No WiFi Adaptor found, and Dummy output for sound when booting into different kernel

I have managed to install the kernels for specific version by
  installing appropriate linux-image(s) and the linux-header(s) only

In order to get the required kernel modules; that is drivers for wireless, ethernet and many more, you also needed to install linux-modules-xxx-generic as well as linux-modules-extra-xxx-generic, where xxx is the kernel version that you installed. Find out with the terminal command:

uname -r

It appears that this step was missed.

If you installed these kernels from the preferred Ubuntu repositories, you can go here and find the debs to install: https://packages.ubuntu.com/

If you installed these kernels from Ubuntu mainline, for example, here: https://kernel.ubuntu.com/~kernel-ppa/mainline/v5.6/ then you will notice that there is, in addition to linux-image and linux-headers, a package called linux-modules. Wireless, ethernet and many other drivers are included.

If you installed these kernels from some other source, please specify so that we may help you further.


We use eduroam at the university where I work; I connect to it myself when our primary wifi is being awkward.  If you've definitely removed the previous connections, try the following connection settings; this is lifted from our intranet so it's what we're telling students now:

Wireless Security: WPA & WPA2 Enterprise
Authentication: Protected EAP (PEAP)
Anonymous Identity: <leave blank>
CA Certificate: <see below>
PEAP version: Automatic
Inner authentication: MSCHAPv2
Username: <your full university username e.g. usercode@someuni.ac.uk>
Password: <your university password>

Under the CA Certificate field, select the folder Icon and navigate to the location of your certificate store.

In Ubuntu (and Linux Mint) this is located in /etc/ssl/certs

Select the QuoVadis_Root_CA_2.pem certificate.

Additionally, try waiting a little while for the password change to propagate, try your old password in case it didn't change properly (changing your password again can sometimes force these things to sync if they failed) and also see if you can connect using another device like your mobile phone, then you'll have a better idea of whether it's really your laptop or the credentials you're using.

Edit: As I've just found out, eduroam is not UK specific so my confidence in these settings being consistent across establishments is now somewhat diminished.


I need to md5 the filename of a directory of files

Maybe something like:

for i in *.html
do
    echo mv "$i" "$(md5sum <<<"${i%.html}" | awk '{print $1".html"}')"
done

${i%.html} in bash is the contents of the variable i (the current filename), with .html removed from the end. awk '{print $1".html"}' prints the first field of the output, with .html appended to it. We need this since md5sum adds a - to the output, since it is reading in from standard input:

$ md5sum <<<foo
d3b07384d113edec49eaa6238ad5ff00  -
$ md5sum <<<foo | awk '{print $1}'
d3b07384d113edec49eaa6238ad5ff00

Example:

$ for i in *.html
do
 echo mv "$i" "$(md5sum <<<"${i%.html}" | awk '{print $1".html"}')"
done
mv default.html de2b14ae7499f90736fc4a92327553a5.html
mv page.html 2adf521149526dde524f030851c7f903.html
mv post.html 0c0d03edf4e145ffd75eafb6d73deaa7.html

Remove the echo to actually move the files once you have verified the command works fine.

If you want the effect of echo -n, you can use that instead:

for i in *.html
do
    echo mv "$i" "$(echo -n "${i%.html}" | md5sum | awk '{print $1".html"}')"
done


wanna stop syncing photos from my iphone and recoup the ubuntu one space that was previously used for this

Go to U1 app on your IPhone, select Uploads tab then uncheck Auto-Upload Camera Roll. After go to Ubuntu One page and from Files tab select More on the your photo's folder and click Stop sync. Also read FAQ its kinda helpfull.


Installing Ubuntu 13.10 on Acer S7 doesn't detect operating system and then gives "??? ???" error

I had a very similar problem on my computer (same model).  It seemed like it was a problem with setting up the partions because after that error, when I would restart the installation the root and swap partitions did not show up as ext4 and swap.  I dropped to the live USB, ran GPARTED and created these two partitions for myself.  Then, I did the installation and it worked perfectly.


By design you're supposed to be able to do this, but right now you can't. It's just not implemented yet:

https://bugs.edge.launchpad.net/unity-design/+bug/878318


Ubuntu 18.10 samba share not working in non-home folder

Change this:

[Home movies]
        path = /media/diederik/<hdd-guid>/HomeMovies
;       writeable = No
;       browseable = yes
        guest ok = yes

To this:

[Home movies]
        path = /media/diederik/<hdd-guid>/HomeMovies
;       writeable = No
;       browseable = yes
        guest ok = yes
        force user = diederik

Then restart smbd: sudo service smbd restart

Reason:
The system creates /media/diederik with special permissions that allows only
diederik the ability to traverse the folder to get to what's past it. The guest user is not you so it will never get to the HomeMovies folder. force user makes the guest user appear to be you - at least for this share.

Note: Even though the guest user appears to be you the share definition will still prevent a write.

EDIT: Just noticed this comment in your original post:

  I also tried to use the explorer: right click -> Local network share
  option for the non-home folders, but this also doesn't work.

You are going to have to undo that. Can't have two samba shares of the same folder using two different methods at the same time without samba getting confused. Just go back to File Manager > Local network share > and undo the share.


How can I boot ubuntu , if I downloaded it alongside windows 10?

Hardly anyone will help you because you didn’t write which manufacturer of that computer or laptop is. Because all manufacturers have a different way of setting up UEFI secure boot. If the installation went well, you should probably add Ubuntu to the "secure boot". As far as I know Lenovo automatically orders secure boot, Acer you have to manually order ...
Or it's a banal thing like a "boot order", an attempt in UEFI or BIOS under the boot section to change the boot order, and put ubuntu above windows.
If you fail then try to find some tutorial for your laptop brand + ubuntu install.


In Ubuntu there are no drives: there are just disks and partitions and they all get mounted into the file system.

So, before you go ahead and install, boot the LiveDVD and use Try Ubuntu first!  Then none of your hard disks will be touched and you can still use the full system and try out everything and it'll be obvious to you that all of your existing data can be found under these kinds of icons:

(Enlarged for better viewing)

If you decide after a while to wipe your Windows system partition (your "C:") have a look here on how to partition a single Windows-Ubuntu dual boot disk.  Lots of the explanations in there will apply to your question.


OK, your issue is that you are mounting the NAS locally in a directory owned by root to which regular users have no access:

drwxr-xr-x 0 root root

To allow everybody to write to that directory, you need to run

sudo chmod 777 /media/iso

You should probably also mount the NAS with the users option:

sudo mount -t cifs -o credentials=/home/nicox/.smb,users //10.101.0.155/Groups/ /media/iso/


you need to edit the file /var/lib/AccountsService/users/<username-of-Vagrant> and change the valid session name under XSession= line..
[User]
Language=
Session=
XSession=gnome-xorg
Icon=/home/admin/.face
SystemAccount=false

you can use command line tools to change the line XSession=
Be-careful with the name of the session, the text shown on the gdm screen is not the actual session name.. you need to look in for the files in /usr/share/xsessions/ and/or (based on session x or wayland) /usr/share/wayland/
Warning: wrong edit will result not able to login..


Why doesn't Ubuntu 12.04 upgrade Libreoffice,as Firefox?

Actually, it's the opposite. Ubuntu is a stable system, meaning that we don't get big version upgrades for software.

The goal was to not keep upgrading Firefox. But Mozilla shortened its support so that it became impossible for Ubuntu to support older versions. That's why Firefox gets new versions even though the system is stable.

LibreOffice is supportable, so it doesn't get upgraded. However, in Ubuntu, you don't have to use new versions in order to get fixes, like in other systems. Bugs and security issues that are usually only available in new versions, are "backported" in Ubuntu, meaning that you can fix problems without changing versions.


Is there a "Hover to click" feature in Gnome Taskbar?

There is no such feature for the gnome-panel specifically.

However there is an option in gnome's accessibility settings, so that hovering anywhere for a specific (configurable) amount of time, will cause a click. Depending on your needs, this may be helpful to you.


You should name your file.conf: 20-intel_flicker_fix.conf

And place the following inside:

Section "Device"
  Identifier "Intel Graphics"
  Driver "intel"
  Option "TripleBuffer" "true"
  Option "TearFree" "true"
EndSection


How to solve incorrect RAM reading MS-7529 Motherboard, 8GB RAM

Check the speed Limitations accepted by the motherboard. You can refer to this link .


Standalone Flash Player, downloadable from Adobe website: https://www.adobe.com/support/flashplayer/debug_downloads.html (it's called "Flash Player Projector")


All the PPA in software center has been removed

This I assume is after a distribution update? if so this is the default action but they will be still in the "Other Software" tab but marked as disabled. You get to this by the edit menu in the Ubuntu Software Centre and select software sources. And check the PPAs you want to enable.

Reload the sources. Ubuntu automatically updates the version from ie. "maverick" to "natty". If a PPA has not been updated for the new version, you will receive errors when you reload the sources.  For each error go back and change "natty" back to "maverick" (or whichever version you updated from). This is usually safe as the packages generally work form version to version. Reload sources again and the PPA's should re-appear. You can wait a few weeks and try again with the newer version in case the PPA maintainer has updated his PPA.


It seems wubi bootloader file is missing or corrupted.

You can restore wubi bootloader using this guide.


You could try installing the driver from the ati website (if you haven't done so already). Follow these instructions: https://help.ubuntu.com/community/BinaryDriverHowto/ATI


JuJu charms - related to ETSI OSM MANO NFV Deployment

An OSM VNFd is a combination of a charm (for VNF operations) and a higher-level description which includes resource and service orchestration descriptions. Think of the OSM descriptor as a package that includes charms but also other metadata.

So yes, charming is a good start for OSM, but you will also want to look at the other parts and understand how they come together.


It's not a good idea to use the SSD drive as the swap space but if the life-span of the device is not a concern for you , you can manually delete your current swap partition and create a new one .

First off you have to unmount the current swap (Check your memory usage since unmounting the swap might cause bottlenecks in your RAM) :

sudo swapoff -a

Then delete your swap file (presumably it's /swapfile )

sudo rm /swapfile

And create a new swapfile in your SSD :

fallocate -l 2G /path/to/custom/swapfile/in/ssd   #Change the size to suit your needs

then change the permissions :

sudo chmod 0600 /your/swapfile

make a swap partition :

sudo mkswap /your/swapfile

and finally mount it :

sudo swapon /your/swapfile

Now you should be able to use the new swap partition.

And don't forget to change the swap file address in your /etc/fstab file to point to the new swap partition not the old one. The line containing swap should look like this :

/new/swap/location    none    swap    sw    0   0

And if you want to use the hibernation feature , you should update your grub config as @C.S.Cameron mentioned :

sudo update-grub


By default, sed does not edit the input file, it just shows the output on STDOUT.
To edit a file in place, you need the -i option of sed:
sed -i.bak 's/dog/cat/' file.txt

After the operation, the original file will be backup up as file.txt.bak and the modified file will be file.txt.
In your case:
sed -i.bak 's/dog/cat/' me

If you do not want to keep a back up:
sed -i 's/dog/cat/' file.txt

From man sed:

-i[SUFFIX], --in-place[=SUFFIX]
edit files in place (makes backup if SUFFIX supplied)


Can't fix Plymouth resolution by any means

Just in case you didn't find this tutorial, it worked for me:

http://kyleabaker.com/2010/07/11/how-to-fix-your-ubuntu-boot-screen/

Rather than fixing Plymouth, I believe this just uses framebuffer during boot with a user-chosen resolution.  It will give you more than text during boot, at least.


