Shift + Back and Ctrl + Alt + Shift + Forward

If the keyboard shortcut still fails, you can try opening a Chrome OS terminal, then typing shell into the command line, followed by sudo startunity.


Cannot get new job to run using /etc/crontab and /etc/cron.daily

Managed to work out how to do a bit of debugging by using run-parts -v /etc/cron.daily - and after a disabled the apt script (with its random upto 30 minute sleep) I found the error message for the new script:

run-parts: failed to exec /etc/cron.daily/drupal: Exec format error
run-parts: /etc/cron.daily/drupal exited with return code 1

This didn't turn up in the syslog though - which would have been helpful.

That's when I realised that I hadn't but a #!/bin/sh directive at the top of the script - fixed that, ran the run-parts command again, and all sorted.


Unfortunately, your data is most likely gone. Most likely your data drive was reformatted as a home for Ubuntu. This means that the actual Ubuntu installation could have been placed on top of other data, rendering at least some of it irrecoverable.

There is some limited good news however. There are a number of different programs that can be used to recover data. The Ubuntu DataRecovery Community Page should be a good start to recovering what can be recovered.

A final bit of warning if you choose to recover the data. Avoid using your newly installed Linux, as writes to that partition will possibly minimize the chance of successful recovery.


KWin "Walk through windows of current application" doesn't cycle

Using Plasma 5.15.4, I noticed that walking through windows of current application only walks through 2 of them. But backwards cycling does cycle through all windows, so you could use that as the standard key shortcut.


If you have dconf-editor installed:

...

and one more command line alternative:

gsettings set org.gnome.desktop.interface menus-have-icons false


How to take a screenshot using Ubuntu server 17 on port 80

As the commenters have pointed out, what you're trying to do is not very well-defined on a headless server. The Apache server does not send any "image" of the webpage (just HTML markup); the image you typically see is generated by your web browser, and the browser can render the same page differently depending on the screen size (and other things like browser version, settings, etc). If you don't have a screen, there is not a clear way to capture an image.

With that being said, one possible solution (likely the easiest one) that I've heard of is PhantomJS, a headless web browser: http://phantomjs.org/
I haven't used this method personally though; your mileage may vary.

A more general solution for doing graphical stuff on a server is to create a display for GUI applications to run on using Xvfb. This would allow you to use gnome-screenshot like you were trying to. For this, start by installing and running Xvfb:

sudo apt-get install xvfb
export DISPLAY=:0
Xvfb $DISPLAY -screen 0 1920x1080x24 -shmem -cc 4 &

Then install and run Gnome:

sudo apt-get install gnome-panel gnome-screenshot
gnome-settings &
gnome-panel &
metacity &

You'll need a browser. Any will do, but I'll use Firefox for example:

sudo apt-get install firefox

Then run the browser pointed at the webpage you want (in your case, the Apache server on localhost port 80):

firefox http://localhost &

Finally, take the screenshot just like you were trying to:

gnome-screenshot

Optionally, clean up the processes:

killall firefox Xvfb gnome-settings gnome-panel metacity

As you can see, this method is much more complicated (and resource-heavy: over 500 MB of installs), but it comes with the advantage that you can take a screenshot of any GUI application just like you would on a desktop, and it isn't limited to just taking screenshots of webpages.


Well, I had a problem with my own keyboard-shortcuts, I wasn't able to find wich one it was, so I pressed "reset all" and now it works:


Unable to install nvidia drivers. As soon as installing it it turns into login loop

For some reason I'm able to fix my problem:

after sudo service lightdm stop go crtl+alt+f1 to log in tty1
sudo apt remove nvidia* to remove every nvidia-driver you have
then sudo service lightdm restart
login your acc again
run terminal and then sudo -i. Type in your password
according to some post on this problem people recommend to sudo service lightdm stop. However, in my case, I don't do it. after i install sudo apt install nvidia-396 or any drivers from ppa:graphics-drivers/ppa that suitable to your system
after that don't reboot immediately.
go to Software and Update (search it in Ubuntu) then go to Additional Drivers. Check whether your driver has changed into your designated one. If not, install it one more time from the Additional Drivers.

after that, go to nvidia page to install cuda 9.2. Follow their instruction (recommend using the deb network installation if you have a strong internet connection)
then you can  type in terminal sudo reboot now

You will be able to login again without the loop.


sudo lshw

Should give you this info. If you want a better display, you can use sudo lshw -html > file_of_your_choice.html and open the file with your browser


What does the fourth number in the release version mean?

It is the ABI number. The following link should help answer your question:

https://wiki.ubuntu.com/KernelTeam/KernelMaintenance

From the Kernel/FAQ:

What differentiates the Ubuntu Kernel from the upstream Linux Kernel?