The package system is broken Ubuntu 15.10

The missing library is in perl-base. I hope you did not remove Perl from your system.

Because the package system is slightly broken, use an alternative way:

wget http://mirrors.kernel.org/ubuntu/pool/main/p/perl/perl-base_5.20.2-6_amd64.deb
sudo dpkg -i --force-all perl-base_5.20.2-6_amd64.deb
sudo apt-get install -f

Now check your path

perl -e "print qq(@INC)"

It should include

/usr/lib/x86_64-linux-gnu/perl/5.20.2/


You can change AUTOBIND property of /etc/default/tomcat6 to "yes" as follows:

AUTHBIND=yes

Restart your tomcat and that will enable you to use available privileged port (1-1023).


Update the PATH variable to include /usr/bin:/bin:/usr/sbin.

export $PATH=$PATH:/usr/bin:/bin:/usr/sbin

Open the /etc/environment file to save the variable permanently.

gksudo gedit /etc/environment

Make sure the PATH variable is initialized as follows:

PATH="/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin"


How to automate keyboard backlight ON at boot

Using "Startup Applications" instead of /etc/rc.local

Select the first option on your Launcher called Dash. Then type "startup" and a screen similar to this will appear:

Select the option "Startup Applications" and a screen similar to this will appear:

Select Add and this screen will appear:

Make sure you enter the command as: /usr/bin/xset led 3

I entered the comment as: Ubuntu 16.04 regular crash, Compiz segfault, error 4 in i965_dri.so, Fresh install but you don't need to.

Notes
I can't test this on my system because the Laptop's built-in keyboard and wireless keyboard both light up automatically.
You can't put xrandr commands in /etc/rc.local because it runs before a user logs in. xrandr commands can only be used after the user logs on.


My partitions disappeared after lubuntu live cd

YEAHHHHHHHHHHHHH SEEEMMM TO BE BACK

THINK  FOUND IN PUPPY FORUM :

https://www.dedoimedo.com/computers/linux-data-recovery.html

PUPPY RESCUE 2.5 SELBOOTABLE dvdISO WITH TEST.. AND PROBABLY OTHER TOOLS

ALL PARTIT BACK:)))) hurrraaaaaaaaaaaaaaaa

TEST... DIDINT WORKED IN LIVE LUBUNTU :(( I REMEBER SHOWED JUST MY CD ROMM NOTHING MORE!!!

but here in resckue puppy 2.5 test.. showed all deleted partit and recovered them:)))

https://www.awesomescreenshot.com/image/3286530/79c890eb5f1cd57c5c78d20c4e7f3115

https://www.awesomescreenshot.com/image/3286534/59d746f3344310f35128d52ec35ade12

http://smokey01.com/CatDude/ISOs/PupRescue/2.5/PupRescue_2.5.iso
https://www.awesomescreenshot.com/image/3286549/1570ed19b1a88f61a2720a00540537c9


go to setting >> Hardware >> Display
and change resolution as per your requirement.


Video player in 18.04 shows a psychedelic mixture instead of a clear video

I had the same problem when playing a MP4 video, totem/gnome-videos displays a purplish corrupted video output and I have done the following:

From the terminal sudo apt-get remove gstreamer1.0-vaapi

I have done a test and yes, the problem has been fixed now I can see the video correctly.

So the problem is gstreamer1.0-vaapi

Best Regards,


Your best best is to backup your files and important data and do a fresh Ubuntu install using the whole disk this time. Chances are when you installed you installed Ubuntu on a partition after your Windows one. In your case, re-sizing partitions can take a long time and could result is lost data, as you'd have to resize 'backwards' to take up the space that Windows once took up.


How to run the ChromePlus browser in Ubuntu?

From what I see, what you have downloaded is a compressed precompiled binary. You can start it by going to the folder where you have extracted it and double-clicking on chrome or typing ./chrome if you are in terminal. However, on my system it complains about a missing library file:

./chrome: error while loading shared libraries: libplc4.so.0d: cannot open shared object file: No such file or directory

I have managed to fix this error by copying three of these files from /usr/lib/firefox (without the .0d) extension and to /usr/lib with the added .0d extension. This is the list of files that I had to copy:

libnspr4.so
libplc4.so
libplds4.so

IMHO, I agree with SirCarlo's comment, you'd probably be better off with Chromium, the font rendering in this program feels weird on my system.


It looks like apt-key is deprecated from @Terrance.
Read this link https://www.linuxuprising.com/2021/01/apt-key-is-deprecated-how-to-add.html
In that link it states that Debian will be ending apt-key as of April 2022.  For now apt-key still works as shown in the output in the question where it stated OK which means that the key was imported.
In the future it is recommended to do the signed-by with the repositories that you are adding.
All of this answer is from the link reworded.
First, download the key in question:
For ASCII type keys do it in this form:
wget -O- <https://example.com/key/repo-key.gpg> | gpg --dearmor | sudo tee /usr/share/keyrings/<myrepository>-archive-keyring.gpg

or
curl <https://example.com/key/repo-key.gpg> | gpg --dearmor > /usr/share/keyrings/<myrepository>-archive-keyring.gpg

For non-ASCII type keys do it in this form:
wget -O- <https://example.com/key/repo-key.gpg> | sudo tee /usr/share/keyrings/<myrepository-archive-keyring.gpg>

Or you can get your keys from a keyserver like so:
sudo gpg --no-default-keyring --keyring /usr/share/keyrings/<myrepository>-archive-keyring.gpg --keyserver <hkp://keyserver.ubuntu.com:80> --recv-keys <fingerprint>

All keys will be stored in /usr/share/keyrings/ folder.  You can use those keys when you add your repo with the signed-by option to your sources.list file:
deb [signed-by=/usr/share/keyrings/<myrepository>-archive-keyring.gpg] <https://repository.example.com/debian/ stable main>

Or you can add the arch=amd64 in the same fashion:
deb [arch=amd64 signed-by=/usr/share/keyrings/<myrepository>-archive-keyring.gpg] <https://repository.example.com/debian/ stable main>

If this is helpful give thanks to @Terrance


What are the files in /dev/input/ and what they do?

This is the location where device files for your input devices are located.

Device Files: (taken from Wikipedia)

  In Unix-like operating systems, a device file or special file is an
  interface for a device driver that appears in a file system as if it
  were an ordinary file...They allow software to interact with a device
  driver using standard input/output system calls, which simplifies many
  tasks and unifies user-space I/O mechanisms.


How safe to move some system folders into ram?

No, don't run this.

Moving /var/log onto ephemeral storage is very likely to get you into basic trouble. You'll lose all log files across reboots, including the directories packages are expected to be there. If for example /var/log/cups/ does not exists, you'll probably first have to re-create the directory before you can print anything and Cups can't even burp the errors in the meantime...

/var/log/apt on another tmpfs inside one? This does not make sense.

About /var/tmp and /tmp, I find this a nice explanation:

  Since in most of the default installations the /tmp folder will be cleaned in every reboot. This is where /var/tmp comes in to play. Here, applications can expect their data to be preserved between reboots. In other words, data stored here is more persistent than /tmp.

So, stuff will probably break. Applications rely on the persistence of /var/tmp.

Common sense

Don't just do stuff people or blog posters recommend you to do.


try using the command "bash" this will open an interactive bash terminal and then use it like the normal terminal and when you are done use the command "exit" to go back to your regular terminal.


nautilus does not show external devices folder ubuntu 16.04

If a Nautilus window is showing a mounted removable device or partition, it does not get represented by the Nautilus icon in the launcher, but by the disk icon, which should have appeared below your standard launcher icons when you plugged the device in.


How can I get more granular control of Unity scaling factor?

Short answer: Not possible. This is just not supported. Maybe a future version of Ubuntu will offer more fine-grained control, but for now at least you will have to do with the values that are there.

Long answer: I very recently answered a similar question here: How do I get the value of Display -> "Scale for menu and title bars:" from the command line?

Essentially, the scaling factor is stored as a dconf setting. Run

dconf read /com/ubuntu/user-interface/scale-factor

to see what the current scaling factor is. For me this gives

{'LVDS1': 8, 'HDMI3': 8}

...where LVDS1 is my laptop display and HDMI3 is my monitor connected via the docking station (you can set different scaling factors in setups with multiple displays).

The value displayed as the Scale for menu and title bars in System Settings -> Displays is 1/8 of the dconf value of the corresponding display. So the above output means that the scaling factors for both of my displays are 1.

You could change this dconf value manually (using dconf write, see my other answer), however it must be an integer, and any integer lower than 4 or higher than 16 will confuse the system. Therefore you can only set it to values 4, 5, 6, ..., 16, which corresponds to scaling factors 4/8=.5, 5/8=.625, 6/8=.75, ..., 16/8=2. Those are the .125 steps you were seeing.


Boot Directly to Program, Launch GUI on Exit

Not so wishful if you turn the question around: instead of disabling the GUI, install the minimal system (it has no GUI) and make the login to your application work (nail that down first)

Afterwards, if you're satisfied without the GUI (automatic log out and everything) install the GUI, set the auto-log-in to a different user (who has a GUI) and just switch between two users (TTY and GUI)

I've personally never done an auto-login for a TTY user before, but I don't see why it would be impossible.


How to add a synclient command to rc.local?

As read elsewhere, you can't. rc.local executes before X starts, and synclient needs X.

A workaround is adding the command to startup applications:

bash -c "synclient string=value"

Source: http://ubuntuforums.org/showthread.php?t=1786863&page=3


No extra mouse buttons in 12.10 vmware guest

Previously answered by http://ubuntuforums.org/archive/index.php/t-1347424.html

Turns out to be a Vmware thing. vmx needed the following line:
mouse.vusb.enable = "TRUE"


I had the same problem but none of the above worked for me. Uninstalling compizconfig-settings-manager also didn't work.

In the end I found the answer here, as I was seeing the same 'Fatal: glXQueryExtensionsString is NULL for screen 0' errors in a terminal when trying to start unity. I realised I was using a proprietary ATI display driver before I upgraded from 12.04 to 12.10. I issued the commands below in a terminal:

sudo add-apt-repository ppa:makson96/fglrx
sudo apt-get update
sudo apt-get upgrade
sudo apt-get install fglrx-legacy

and then rebooted my PC. Unity then reappeared when I logged in.

There's an explanation here of why the upgrade fails in the first place. I was using an AMD Mobility Radeon HD 3650 graphics card (ATI RV635). Use:

lspci | grep VGA

to find out what graphics card you are using.


It was same happened with me but I have figured out the solution and successfully installed Ubuntu dual boot with Windows.
And remember to disable fast startup in windows. For Doing this :-

Goto Control Panel
Hardware And Sound
List item
Power Option
Choose What closing the lid does
Change Settings Which Are Currently Unavailable
At The Bottom Of The Page Uncheck Turn On Fast Startup.

Next Is To -:

Don't Turn Off the UEFI mode otherwise it would be big headache for you later.The best option is to make USB bootable in windows 10 by using Win32Diskimager.
Ubuntu 14.04 and 16.04 is signature checked OS so you need not turn secure mode off but in 16.04, in order to install 3rd parties application at the time of installation you'll need to turn secure mode off.
Reboot the PC and goto the BIOS by pressing Esc key or other key according to your system.
Turn Select UEFI mode then secure mode on/off according to your preference.
Then Restart and press Esc key and select Boot Order and select your usb.
Then you can live run it or install directly it. If you are able to do upto here then reply. I will tell you further according to the option you select. And Tell Me whether you have freed the partition space for the ubuntu?

Note - : In new Laptop if after installing Ubuntu the system may default loads into Windows. So either you can go into bios to select the boot order. The Ubuntu is displayed as seperated disk. Or Press boot menu button in the starting of your pc and select boot order as you are doing in case of selecting your usb drive.


I have a problem with compiz, openGL and everything dissapeared, no icons no nothing

Press "ctrl + alt + T" to open a terminal and type "compiz-config". You should now fix the problem from here in options, by restoring default settings of the profile you are using. Does it work?


Can't install latest version of R on ARM Chromebook

I have quite bad news: in this case, where the packages are broken for your architecture, the PPA maintainer said that it was unlikely the irregularities would be fixed any time before June. He's off on vacation, and said that "R-dev is really only for making sure development releases are building and working, and are not designed to be used for anything other than that".

However, there is an even newer version of R out, v3.3.0, and it is a fairly straight-forward installation from source code. I have here step-by-step instructions for installing from source working in a terminal, which you seem comfortable enough with and probably don't need, but for the sake of a more complete answer. The .deb files available from the r-project site seem only to be of i386 and amd64, so building it yourself seems to be the way forward.

First download the source code:

aich@compy:~$ cd Downloads/
aich@compy:Downloads$ wget https://cran.r-project.org/src/base/R-3/R-3.3.0.tar.gz

Then expand the compressed archive file and move to the build directory with:

aich@compy:Downloads$ tar -xvf R-3.3.0.tar.gz
aich@compy:Downloads$ cd R-3.3.0/

This source package doesn't have all of the resources you will need to build the language; also it does require that we resolve the dependencies ourselves. I've made a laundry list here, starting with a bare new VM of Ubuntu Desktop:

aich@compy:R-3.3.0$ sudo apt install build-essential gfortran libbz2-dev libcurl4-openssl-dev libjpeg-dev liblzma-dev libpcre3-dev libpng12-dev libreadline-dev libtiff5-dev libx11-dev libxt-dev zlib1g-dev

This list of packages should be 100% the same for your armhf install of Ubuntu as my amd64, but I was building on 16.04 rather than 14.04 (sorry didn't have a downloaded iso ready-to-go for the VM). These packages contain library extensions to the default languages on the Ubuntu install (for building new programs that can use compression, https, etc). If you are curious about what they are, query any entry with $ apt show <package name> and it will provide a short description. This is not every possible library for R, but the minimum required to have basic functionality. Now we check to see if we have all the libraries we need and if they are a new enough version:

aich@compy:R-3.3.0$ ./configure
                      (... whole bunch of ouput from Autotools checks ...)

If it stops without nice output like this:

R is now configured for <your arch here>-pc-linux-gnu

  Source directory:          .
  Installation directory:    /usr/local

  C compiler:                gcc  -g -O2
  Fortran 77 compiler:       f95  -g -O2

  C++ compiler:              g++  -g -O2
  C++11 compiler:            g++  -std=c++11 -g -O2
  Fortran 90/95 compiler:    gfortran -g -O2
  Obj-C compiler:

  Interfaces supported:      X11
  External libraries:        readline, curl
  Additional capabilities:   PNG, JPEG, TIFF, NLS
  Options enabled:           shared BLAS, R profiling

  Capabilities skipped:      cairo, ICU
  Options not enabled:       memory profiling

  Recommended packages:      yes

... then stop, and read the error above the command prompt carefully. Consider, again carefully, if having v3.3.0 instead of v3.0.2 is worth the trouble (I have no idea what the feature improvements are at all). Track down the missing dependency with a little apt-fu $ apt search <thing that seems to be missing>. But if it works, and I believe it should, build and install the software:

aich@compy:R-3.3.0$ make -j4
( ... a whole ton of output from GCC ... )

aich@compy:R-3.3.0$ sudo make install -j4

Hopefully that should be all you need to do. To get into the REPL, type $ R and away you go.


watchdog/0 process using all my CPU suddenly

Here's a quick summary of what it does:

The watchdog program writes to /dev/watchdog every ten seconds. If the device is opened but not written to within a minute, the machine will reboot. This feature is available when the kernel is built with ‘software watchdog’ support (standard in Debian kernels).

While it may seem useful, it's not really that crucial for your system's reliability, moreover it tends to cause unnecessary wakeups which in turn may lead to shorter battery performance/ You can easily disable it by adding nmi_watchdog=0 to your kernel boot parameters in /etc/default/grub.


I can't find the preferences dialog (and the hud is empty) but in between you may configure something using dconf-editor (installing the package dconf-editor) and modify some value in org.gnome.nautilus.

I use it to switch on treeview in list : org.gnome.nautilus.list-view.use-tree-view


Ubuntu is standalone OS on my laptop. Vista install failed, Ubuntu will not run now . Help

If you are going to keep Ubuntu and you have no hardware failure.
You can re-install the grub ( boot loader ) which will allow you to start up Ubuntu.

You can use your ubuntu live CD to start up the computer
follow the following steps after you open a terminal window :

1- First step: Add the boot repair repository to your system.

sudo add-apt-repository ppa:yannubuntu/boot-repair

(you will be requested to enter your root  password)

2- Second step:

sudo apt-get update

3- Third step:

sudo apt-get install -y boot-repair boot-repair

After all steps are completed and the application is installed.

Start the app GUI and hit Recommended repair if you only have one HDD installed.

I guess in laptop configuration , only one HDD is installed.

The above should get you started if there is not hardware failures.


You could use less to tail a file. Just type 'tail ' and press shift+f to start tailing it. Ctrl+c to break out of tail while remaining in file. You can type forward slash to do a search forwards in the file, and ? to search backwards in file. Both searches will highlight search terms.


How do I downgrade gracefully from gnome3

I was able to fix it up! Here are my steps:

re-enable extra repos.
ppa-purge those repos and make sure to delete ALL affected packages.
apt-get update && apt-get dist-upgrade
apt-get install ubuntu-desktop gdm

And that should be it. Some of my apps were uninstalled, but all the config data was intact and everything is back to normal now!


How can I install Ubuntu without an internet connection?

I doubt there are any differences between Ubuntu versions, that make one more suitable than another for slow Internet connections.

I think Debian has some versions on several disks that include more packages.

Ubuntu comes on a ~700 MB ISO, which can only hold so many packages. Even like that, it is not trivial to install from the Ubuntu CD.


Upgraded to 12.04 and now the WiFi applet doesn't show wireless connections to connect to

The problem might be that your Wireless Card isn't being detected, or needs restricted drivers to work properly.

Try to connect thru ethernet to the internet, open a terminal window and type:

sudo apt-get update

and then:

sudo apt-get upgrade

it updates your system.

Then, go to System Definitions > Hardware and open Aditional Drivers

It should open a window with the restricted and opensource drivers for your wireless board.
You just have to select and activate the one that you want.


how to get a list of folders and number files in each folder side by side, in the current directory?

Here is one relatively slow solution, that provides a nice output :) Place the following function at the bottom of your ~/.bashrc file. Then open new terminal window or do source the run commands file: . ~/.bashrc.

count_in() {
    # set the current directory as default value
    local paths="$PWD"; echo
    # read the user's input as array when it is provided
    [[ ! -z ${@+x} ]] && local paths=( "$@" )

    # loop over the user's input
    for path in "${paths[@]}"
    do
        # test whether this is a directory
        [[ ! -d $path ]] && { echo -e "'$path' is not a directory.\n"; break; }

        # output color table header for each top level directory
        printf '\e[1;34m%-6s%-6s%-6s%s\e[m\n' "total" "files" "dirs" "analyzed directory"
        # analyse the top level data
        total=$(find "$path/" -mindepth 1 -maxdepth 1 | wc -l)
        files=$(find "$path/" -mindepth 1 -maxdepth 1 -type f | wc -l)
        dirs=$(find "$path/" -mindepth 1 -maxdepth 1 -type d | wc -l)
        # outpot the top level data
        printf '%-6d%-6d%-6d%s\n' "$total" "$files" "$dirs" "$path"

        # output color table separator for the inner directories
        printf '\e[1;96m%-6s%-6s%-6s%s\e[m\n' "total" "files" "dirs" "sub dir name"
        # for each inner directory
        while IFS='' read -r dir
        do
                # analyse a inner directory's data
                total=$(find "$dir" -mindepth 1 -maxdepth 1 | wc -l)
                files=$(find "$dir" -mindepth 1 -maxdepth 1 -type f | wc -l)
                dirs=$(find "$dir" -mindepth 1 -maxdepth 1 -type d | wc -l)
                # outpot the inner directory's data
                printf '%-6d%-6d%-6d%s\n' "$total" "$files" "$dirs" "$(basename "$dir")"
        done <<< $(find "$path/" -mindepth 1 -maxdepth 1 -type d -print)
        echo
    done
}

Then use the count_in function as shell command:

count_in  # will analyse the current directory
count_in  /path1 /path2

Sample output:

spas@Desktop:~$ count_in Pictures ~/Videos 'Something else'

total files dirs  analyzed directory
9     3     6     Pictures
total files dirs  sub dir name
19    19    0     Life Hacks
6     6     0     GIF
55    54    1     Wallpapers
20    18    2     Avatars
173   31    142   Photos
3     2     1     Icons

total files dirs  analyzed directory
6     0     6     /home/spas/Videos
total files dirs  sub dir name
66    0     66    Movies
11    0     11    Documentary.and.Conspiracy
7     7     0     .fun
16    2     14    Science.and.SciFi
2     2     0     Fun
2     1     1     Audio.Books

'Something else' is not a directory.


Fake raid is accessed with the dmraid utility, not mdadm.  It should also work out of the box with recent Ubuntu releases.  See http://wiki.ubuntu.com/FakeRaidHowto for more information, though much of the how to part does not apply with recent releases, since as I said, it now just works automatically.


After upgrading to 18.04 from 16.04, I am unable to use nautilus or use the terminal or listen to any audio and my internet speed has reduced

If anyone else has this issue, the surefix is to downgrade to 16.04, or in case of specific programs, replace them with something else as I used Nemo instead of Nautilus and Terminator in place of gnome-terminal. There is no fix for the audio issue that seemed to work, so you might want to back up all your data and just re-install all the OS.
Following the regular procedure of installation did the trick for me.