Ubuntu kernels are rebased against stable releases only through the development cycle, with many patches on top of the stable tag. Once the final release is made the master branch is never rebased again. While stable updates (post release) are usually applied, we sometimes make patch decisions that are counter to the stable releases.

So, the best one could say is that Ubuntu kernels are only loosely based on upstream stable. You'd have to examine the changelog to know exactly what goes into a particular kernel.

With every Ubuntu kernel release, we attempt to remain as true to the upstream Linux kernel as possible. However, there are inevitable patches which we carry on top of the upstream Linux kernel which differentiates the Ubuntu kernel from the upstream Linux kernel. This document attempts to describe the general set of patches which are carried and why: Kernel/FAQ/UbuntuDelta

What does a specific Ubuntu kernel version number mean?

The official version of an Ubuntu kernel tells you a number of things, including the base upstream version, the current Ubuntu ABI identifier and the kernel flavour. (See How can we determine the version of the running kernel? to find your current version number.)

Given a version like 2.6.35-6.9-generic this can be broken into four parts as below:

<base kernel version>-<ABI number>.<upload number>-<flavour>

The base kernel version represents the mainline version on which the Ubuntu kernel is based. The ABI number represents significant changes in the kernel Application Binary Interface. The upload number is a monotonically increasing counter for each upload of this base version. The flavour indicates which kernel configuration variant this is (See What is a Kernel Flavour?).

How can we determine the version of the running kernel?

The official version of an Ubuntu kernel is found in the /proc/version_signature file. This file contains both the full Ubuntu version of the kernel and the mainline version on which it is based. The first field is always Ubuntu, the second field is the Ubuntu kernel version, and the final field is the upstream version:

$ cat /proc/version_signature
Ubuntu 2.6.35-6.9-generic 2.6.35-rc3
$


You mentioned that you think your computer may have run out of memory. I assume that you mean disk space, and not RAM, Random Access Memory.

If you haven't encrypted your disk/data, you can boot up your computer with a live-cd, with ubuntu for example, and then you copy all of your files to another hardrive. If you don't know what I mean, search for live-cd on Google. Please respond if it worked out for you, and mark the answer as accepted. If it didn't work for you, then add it in your question, and I will try to help you.


Try running the following command in a terminal.

sudo sysctl kernel.hostname=mismis.com

/etc/hosts:

127.0.0.1       localhost
127.0.1.1       mismis.com mismis srv345.myweb.com srv345
178.162.231.61  janstone.mismis.com    janstone

# The following lines are desirable for IPv6 capable hosts
::1     localhost ip6-localhost ip6-loopback
fe00::0 ip6-localnet
ff00::0 ip6-mcastprefix
ff02::1 ip6-allnodes
ff02::2 ip6-allrouters


Try that:

sudo ln -sf /usr/bin/gcc-4.7 /usr/bin/gcc

This will recreate the missing symbolic link to the actual gcc executable (gcc in default installation is just a symbolic link to gcc-4.6).


External HDMI monitor blinking after upgrade to 16.04

Don't know what was changed in version 16.04, but I found that the blink is cause by an unsupported resolution.

I found that setting resolution/rate values using randxr is not doing any effect. Don't know the reason.

What I had to do was change resolution and rate values in the ~/.config/monitors.xml file and then restart the machine.

After that I was able to watch my movies in my tv again.

Thanks to @fakedad !!!


E:Line 1 too long in source list /etc/apt/sources.list.d/medibuntu.list

I tried removing the medibuntu list by doing

  sudo rm /etc/apt/sources.list.d/medibuntu.list

and now I can get updates  again.


Ubuntu 20.04 Chromium Snap: cannot pin Webapp shortcuts to dock

I tried a variety of things, but finally I gave up on the official Chromium build altogether. It turns out that the normal apt install just installs the snap (which seems like a jerk move, Canonical; I was trying to avoid the snap for a reason). But somebody maintains an unofficial Chromium build in a PPA: https://launchpad.net/~xalt7x/+archive/ubuntu/chromium-deb-vaapi
Make sure to follow the instructions on that page, which show you how to make the PPA version higher priority than the official one.
With that, you can get a decent experience by:

launching Chromium
going to the site you want to use like an app
picking More tools > Create shortcut
checking open as window
going to your desktop and finding the chrome-blahblahblah thing just created
right click and pick Allow Launching
move it to your ~/.local/share/applications directory
tapping on the Windows key, typing the name of your app, and launching it
now that it's in the dock, optionally right-click and pick Add to Favorites

Then at last you can have your favorite web app (e.g., Google Calendar) look and behave like a normal desktop app.