MyGica S2870 HDTV Stick: how to configure it?

Issue closed: apparently it can't be done. There are no drivers for that device. Only the S870 HDTV works for linux. Thanks.


Videos which are converted in Linux do not play in mobile browser

Have a close look at this document for android developers:

Supported Media Formats

Note that this gives only baseline settings and  any given mobile device might provide support for additional formats or file types not listed in the table.

Based on this it looks like your choice of video codec and settings for this codec are acceptable but you would be better to specify aac for the audio codec in your commandline. This would hopefully allow for a wide range of devices with successful playback.

A suggested commandline for FFmpeg would be:

ffmpeg -i input \
        -c:v libx264 -preset slow -crf 22 \
        -profile:v baseline -level 3.0 \
        -movflags +faststart -pix_fmt yuv420p \
        -c:a libfdk_aac -b:a 128k \
        output.mp4

Some points for this choice of commandline:

For the greatest compatibility with a wide range of devices it is recommended to use -profile:v baseline -level 3.0
It is an idea to add -movflags +faststart if your file is going to be displayed online, with this setting it should start playback before fully downloaded
Use -pix_fmt yuv420p to allow playback on a wider range of devices
libfdk_aac gives better AAC sound than the native FFmpeg AAC encoder (when this encoder was still marked 'experimental')

I have provided a working sample here for testing purposes using this commandline.


How to view multiple files in single terminal?

If you have for example /var/log/syslog, /var/log/auth.log log files, you can view them both in one terminal by executing tail -f command .

Open terminal and add the following command:

tail -f /var/log/syslog  /var/log/auth.log

The output:

==> /var/log/syslog <==
Mar  4 17:44:15 client AptDaemon: INFO: Quitting due to inactivity
    Mar  4 17:44:15 client dbus[815]: [system] Activating service name='org.debian.apt' (using servicehelper)

==> /var/log/auth.log <==
Mar  4 16:17:01 client CRON[13628]: pam_unix(cron:session): session opened for user root by (uid=0)
Mar  4 16:17:01 client CRON[13628]: pam_unix(cron:session): session closed for user root


How can I see which is my boot partition?

Boot partition

In order to find the boot partition I would use the command df /bootfor an installed Ubuntu system (standard Ubuntu, Ubuntu Server and the community flavours Kubuntu, Lubuntu ... Xubuntu),

$ df /boot
Filesystem     1K-blocks     Used Available Use% Mounted on
/dev/sda8      103162996 30558020  67341528  32% /

or if you want a clean output with only the partition,

$ df /boot | grep -Eo '/dev/[^ ]+'
/dev/sda8

Boot partition and EFI partition in UEFI mode

In order to find the boot partition and the EFI partition in an Ubuntu system booted in UEFI mode (both are use during boot),

$ test -d /sys/firmware/efi/ && echo efi || echo bios
efi

$ df /boot
Filesystem     1K-blocks    Used Available Use% Mounted on
/dev/sda2      303017780 3281532 284320780   2% /

You can use fdisk (as you have been trying)  or parted to find the EFI partition,

$ sudo fdisk -lu|grep -i efi
/dev/sda1      65535   1048559    983025   480M EFI System

$ sudo parted -ls|grep -i efi
 1      33.6MB  537MB  503MB   fat32           EFI System Partition  boot, esp

Parted does not provide the drive letter on the same line as the partition number, but you can use the full information and your eyes,

$ sudo parted -ls
Model: WDC WD32 00BEKT-00PVMT0 (scsi)
Disk /dev/sda: 320GB
Sector size (logical/physical): 512B/512B
Partition Table: gpt
Disk Flags:

Number  Start   End    Size    File system     Name                  Flags
 1      33.6MB  537MB  503MB   fat32           EFI System Partition  boot, esp
 2      537MB   316GB  315GB   ext4
 3      316GB   320GB  4161MB  linux-swap(v1)


How can I increase space in /home, Ubuntu 14.04

While you can resize the partitions, which is tedious (end an error could be disastrous), you can create folders in your home directory that are actually present on / (either via links or via bind mounts):

# First make directory in `/` to hold your data:
sudo mkdir -p /var/home-stuff
sudo chown $USER:$USER /var/home-stuff

Then either make a link:

ln -s /var/home-stuff ~/folder-in-root

Or bind-mount it to a folder in your home:

mkdir -p ~/folder-in-root
sudo mount -o bind /var/home-stuff ~/folder-in-root
sudo chown $USER:$USER ~/folder-in-root

(You can make this bind permanent by adding an entry to /etc/fstab.)

Now anything put in ~/folder-in-root will actually occupy space in /.


Is there an environment variable that is set for Unity?

Ubuntu 11.10

Ubuntu session (compiz/unity)

DESKTOP_SESSION=ubuntu
GDMSESSION=ubuntu
XDG_CURRENT_DESKTOP=Unity

Ubuntu 2D session (metacity):

DESKTOP_SESSION=ubuntu-2d
GDMSESSION=ubuntu-2d
XDG_CURRENT_DESKTOP=Unity

Gnome session (gnome-shell):

DESKTOP_SESSION=gnome-shell
GDMSESSION=gnome-shell
XDG_CURRENT_DESKTOP=GNOME

Gnome Classic session (metacity):

DESKTOP_SESSION=gnome-classic
GDMSESSION=gnome-classic
XDG_CURRENT_DESKTOP=GNOME

Gnome Classic no effects session (metacity):

DESKTOP_SESSION=gnome-fallback
GDMSESSION=gnome-fallback
XDG_CURRENT_DESKTOP=GNOME

Ubuntu 11.04

Ubuntu session (compiz/unity):

DESKTOP_SESSION=gnome
GDMSESSION=gnome

Ubuntu Classic session (compiz):

DESKTOP_SESSION=gnome-classic
GDMSESSION=gnome-classic

Ubuntu Classic no effects session (metacity):

DESKTOP_SESSION=gnome-2d
GDMSESSION=gnome-2d


Group 'libvirtd' does not exist while installing QEMU-KVM

The issue is about the name of the group.
On Ubuntu, the group name should be "libvirt" ...without "d".

so your command should be:

sudo adduser `id -un` libvirt


If you have a CD/DVD drive it's easier to burn a Ubuntu CD from an ISO image and use that to install - https://releases.ubuntu.com/20.04/
USBs are a bit unreliable. UNetBootin is the best option in my humble opinion https://unetbootin.org/
Insert your medium (USB or CD). Restart, and press whatever function key you need to enter the BIOS, probably F2. Go to 'Boot Options' and move the medium you are using to the top of the list. Exit the BIOS and you should be good to go.
The Ubuntu installation medium will give you the option to wipe the disk


Is there anyway I can play a video on login

Add the command totem --fullscreen /path/to/video to your startup applications (or replace totem with your video player of choice).


How to keep SSH server running with laptop lid closed

If you have all your power management settings in the OS right, it could be a setting in the BIOS that kills particular devices when the lid is closed.  I would check that first.

If you wanted to see that, you could run an infinite ping command in terminal and check wireshark output on the device your pinging for ICMP traffic.


Can I click away notifications (notify-osd)?

Short answer: no. By design you are unable to close them (with a click, at least).

But if that really annoys you I have read sometime ago an article on WebUpd8 showing how to install a patched NotifyOSD version and a configuration tool to make them clickable. Those packages are provided through a PPA, so the usual pitfalls on using them apply(1).

Those PPA's have packages to Quantal, so if using a PPA is ok to you give it a try. I personally have never used them, so I cannot tell how stable they are or not. If something goes wrong you can use ppa-purge to revert the changes.

Configurable NotifyOSD Bubbles For Ubuntu: Move, Close On Click, Change Colors And More ~ Web Upd8

(1) Are “PPA's” safe to add to my system, and what are some “red flags” to watch out for?


Very weak wifi signal on my ubuntu 14.04 LTS running Qualcomm Atheros Device [168c:0042] (rev 30)

Try a newer backports first
wget https://www.kernel.org/pub/linux/kernel/projects/backports/stable/v4.4.2/backports-4.4.2-1.tar.gz
tar -zxvf backports-4.4.2-1.tar.gz
cd backports-20151120
sudo make uninstall

Reboot
cd backports-4.4.2-1
make defconfig-ath10k
make
sudo make install

Reboot and see if it is any better, if it isn't I would want to look at the wireless card to see if the antenna(s) are still attached

After a kernel update you will need to
cd backports-4.4.2-1
make clean
make defconfig-ath10k
make
sudo make install

Reboot


updatedb & locate command problem - Files from external hard drive are no longer indexed after rebooting

Files from your external harddisk are not indexed because updatedb is configured to not index anything under /media, which is where external storage is usually mounted. This configuration is set in the file /etc/updatedb.conf. Specifically the entry /media in the PRUNEPATHS line.

Some ideas how you can make updatedb to index your external drive:

1. Mount the external drive unter /mnt.

If your external harddisk is supposed to be mounted permanently then I suggest to configure it so that it is mounted under /mnt instead of under /media. That can usually be done by editing /etc/fstab. Search for "fstab" to learn about that. You will need sudo rights to edit /etc/fstab.

2. Create a dedicated database for your external harddisk and query that on demand.

The following command will create a dedicated database:

updatedb -l 0 -o ~/.externalharddisk.db -U /media/externalharddisk

This will create the database in the hidden file .externalharddisk.db in your home. You do not need sudo for that command. Execute the same command again to keep the database updated. Carefull: if you run that command while the external harddisk is not mounted then updatedb will think the files are deleted and will empty the database.

You can set up a script to automate that task. Search for "cronjob" to learn how to do that. Note: you can set up a user cronjob as user. You do not need sudo rights to set up a user cronjob.

The following command will query the database:

locate -d ~/.externalharddisk.db searchterm

You can also query the dedicated database and the default database at the same time:

locate -d ~/.externalharddisk.db: searchterm

The colon at the end followed by nothing means to also search in the default database.

You can make an alias for easier use. Put the following line in your .bashrc:

alias locate-external='locate -d ~/.externalharddisk.db:'

Now you can use locate to search only the default database and locate-external to also search in your external harddisk.

3. Remove /media from PRUNEPATHS

Note: I do not recommend this! This is because of the way updatedb works. If updatedb runs while the external harddisk is removed then all entries pointing to the external harddisk will be removed from the database. If updatedb runs while the external harddisk is connected then entries pointing to the external harddisk will be added again. Since updatedb is running regulary in the background you can never be sure whether the files from the external harddisk are currently indexed or not.

Furthermore: if you remove /media from PRUNEPATHS, this behaviour will also apply to any other external storage you happen to have mounted while updatedb is updating the database.


How can I stop my Samsung NC150+ from thinking it's american and no longer being able to connect to wireless networks set to channel 12 and 13

I had the same problem but i solved it by reading this post : http://hmh-ev.dyndns.org/mywiki/wlan
Sorry for my bad English.
I hope this info can be helpful
Thanks
John..


Copying contents of a small partition over contents of a larger one using GParted

I don't know if GParted would solve the problem (copy/paste partition without changing the size). But with the help of the rsync command I was able to copy all the files from the source partition to the destination partition while  preserving the size of the destination partition. Specifically:

sudo rsync -Hav /media/ubuntu/casper-rw1/ /media/ubuntu/casper-rw2/

I'd recommend to precede it by "dry run" (the -n option) and save the output in a log file, in case the rsync command outputs error messages.


I have found the solution.

Linux uses system dependent UUID's on the disks and in Grub.
This is why my second pc does not boot after the restore.

Step1: Install all needed extra applications like CLAMAV / CLAMTK / LibreOffice / ... on a clean Ubuntu

Step2: Use remastersys to create a backup of your system that can be restored on any kind of system.

wget -O - http://www.remastersys.com/ubuntu/remastersys.gpg.key | sudo apt-key add -
deb http://www.remastersys.com/ubuntu precise main
apt-get update
apt-get install remastersys
apt-get install remastersys-gui

Step3: Start remastersys and select backup. This creates a live boot cd which is saved in ~/custom.iso

Step4: Install UNetbootin to create a bootable USB stick with this custom image.

Step5: Install a new system with the new USB stick.

Now you have a system independent USB imaging restore stick.

Another way is to use FOG.

FOG is a Linux-based, free and open source computer imaging solution for Windows XP, Vista and 7 that ties together a few open-source tools with a php-based web interface. FOG doesn't use any boot disks, or CDs; everything is done via TFTP and PXE. Also with fog many drivers are built into the kernel, so you don't really need to worry about drivers (unless there isn't a linux kernel driver for it).

You can just create an image of an Ubuntu system and restore it on any other device.
No need to wory about UUID's this is all handled by FOG.


Connect desktop to laptop via ethernet crossover to use laptop Wifi connection

First of all, use a different subnet for the LAN.

Desktop: 192.168.2.2
Notebook LAN: 192.168.2.1

On the desktop configure your notebooks LAN ip address to be the default gateway.

On the notebook, enable IP forwarding:

echo 1 > /proc/sys/net/ipv4/ip_forward

You will need to edit /etc/sysctl.conf and change the line that says net.ipv4.ip_forward = 0 to net.ipv4.ip_forward = 1 to make this change permanent.

On the notebook, configure NAT for traffic coming in via the LAN interface (lets call it enp14s0) to go out via the wifi interface (lets call it wlp7s0)

/sbin/iptables -t nat -A POSTROUTING -o wlp7s0 -j MASQUERADE
/sbin/iptables -A FORWARD -i wlp7s0 -o enp14s0 -m state --state RELATED,ESTABLISHED -j ACCEPT
/sbin/iptables -A FORWARD -i enp14s0 -o wlp7s0 -j ACCEPT

That should do the trick.


Data recovery from erased external HDD NTFS partion

Probably the most powerful recovery software for most tasks is Testdisk which is free and open source and can be found in Ubuntu's software catalog, but can also be run from Windows or Mac as well.

Its interface is relatively complex but its recovery is top-notch - in case of accidental formatting or destroying of a partition you probably want to use one of its advanced modes where it can recognise a destroyed partition:

This is the exact procedure to follow for doing this for an NTFS partition.

Teskdisk's "simple" mode will use a more naive recovery type that doesn't necessarily take the partition format into account and therefore doesn't necessarily recover fragmented files or certain file types, or get the folder structure.  So you want to follow this NTFS based advanced recovery if it works for you as it will be much better.

If too much of the NTFS structure such as the master file table are corrupted or missing, then you may not be able to recover with this method and you may need to use the more naive methods in Testdisk (or as recommended in their documentation, use photorec, also open source).  Hopefully you don't need to resort to this as it can be very patchy to recover based on file signatures.


Battery level indicator on Lenovo Ideapad 330 15ICH

There's a problem with recent kernels (>=4.18 I think) recognizing the battery in the Lenovo Ideapad 330 15ICH. It has been fixed in kernel 5.0, so you can solve the problem in two ways AFAIK:

1) Installing Ubuntu 18.04.0 or 18.04.1 since they use kernel 4.15 which works fine with this computer. Only problem is the touchpad behaves a little bit uncontrolled sometimes.

2) Using a newer kernel like 5.0, everything works fine including the touchpad. I tried it in Debian 10.0 "Buster" installing the kernel from the experimental repository. Supposedly it should also work in Ubuntu 18.04 if you update the kernel >=5.0. Package linux-generic-hwe-18.04-edge provides kernel  5.0.0.15.71

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

https://packages.ubuntu.com/search?suite=all&section=all&arch=any&keywords=linux-generic-hwe&searchon=names


How to disable Always on Visible Workspace

As Sergiy Kolodyazhnyy said, "Right click on the window's top panel and uncheck that option".
However, if you have used some automated means to make that option the default, you will have modify that.


I have excessive Tearing on Flash Video Playback when i don't use compiz , on ubuntu 12.04 i dont have tearing

I used cinammon and i have no tearing anymore !
Plus because i dont use compiz i have full fps on 3d games (on sauerbratten i have 200+fps)
and i can play trine 2 in full resolution 1980x1080 full detail and the games runs very smoothly.


Apply graphic EQ to audio out,headphone jack,ubuntu 18.04

I use PulseEffects, which is pretty good (IMO). Details of how to download and install it are found here. It's also now available to install the package directly from Ubuntu Software.


With 4GB of RAM, you are on the low-end of the recommended specs, as seen here: https://help.ubuntu.com/community/Installation/SystemRequirements

  From 17.10 onwards the desktop uses GNOME Shell. In order to run these
  environments the system needs a more capable graphics adapter – see
  more here or below: ... 4096 MiB RAM (system memory) for physical
  installs.

As noted in the comment of the other (now (un)deleted(?)) response,free isn't a great indication, as Linux will use all of the RAM you give it. A better idea would be to see what is using the RAM.

I would suggest using a tool like "htop" to help you track resource usage among specific applications to see if that can help you pin down areas of improvement.


I believe 2.2 is still in beta. I have beta version and its running great, but beware its deemed "unstable".

Here is the dev ppa for docky beta, ppa:docky-core/ppa

To install it go to software sources, under "other software" add this line: ppa:docky-core/stable ,and update.

or type this into terminal:

   sudo add-apt-repository ppa:docky-core/ppa

   sudo apt-get update

   sudo apt-get install docky


Some older models don't support USB boot at all. This might be the case for your laptop, if it's old. You can check by entering the BIOS Setup (not the BIOS boot menu), and looking at the boot order. If there's nothing there for USB or "external drive" (or similar), it probably does not support booting from USB devices.


How to disable/enable combination keys (alt+space, alt+F10)?

Alt+Space by default is used to Activate the window menu

Alt+F10 by default is used for Toggle maximization state

You can change or disable these shortcuts in System Settings.

In Ubuntu 17.10 Desktop:

To disable these shortcuts, just click on one of them and press the backspace key.

For Ubuntu 16.04 the solution is same, but there is no defined default shortcut for Alt+F10


As you want to make this as user and not root, you will also need the dependencies available to the session.

Package freetype2 was not found in the pkg-config search path.

Try downloading and adding the freetype2 package to your projects directory.


How to show new Slack messages in GNOME notifications?

As I understand, this is not currently possible, and is due to a mismatch between how Electron (the framework the Slack app uses on PCs) performs notifications, and how FreeDesktop Notification Spec defines behavior of certain notifications.

The same issue also exists with other Electron apps, such as Mattermost.


This can happen because of Drivers

which Version of Ubuntu are you using ?  which one you were before ?

if "Ubuntu Logo" goes off and the mouse cursor keeps "appearing disapearing" (it means it already booted!)
 if you want to reinstall ubuntu , but keep all the data
Press CTRL + Alt + F3 . Now you are in Shell mode, you can Login and
this will reinstall ubuntu without losing data

  sudo apt-get install --reinstall ubuntu-desktop

If it doesnt go past the Loading Logo , you will need a Live ubuntu image to enter in terminal.

Please post more info about the issue


If you don't mind installing Windows on your computer there is a way of doing this.
As you said, the pairing happens over USB and it's only possible on Windows. What you can do is to pair the keyboard on Windows and transfer the pairing information to Linux. There's plenty of information out there on how to "dual-pair" or how to make Bluetooth devices work in "dual-boot" environments.
This worked for me: http://console.systems/2014/09/how-to-pair-low-energy-le-bluetooth.html on Ubuntu 18.04, the only different thing I had to do is to add an additional key not mentioned in that guide (but mentioned in the comments): IRK and set the enclave size to 16.
Here's how my info file looks like, for reference:
[General]
Name=BTLE Keyboard Fingerprint ID
Appearance=0x03c1
AddressType=static
SupportedTechnologies=LE;
Trusted=true
Blocked=false
Services=00001800-0000-1000-8000-00805f9b34fb;00001801-0000-1000-8000-00805f9b34fb;0000180a-0000-1000-8000-00805f9b34fb;0000180f-0000-1000-8000-00805f9b34fb;00001812-0000-1000-8000-00805f9b34fb;d4e3e3eb-a4ae-4193-bbf8-c769980abfe0;

[DeviceID]
Source=2
Vendor=1118
Product=2067
Version=274

[IdentityResolvingKey]
Key=40DA574571378A18D19EECB0B6814F2D

[LocalSignatureKey]
Key=9514799E99500FAACE427153D3345C63
Counter=0
Authenticated=false

[LongTermKey]
Key=467D87EB169591378DB06F3E14C43FFD
Authenticated=0
EncSize=16
EDiv=41809
Rand=8310545922518117455

[ConnectionParameters]
MinInterval=6
MaxInterval=6
Latency=60
Timeout=200

EDIT - Problem Solving:
In case you don't have a CSRK key from the Registry Export, leaving it out works just fine.
If you still have connection problems, run psexec -s -i regedit.exe, navigate to HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\BTHPORT\Parameters\Keys and take the decimal value displayed in regedit.exe.


How can I prevent X windows from running when I boot Ubuntu 12.10?

You should disable GDM, the GNOME Display Manager:

sudo update-rc.d -f gdm remove

When you restart your computer, you’ll be presented with a text-mode login prompt instead of the graphical environment.

Run X.Org:

If you want to run the graphical environment, all you have to do is type the following command from the prompt, making sure to run it as your normal user account.

startx

Enable X.Org:

sudo update-rc.d -f gdm defaults


How to view Keyboard Shortcuts cheat sheet in Unity on Ubuntu 16.04

To display the keyboard shortcuts, hold the "Super" key--most likely the Windows key, unless you have a Mac, in which case I don't know.


Try this. Open a terminal with Ctrl + Alt + t. Type the following:

sudo modprobe -r psmouse
sudo modprobe psmouse

This will remove the psmouse driver and add it back again.


You can transfer them using a script with "imapsync"
her a script I used for a migration to google mail. It can be used with any mail server imap ready:

SERVER1=imap.source.com
SERVER2=imap.dest.com

#Uncomment to hide folder sizes
FAST="--nofoldersizes"

#Uncomment to do a dry run (no actual changes)
#DRY="--dry"

#Uncomment to just sync folders (no messages)
#JUSTFOLDERS="--justfolders"

#Uncomment to just connect (no syncs at all)
#JUSTCONNECT="--justconnect"

#Set the path to your imapsync binary
imapsync=imapsync

#Users file
if [ -z "$1" ]
then
echo "No users text file given."
exit
fi

if [ ! -f "$1" ]
then
echo "Given users text file \"$1\" does not exist"
exit
fi

while IFS=';' read  u1 p1 u2 p2; do {

$imapsync --usecache --syncinternaldates --nosyncacls --tmpdir /var/tmp --host1 ${SERVER1} --user1 "$u1" --password1 "$p1" --host2 ${SERVER2} --port2 993 --user2 "$u2" --password2 "$p2" --ssl2 ${FAST} ${DRY} ${JUSTFOLDERS} ${JUSTCONNECT} --exclude "Sent|^Delet|Drafts|Spam|Calendar|Brouillons|^Calend|envoi|^Contacts|Flux|sirable|Flux RSS|^Historiqu|Infected|Journal|Junk|LinkedIn|Notes|Outbox|^Probl|supprim|Courrier ind&AOk-sirable" --regextrans2 "s,^&AMk-l&AOk-ments envoy&AOk-s$,[Gmail]/Messages envoy&AOk-s," --regextrans2 "s,^INBOX/,," --regextrans2 's{Sent Items$}{[Gmail]/Messages envoy&AOk-s}' --regextrans2 's{Sent Messages$}{[Gmail]/Messages envoy&AOk-s}' --regextrans2 's{&AMk-l&AOk-ments envoy&AOk-s$}{[Gmail]/Messages envoy&AOk-s}' --regextrans2 's{Éléments envoyés$}{[Gmail]/Messages envoy&AOk-s}'
}
done < $1

and the command line for launching the script is

./script.sh sample.txt

where sample.txt is a file containing adress and password of each user for both servers:

usersource@example.com;password1;userdest@example.com;password2


How to run a command when ext4 errors are detected?

You can solve this via systemd if you want to check every 15 minutes if your root filesystem is read-only or not:

Create the script that checks the filesystem and make it executable:

#!/bin/sh

unset $rootfs
unset $status
rootfs=SDXn #Replace with sda1 eg.

grep -E ''$rootfs'.*\ ro' /proc/mounts 2>&1 > /dev/null
status=$?

if [ $status = 0 ];
    then
        echo "$rootfs is not okay"
        killall nextcloud
        exit 1
    else
        echo "$rootfs is okay"
        exit 0
fi

Create the systemd service in /lib/systemd/system/:

[Unit]
Description=Kill nextcloud client when filesystem is read-only

[Service]
Type=oneshot
ExecStart=/path/to/script.sh

Create the systemd timer in /lib/systemd/system/ and enable/start with systemctl [enable|start] name_of_file.timer:

[Unit]
Description=Kill nextcloud client when filesystem is read-only

[Timer]
OnCalendar=*:0/15

[Install]
WantedBy=timers.target

Please note that the .timer and .service files need to have the same name.


Can I upgrade ath9k driver to ath10k in Xubuntu 18.04?

There is no way to "upgrade" ath9k to ath10k because these are two different drivers for different hardware.

Both modules are included in the 4.15 Linux kernel.


Adding firewall rule makes multiple entries

AFAIK, NTP works on UDP. So you can try something like,

sudo iptables -A OUTPUT -p udp --dport 123 --sport 1024:65535 -j ACCEPT
sudo iptables -A INPUT -p udp --sport 123 --dport 1024:65535 -j ACCEPT


OMG! Ubuntu! recently reviewed a tiny Linux laptop called the Ben NanoNote. Like the Pandora, this device doesn't run Ubuntu, but as Aamir mentioned, I doubt the traditional Ubuntu flavors would do well on a device this small.

Unlike the Pandora, this device actually is available for purchase online. The price is $99.


-o smtpd_recipient_restrictions=permit_mynetworks,reject

avoids this error.

It's still not recognizing my networks, but that's another issue.


Can we make active applications (that don't have assigned launcher icons already) near the Dash launcher/

The launcher gives you keyboard shortcuts to switch between windows. These are dynamic and based on the launcher position. If Nautilus is the first item, for instance, then you can start an instance or switch to an existing instance by pressing super+1. To display all open Nautilus windows, you'd then press super+11. (one one) In order to open a new instance, even if you already have one, you'd press super+shift+1.

Once you get used to them, these are extremely efficient keyboard shortcuts. However, if you placed new applications at the top, then the keyboard shortcuts would also be random, which would remove all the benefits. Another thing is that you may fill your launcher with more entries than it can display, in which case the lowest entries will be compacted or run out of the screen so you have to scroll. You probably wouldn't want your most frequently used applications to become less available.

Adding to the top would also create two different groups of entries; the locked ones (the most frequently used) and the others. If you then decided to lock an entry to the launcher, what should happen? Should it be moved to the bottom of the list? And if you unlock an entry, should it be moved to the top of the launcher, or to the bottom of the unlocked entries?

For these reasons – and I'm sure there are more – I think it's highly unlikely that your idea will be implemented in Unity.


How can I add drivers for the Aopen XC cube to ubuntu 12.04?

I did what this guy did for his SIS and created a conf.d folder with configuation files that match my monitor's resolution.

ubuntuforums.org/showthread.php?t=2060174


How to change account to write reviews for Ubuntu Software Center?

The only way I know is to delete the current password for the Software Center and then sign in again and select the "already have account" and sign in using the other account.
There may be a more elegant way to do this as this is a quick and dirty solution but here it is.

Open the dash and start typing "password" , the application "Passwords and Keys" will come up. When you open the application you will see the following.

If you click on the arrow the password list will open and you will be able to right click on the password for the Software Center.

On the right click menu you will be able to delete this password.  As I said above, you will then need to log in using the password to your other account and will have to repeat the process every time you want to switch between accounts.


All versions of skype for ubuntu are called "beta" so your version 5.0 is beta, too!

skype blog announcement


Firefox with nvidia-driver-396 driver has no 2D acceleration

I managed to fix this by setting the option layers.acceleration.force-enabled to true in Firefox. Apparently my driver is blocked by my platform, no idea why.


Why does nautilus use 90%+ cpu at startup?

Nautilus uses a lot of CPU when you log in as part of the process of loading your desktop and setting up a few things behind the scenes. So long as it returns to a normal level a little later, nothing is wrong with your system, and there is little you could do to change that happening.


How can I use a camcorder as webcam on USB mode?

Well I've been rummaging around and I can't find anything that suggests you can use the DCR-SX15 as a webcam through USB. If you can provide something to the contrary, I'll be quiet.

Why are you against analogue? You can pick up an AverMedia DVD EZMaker for ~£30 and it should show up as a V4L device out the box. You can pipe that through something like Webcam Studio and your computer will treat it like a real webcam. You might not even need that last step.


Invoke a wine installed application from command line

If you are using wine installed from the repositories then wine related files is stored in a folder called ~/.wine

Windows programs are stored within this folder - for example ~/.wine/drive_c/program_files/Internet Explorer

You can start a windows program in a similar way as from a command line in windows but prefix it with wine

for example

wine "c:\program files\internet explorer\iexplore.exe"

Thus if your divx called (for example) divxplayer.exe is installed - for example in ~/.wine/drive_c/program files/divx

then you can start your wine divx player

wine "c:\program files\divx\divxplayer.exe"


Did you install Ubuntu already?

If so, then you may have ability to remove Windows partitions and allocate their space for some Ubuntu partitions.

If not, then use Live CD and install Ubuntu on whole disk, or make partitions yourself.


The filename might have some strange characters which you cannot see in the terminal.
If this is the only file in the data directory I would remove the data directory and take the file with it,
rm -rf data

otherwise try using a gui file manager to remove it or see if you can remove it with a wildcard pattern, use ls with the pattern first so that you ensure you remove the target :)
ls LHRA*.gz

if that lists your file then
rm LHRA*.gz

If it was in use by another process the message would be different.


Create OpenSUSE bootable USB stick from Ubuntu?

@fossfreedom Note that I'm not trying to create a live USB stick. I
  just want to boot from the USB stick to install openSUSE. I read those
  instructions but it wasn't clear to me if they applied to the
  installation image as well as the live image. – becko 10 mins ago

Yes, those instructions do apply to installation USB creation. You will need to know the block device path of your USB stick.  Use lsblk to find that out. In this example I am using /dev/sdb but it could be anything else.

Ensure the usb stick is unmounted with

udisksctl unmount --block-device /dev/sdb

and burn the iso image to the USB

dd if=/path/to/downloaded.iso of=/dev/sdX bs=4M

For instance,

dd if=/home/xieerqi/Desktop/openSUSE-Leap-42.1-DVD-x86_64.iso of=/dev/sdb bs=4M

The command will take a long time to complete, so, be patient. You can use this

dd if=/home/xieerqi/Desktop/openSUSE-Leap-42.1-DVD-x86_64.iso of=/dev/sdb bs=4M  && zenity --info --text="DONE"

to show a notification when the burning is over.


How do I make the battery indicator always show my laptop battery by default instead of the mouse battery?

I remember this being fixed in one of the later releases. I'm on 15.04 right now and the battery always indicates the laptop battery, never the mouse.

You can try to upgrade to 15.10, however this might be a less stable release than 14.04. You can wait until the next lts: 16.04, (april 2016) to upgrade...


How detect modem connected to the USB of system through commands in linux

Look at the output of dmesg after connecting the USB device. Further you can use wvdial to dial your modem.


Neither GRUB Nor Windows Recognize Each Other

A very common mistake.
Sounds like you installed 1 OS with BIOS and the other in EFI mode. This is the typical result.
The best thing to do is to re make the live media to match the mode of the already installed Windows OS and re install Ubuntu.
If the install modes had matched the Ubuntu install would have seen the existing Windows OS and asked you if you wanted to install beside it.
Then you would have Grub that would let you choose OS on start up.


/mnt is an empty directory by default.

You can re-create it by running

sudo mkdir /mnt

But if you had something mounted there, that is not that easy. You probably removed everything from the mounted device.


Maas will commission machine, but won't let me turn it on

Off hand, I'd guess this is mostly an HP issue since the Dell stuff works fine.

I'd suggest first seeing if there are firmware updates for your hardware.  There tends to be quite a few bugs in HP's iLO IPMI implementations though usually their power interfaces seem reliable.

Second, logs are in

/var/log/maas

There's a lot of information in there for debugging.

Last, you can try some of this stuff manually.  Maas uses ipmi_chassis_config tool to boot machines.  You can try executing that directly from your machine. Docs are available in man pages or here:

http://linux.die.net/man/8/ipmi-chassis-config

See /etc/maas/templates/power/ for some of the options on this.  Also check the versions of the ipmi tools on your machine and look for bug reports on that.


Two monitors when only having one in 13.10

I am not an expert but I had the same problem. I have finally find the solution on this forum (here).

First, enter xrandr in your terminal. You will see that there are several outputs which are connected. The LVDS1 is your laptop's screen.
Normally, there is another outpout called VGA-1 orVGA-2 which is also connected. You have to note the name of this output.

Then, edit your grub with gksudo gedit /etc/default/grub and add video=VGA-1:d (VGA-1 is the name of the wrong output) in the GRUB_CMDLINE_LINUX line (you must have something like GRUB_CMDLINE_LINUX="video=VGA-1:d").

If your output is called like VGA-1-1, set video=VGA-1:d (setting video=VGA-1-1:d won't work).
If your output is called like VGA-1-2, set video=VGA-2:d (setting video=VGA-1-2:d or video=VGA-1:d does not seem to work, although one may still try them out separately to be certain).

Then update your grub with sudo update-grub and reboot.


premature end of file /boot/vmlinuz... error while booting dual boot Ubuntu

error: premature end of file /boot/vmzlinuz-4.2.0-25-generic.

That means that somehow the file containing the kernel was truncated somewhere in the middle. You'll need to reinstall the kernel package but you'll need to boot a different kernel for that since this one is broken.

I'll assume that you have a different kernel (older?) installed for Ubuntu.

When you boot your computer open the Grub menu and select the "Advanced options for Ubuntu" entry. In the appearing submenu select any entry that doesn't refer to kernel "4.2.0-25" and that isn't tagged with "recovery mode". The names may be localized to your language; just choose the corresponding translated entries.
Log in normally and open a terminal (Ctrl+Alt+T). Run the following commands:

sudo apt-get update
sudo apt-get install -f linux-generic
sudo apt-get install --reinstall linux-image-4.2.0-51-generic

Reboot and everything should be back to normal.

If you run into issues during with the apt-get commands please edit your question, select, copy and paste their output into your question and notify me in the comment section of this answer.

If you don't have a different kernel to boot, you'll have to use a Live DVD/USB which makes things somewhat more complicated. If that's the case, please leave a comment and I'll extend my answer accordingly.


My home partition slowly fills up until the system is unable to complete even simple tasks

I cleared the errors to the file as well but it just kept filling up.

To avoid a reboot, I killed the vino-server process:

$ ps -eaf |grep vino
  username  5849  5765  3 Jun21 ?        09:19:12 /usr/lib/vino/vino-server --sm-disable
  username 18207  5891  0 21:07 pts/1    00:00:00 grep --color=auto vino

$ sudo kill 5849

I cleared the errors again:

$ > /home/useraname/.xesession-errors

Then I restarted the process:

$ /usr/lib/vino/vino-server --sm-disable

FYI - this is ubuntu 12


I use Jupiter:

sudo add-apt-repository ppa:webupd8team/jupiter
sudo apt-get update
sudo apt-get install jupiter

After installing that, just open the application. Use Performance in the applicaton menu and set to Power saving and you should almost immediately hear the fan slowing (if your temperature sensors don't sense a high temperature).

It also allows you to disable some devices and set screen resolutions, monitor settings, etc.

Use lm-sensors to get an idea of the temperatures.

sudo apt-get install lm-sensors
sudo sensors-detect (say yes to all)
sudo sensors


Crazy boot and reboot times after upgrading to ubuntu 15.04 (a stop/start job is running for session c2)

I managed to fix this by rolling back from systemd to upstart. More info here:

https://wiki.ubuntu.com/SystemdForUpstartUsers

Permanent switch back to upstart
Install the upstart-sysv package, which will remove ubuntu-standard
and systemd-sysv (but should not remove anything else -- if it does, yell!),
and run sudo update-initramfs -u. After that, grub's "Advanced options"
menu will have a corresponding "Ubuntu, with Linux ... (systemd)"
entry where you can do an one-time boot with systemd.

If you want to switch back to systemd, install the systemd-sysv and ubuntu-standard packages.


Ugh. Somehow, I never realised that localhost wasn't immune to the firewall.

I added an iptables rule for the localhost interface, and now it works.

iptables -A INPUT -p tcp -m multiport --destination-ports 3350 -i lo -j ACCEPT

In the future I'll use this rule to make sure all localhost traffic is allowed:

iptables -A INPUT -p tcp -i lo -j ACCEPT


Use functions ! The advantage of this method is that you can add other optional positional parameters to function call when you run it.

term1(){
    xterm -hold -title "term1" "$@"
}

Place this into your ~/.bashrc file and run source ~/.bashrc.  Same idea for other commands.

In order to keep terminal "alive", you need to spawn shell at the end, i.e. do

term1 -e "cd place1; command 2;bash"

Terminal itself is just a window, and it doesn't have shell alone for you to interact with, so unless you spawn one - you won't get interactive shell.


Spam entries in mail log, but doesn't appear to be from a PHP script?

Most likely the malware ClamAV found is covering its tracks in some way.

You can see it's sending spam and you've isolated it to at least a Wordpress exploit, so disable the Wordpress installation(s) in question by re-naming the docroot directory. Then re-install WP manually to the latest version.

Always best to run a rootkit check after that if you can too.


Incorrect encoding in downloaded installer shell script

Why did you open the script in mousepad? AFAIK, mousepad is a text editor. To install the script do the following.

Step 1: Press Ctrl Alt t to open terminal

Step 2: Find the directory in which you have downloaded the installer(probably Downloads)

Step 3: Enter that directory using

cd Downloads

Step 4: Run the command. This command fill find the scripts present in the directory

ls -l | grep .sh

Step 6: Give the script executable permission using

chmod +x <filename>

replace  with the installer file name

Step 7: Finally run the script using

./<installer>

replace  with the installer file name


Ubuntu Process high memory usage (almost 99%)

I just found a user on the archlinux forum with a similar query/problem there are several possible solutions suggested there that you might try. here is the link https://bbs.archlinux.org/viewtopic.php?id=189975


VLC not playing aac files and a webm file

You should specify which version of Ubuntu you are using (Desktop [LXDE, XFCE, KDE, Mate, Unity], which processor type [32-bit, ia64, 64-bit and so on] and which edition you are using [12.04, 14.04, 16.04 or other]) to enable the answers you are presented to be more accurately directed at your needs.

If you have ubuntu restricted extras installed you should also have ffmpeg [and here is where the edition of Ubuntu is important because gstreamer0.10-ffmpeg does not exist for 16.04] installed as well as libavcodec54 libav-tools, ffmpeg, gstreamer0.10-ffmpeg, libavcodec-extra-53, libavcodec-extra-54 and/or others to ensure you have full coverage for (nearly) all audio and video file types you should follow and install the list of codecs and apps presented by Arch Linux (I am only linking to Arch Linux because I have not been able to discover a Ubuntu page which covers as much and Arch Linux covers things exceptionally well on the following page) - https://wiki.archlinux.org/index.php/codecs
But, if you are only concerned with AAC and have already installed Ubuntu-Restricted-Extras (as you stated you had) then I strongly suggest installing Clementine which does play AAC so long as the codec is installed (and for you it is because you made clear that you have already installed Ubuntu restricted extras).  So, sudo apt-get install clementine and you will be able to play AAC files using that application.

Apart from installing clementine if you must use VLC then you need to install a few more packages. sudo apt-get install libavcodec-extra libavcodec-ffmpeg-extra56 libavcodec-ffmpeg56 libavutil-ffmpeg54
Once installed, open VLC and in the settings make the following changes:
Open VLC.  Click "Tools" then click "Preferences"  In preferences select "All" in Show Settings at the bottom of the window. Find "Input / Codecs" then "Video Codecs".  Now click "FFmpeg" and scroll down (on the right) until you see "Strict Standard Compliance" and change it to -2, then "Specify AAC Audio Profile" to use hev2 (just type it in after removing what was there).  Save it and your VLC will play AAC files.

As for webm files I do not have as much nor am able to find one so I cannot provide a useful answer (except to say that VideoLaAN, the company which makes VLC states that webm files are covered after VLC version 1.1.0, but that was released years ago). I will continue to look for a webm file and try to provide you a manner to enable as much in your VLC.


Disable network configuration services during boot time

A better ideea than disabling the service is to remove the sleep time. To do this, open /etc/init/failsafe.conf with your favourite editor, and around line 25 you should see the following lines of code:

# Plymouth errors should not stop the script because we *must* reach
# the end of this script to avoid letting the system spin forever
# waiting on it to start.
$PLYMOUTH message –text=”Waiting for network configuration…” || :
sleep 40
$PLYMOUTH message –text=”Waiting up to 60 more seconds for network configuration…” || :
sleep 59
$PLYMOUTH message –text=”Booting system without full network configuration…” || :

To solve your problem, just comment the sleep times (add '#' in front of the text). It should look like this:

# Plymouth errors should not stop the script because we *must* reach
# the end of this script to avoid letting the system spin forever
# waiting on it to start.
$PLYMOUTH message –text=”Waiting for network configuration…” || :
#sleep 40
$PLYMOUTH message –text=”Waiting up to 60 more seconds for network configuration…” || :
#sleep 59
$PLYMOUTH message –text=”Booting system without full network configuration…” || :


System freezes completely with Intel Bay Trail

Your processor is affected by the c-state bug
This causes total freezes when the CPU tries to enter an unsupported sleep state. It's a problem for many Bay Trail devices especially with newer (4.*) kernels.
Affected processors AFAIK:
Atom Z3735F (Asus X205TA, Acer Aspire Switch 10, Lenovo MIIX 3 1030)
Atom Z3735G
Celeron J1900 (Asus ET2325IUK, shuttle XS35V4)
Celeron N2940 (Acer Aspire ES1-711, Chromebook)
Celeron N2840 (Acer Aspire ES1-311)
Celeron N2930 (Jetway JBC311U93, Zotac Nano CI320)
Pentium N3520
Pentium N3530 (Acer V3-111P)
Pentium N3540 (Dell Inspiron 15 3000, Lenovo G50, ASUS X550MJ)

(please (suggest an) edit to add your own device if affected)
Complete list of Bay Trail processors may be found here
There is a simple workaround for this until it gets properly fixed upstream.
You just need to pass a kernel boot parameter and the random freezing stops completely. The parameter may increase battery consumption slightly, but it will give you a usable system.
You do this by editing the configuration file for GRUB:
Boot Ubuntu and open a terminal by pressing Ctrl+Alt+T then type
sudo nano /etc/default/grub

Find the line that starts GRUB_CMDLINE_LINUX_DEFAULT=
This needs to be changed to include intel_idle.max_cstate=1
So after your edit it reads something like
GRUB_CMDLINE_LINUX_DEFAULT="quiet splash intel_idle.max_cstate=1"

quiet and splash are default parameters for Ubuntu Desktop - no need to change them, or any other pre-existing parameters
Now save the file by pressing ctrl+o then enter and exit by pressing ctrl+x
Now run
sudo update-grub

Then reboot.

What to do if you don't have enough time to do this before the system hangs
No problem. As explained on the help page I linked to earlier, you can add the parameter to GRUB before booting. Note that this only passes the parameter for the current boot, so you still have to edit /etc/default/grub once you have booted to make the change permanent.
You need to get to the GRUB menu. If you are dual booting this will appear anyway, if not you have to press and hold (or tap) shift after pressing the power button to turn on.
When you get to this screen select Advanced Options for Ubuntu. You can move the cursor to a different kernel, or leave it in place to edit options for the default. Instead of pressing enter, press e and you will go into edit mode, looking vaguely like this.
Move the cursor down to where it says quiet splash, put a space after splash and carefully type intel_idle.max_cstate=1 making sure there is a space after it as well.
Now press F10 or Ctrl+x to boot.


Check the USB Driver version. In case your USB device 2.0 --> Port 3.0 means its supported 2.0 Speed, Its depends upon your motherboard specification / USB port manufacturer. So its will depend upon your motherboard.

  Don't mention I3 it is the Processor of your system,

  So check the motherboard. In-case 3.0 below > > older version means update the motherboard hardware.


Brother DCP-L2560DW will it work on ubuntu

Just installed using this driver: http://support.brother.com/g/b/downloadlist.aspx?c=gb&lang=en&prod=dcpl2560dw_eu&os=128
Printing and scanning seem to work fine.


If you want to dual boot, you should install Windows first. The Linux Grub2 bootloader can handle a pre-existing Windows installation, but the last time I tried it, the Windows installer will wipe out your Linux boot. It is not worth the trouble.


How to install on a mac and get rid of OSX

you'll need rEFIt to be able to do the dual boot.


Logical sector size for physical sector size of 4096

There is a difference between block size and cluster-size but there is no such thing as logical sector size in ext4.

Probably you already have an IO block of 4096: try doing a stat .bash_logout in your home directory.

  File: ‘.bash_logout’
  Size: 220         Blocks: 8          IO Block: 4096   regular file

For more info: man mkfs.ext4

And finally: Stop worrying! ext4 uses heuristics to format your drive as efficiently as possible.  ;-)


Did you install xserver-xorg-input-synaptics
?

sudo apt-get install xserver-xorg-input-synaptics


$ echo 'Parametersettings:' | sed 's/Parametersettings:/#!\/bin\/bash/g'
#!/bin/bash

or use a different delimiter, avoiding the need to escape the / characters:

$ echo 'Parametersettings:' | sed 's%Parametersettings:%#!/bin/bash%g'
#!/bin/bash


1) pip3 install matplotlib error then 2) pip cannot import main

You need to Use python3 -m pip install instead of pip install

sudo python3 -m pip uninstall pip && sudo apt install python3-pip
--reinstall


You can use gparted for this. Also installable by sudo apt-get update && sudo apt-get install gparted

To make one big fresh partition (deletes all data on your filesystem):

First you'll have to make sure that both the partitions - unallocated
space and the other partition to merge are either both logical
partitions or both primary partitions. One logical and one primary
will not work.
After checking and confirming the first step, delete the partition holding a filesystem.
Third, the unallocated space is now bigger since you have deleted a partition.
Create a partition of required size.

To increase the size of the partition holding data: (Although this is mostly safe, it's always wise to make a backup of your data!)

First you'll have to make sure that both the partitions - unallocated
space and the other partition to merge are either both logical
partitions or both primary partitions. One logical and one primary
will not work.
Second, right-click on the partition in question and click resize. Fill in the size as required.
Click resize/move and then click Apply all operations


How to get the sendto mail recipient in Xubuntu 14.04 to use Geary email client?

Geary doesn't currently support this feature.  You can file a ticket requesting it on GNOME's Bugzilla.


-e check the file /usr/bin/ibus-daemon exists or not? exist means true does not exist means false.

! wants to confirm above value is false if above value is true, it will not execute anything.

[ "x$XDG_SESSION_TYPE" = "xwayland" ] this can have either one of below values based on how you choose to login at the login screen. which session you will choose x11 or wayland.

"xx11" = "xwayland"
"xwayland" = "xwayland"

example output of $XDG_SESSION_TYPE

administrator@pratap:~$ echo $XDG_SESSION_TYPE
x11

another example:

administrator@pratap:~$ echo $XDG_SESSION_TYPE
wayland
administrator@pratap:~$

if the first expression is false and x$XDG_SESSION_TYPE = xwayland
then exec the command env IM_CONFIG_CHECK_ENV=1 im-launch true

if the first expression is true or x$XDG_SESSION_TYPE is not equal to xwayland then don't do anything.

see man test

! EXPRESSION
              EXPRESSION is false

and

   -e FILE
          FILE exists

you can read more about what this command does then exec env IM_CONFIG_CHECK_ENV=1 im-launch true;

see man env & man im-launch

By default in Ubuntu 19.10 /usr/bin/ibus-daemon exists. so the command will not be executed.

env IM_CONFIG_CHECK_ENV=1 im-launch true

when there is the file /usr/bin/ibus-daemon and my session is x11

here is something about IM

when there is no file /usr/bin/ibus-daemon and my session is wayland

here is the thing which is different from above, which means the env is applied and then a chain reaction followed.

so, if you disable or enable this from startup list nothing happens unless no existence of this file /usr/bin/ibus-daemon and your session is wayland conditions are met.


Nautilus file names are not visible after LibreOffice invocation

The update procedure at this link solved the problem for me.

The procedure:

sudo add-apt-repository ppa:ubuntu-x-swat/x-updates

sudo apt-get update

sudo apt-get install nvidia-current


Enabling Load Balancer as a Service (LBaaS) on Autopilot deployed OpenStack

This answer describes how to access the inner juju environment:

Add node to existing landscape openstack

Ideally you should find a juju way to enable LBaaS, because that's how the cloud was deployed by the Autopilot.


Ubuntu 16.04 hangs on shutdown/restart (Dell XPS 15 9560)

Eventually, the solution that fixed everything for me was the following (at least for my system configuration):

edit /etc/default/grub

add acpi_rev_override=1 to your GRUB_CMDLINE_LINUX_DEFAULT parameters
(in my case the line looks like this):
   GRUB_CMDLINE_LINUX_DEFAULT="quiet splash acpi_rev_override=1"

run sudo update-grub from the terminal

after shutting down your machine one more time from the power button, the problem should have been fixed.


How to reverse a video and fast forward it using Kdenlive

I’ve just run into this and it seems like a bug. When you apply the speed effect the ‘reversed’ clip shrinks to a tiny size on the timeline and you can only delete effects and the clip from the timeline (if you can find it).

You can easily reverse clips, but I think the reversal is actually just another saved job, so what you can do with that ‘reversed’ clip is severely limited. E.g. the clip I’m dealing with is 195 MB, but the .mlt reversed version shows as 3.4 KB.

The solution is to render an actual reversed version of the clip.

Kdenlive

Either….

save your project with a new name and clear the timeline (easy way to keep same project settings)
add a new track and disable all the others (tedious!)
create a new project with the same settings, add the source clip & ‘reverse’ it

…then…

drag your ‘reversed’ clip to a (new) track
render it

ffmpeg

ffmpeg -i source-clip -vf reverse -af reverse reversed-clip

or, to only reverse the video…

ffmpeg -i source-clip -vf reverse reversed-clip

Note that this may not practical for large clips as I’ve read elsewhere that the entire file is buffered, so it is very memory-dependant.

Although this was a lot quicker, for me it also seemed to reduce the quality of the reversed clip, which was unexpected.

  Source: 9,880 kb/s, AVC (Baseline@L3.1)(1 Ref Frames) 195.4 MB
  Reversed: 371 kb/s, AVC (High@L3)(CABAC / 4 Ref Frames) 8.2 MB


This is what man pages are for

ls:

http://manpages.ubuntu.com/manpages/raring/man1/ls.1.html

  -r, --reverse
                reverse order while sorting

  -R, --recursive
                list subdirectories recursively

rm:

http://manpages.ubuntu.com/manpages/raring/man1/rm.1.html

  -r, -R, --recursive
                remove directories and their contents recursively

So with the command rm, -r and -R are the same, but not so with ls


How to restore scroll wheel functionality in AbiWord?

You are likely suffering from bug 991399 where we can read that the Abiword version 2.9.2 packed with 12.04 is a development version that should not have made it into the release.

Mouse scrolling is still possible when the mouse cursor is positioned on the scrollbar on the right side window. If that is not a workaround for you you may need to downgrade Abiword to the last stable version abiword-2.8.6.


Network - Ubuntu Server 16.04 cant connect using ethernet

Considering enp2s0 is your network interface try these:

sudo ip link set dev enp2s0 down
sudo dhclient enp2s0


Ubuntu 16.04 alongside Windows - shrinking D partition instead of C

Shrinking D is okay too
As long as D is not a separate physical drive, it does not matter if you shrink C or D. Even if D in a different physical drive, you can Install Ubuntu there as well. The process would be slightly different as you will have to use the advanced installation method call Something Else to select the second drive and manually setup the system partition for Ubuntu.
As long as C and D are two partitions in a single physical drive, and you shrink D to make space for Ubuntu system partition, the standard installation process should find that empty space and offer to install Ubuntu there.
Hope this helps


Changing multiple directory permissions at once

Try chmod g+r /home -R

That should change the permissions for every file under /home to have read access for group. The -R option runs the command recursively


Will Unity 7.3.1 be backported to 14.04?

No, Unity 7.3.1 will not be backported to 14.04.

The good news is that, with the exception of changes made to build or run with newer versions of software in Ubuntu 14.10 (for example, compiling under GCC 4.9 instead of GCC 4.8, newer GTK+ libraries, etc.), almost all bugfixes have been backported to Unity 7.2 and SRU'd into 14.04.  There are no bugfixes for high-DPI that appear in 14.10 that have not been (or are not being) backported to 14.04.  We expect that to continue in the Vivid cycle.

The SRU process is a little slow:  fixed need to land in the current Ubuntu development version first and be tested, then a careful process of verification and validation must be followed before the change appears in 14.04.


Connection to the internet keeps dropping on Acer netbook

If Ubuntu didn't detect it it's probably not supported, I had an unsupported ralink card in my laptop that i had to replace with an intel wifi link minipcie card, Now wireless works fine for me.

This is the card i bought Here


Migrating from Windows 7 to Ubuntu 14.1 64 bit

Some advice for doing windows stuff on ubuntu: try installing wine, it does the job. download here or you can search for it on the ubuntu software center.


Using cp -av command showing destination folder as not a directory. Please help in solving it

You are missing the leading /, try:

sudo cp -av libcufft.so.7.5.18 libmwservices.so /usr/local/MATLAB/R2016a/bin/


use this link https://help.ubuntu.com/community/UpgradeNotes?_ga=1.236620673.1065164992.1468443213. This link can tell everything about upgrade process of ubuntu.


Xubuntu 13.10: Only four levels of brightness?

Different video drivers. Once you have determined what driver is used by Mint Mate, use that driver with Xubuntu.


How to find out the command to add program to session startup programs?

To find out the command for any program you should type this in the terminal-

whereis *application name*

For example,
If you want to find out the command to run Gedit the type in the terminal-

whereis gedit
and you will get an output like this-
gedit: /usr/bin/gedit /usr/lib/gedit /usr/bin/X11/gedit /usr/share/gedit /usr/share/man/man1/gedit.1.gz

out of that,the very first path you see-/usr/bin/gedit is the path to the executable file...Which should be added in the startup applications list.. :)
Hope it helps