Can't log in to Ubuntu 12.04 "checking battery" flashes up then goes back to login screen

Try these solutions:

From your tty remove the .Xauthority file and also need to remove the .xsession-errors files.

sudo rm .Xauthority
sudo rm .xsession-errors*

Check the home directory:

ls -l /home

you may have to give ownership back to your account using chown

sudo chown -R username:group /home/username


Where to report bug for ubuntu-desktop-next?

Searching on packages.ubuntu.com: common mistakes
There is a ubuntu-desktop-next package. There are 2 possible reasons that could explained why you didn't find it:

You might just mispelling while searching for it. Only interchanging two characters will suffice to not find the correct package. For example, as you mentioned in your question: ubunut-desktop-next

You search it with the wrong version number. By default, the search is looking for packages in  the last current LTS version (trusty 14.04). Since the package is only available since utopic (14.10+), it didn't find it. But the search still warns you that it has found a package with this name but it can't currently be displayed:

Some results have not been displayed due to the search parameters.

Then the bug reports link is just taking you to the related project on Launchpad: ubuntu-touch-meta.
Before reporting a bug
Since you've found a bug 2 weeks ago, don't forget to check:

if someone didn't already file it
if the new builds didn't already fixed it


Just as Fabby said, you have to stop the array before making any changes. I did not have that in mind, thank you Fabby.

Here is the solution step by step:

# mdadm -S /dev/md0

# mdadm /dev/md0 -r /dev/sda

# dd if=/dev/zero of=/dev/sda bs=1M count=1024

after changes

# rm /etc/mdadm/mdadm.conf


"apt-get --with-new-pkgs upgrade" not being enough to solve kept back packages problem

The answer to your question is buried in the comments of the posting you linked to:  Sometimes a package is upgraded or changed and this package cannot coexist on the system with a prior version, or with some other package on your computer. " Think of llvm3.6 vs. llvm3.6v5 (with the "v5" meaning that it was compiled with gcc 5). These two cannot co-exist, only either of both can be kept on the system."

As I'm a relative novice, I cannot talk to the veracity of this particular situation but I can state that I used to use dist-upgrade quite often, and never entered a situation which broke my system.  I also run the most current released version of Ubuntu, and occasionally need to reinstall my system anyhow.

The current flavor of upgrades prefers the apt command set as opposed to apt-get.  There is some information at What is the difference between apt and apt-get?


I'd personally side-step all the lightdm and Xsession stuff and just launch my own instance of X that just started Firefox. Sounds nightmarish but it's really  simple with a little Upstart script

start on (filesystem and stopped udevtrigger)
stop on runlevel [06]

console output
emits starting-x

respawn

exec sudo -u thomas startx /etc/X11/Xsession /path/to/kiosk.sh --

Obviously change the username to whatever user you want to run this as, but that's pretty much it. Save that as /etc/init/x.conf and then you should be able to sudo start x and you're away (it'll  load at boot). If Firefox crashes, it'll reload X with a new instance.

If you've got a full-blown Ubuntu install sitting there, you might have to disable LightDM first with:

sudo stop lightdm
echo manual | sudo tee /etc/init/lightdm.override

And your Firefox profile is completely up to you. You might even want to script in some profile-restoration so that if somebody does break your profile, you just need to restart your x service and it'll be using the clean copy again. Just an idea.

I've since written a blog post on creating a Kiosk from scratch with 14.04 and Chrome.

For your wireless configuration problem, I'd suggest keeping as much of this away from casual users. You could set up a connection using a TTY fairly simply:

sudo nmcli dev wifi con <SSID> password <password>

That should add the connection to the system and connect (and auto-connect in the future) but I haven't tested it. It might not even need the sudo but that all depends on what privileges your main user has.

The simple benefit over loading something else in the background here is that there's no chance some passer-by is going to have access to a graphical network settings dialogue. It does require the operator to be able to follow instructions.

If they can't handle that, you could fairly easily modify your kiosk.sh to look for existing connections and ask some zenity-questions that feed into the previous nmcli command:

if [[ $(nmcli con | wc -l) == 1 ]]; then
    SSID=$(zenity ...)
    PASS=$(zenity ...)
    nmcli dev wifi con $SSID password $PASS
fi

That's just a rough idea. You'll need to work on that. There may be a better standalone graphical network-manager configuration application.


Accidentally deleted .bashrc on USB stick Ubuntu 12.04

As far as I know, deleting .bashrc would not do that to your installation, it looks quite irrelevant; from this answer on superuser,

  When an interactive shell that is not
  a login shell is started, bash reads
  and executes commands from ~/.bashrc,
  if that file exists. This may be
  inhibited by using the --norc option.
  The --rcfile file option will force
  bash to read and execute commands from
  file instead of ~/.bashrc.

so unless you are somehow opening a terminal on startup, you don't have to worry about your .bashrc, look for other problems with your installation.


How to increase downloading speed in ubuntu 20.04?

You can use XDM Download Manager for Ubuntu. It downloads 5-6 times faster than conventional downloaders. It's opensource and free. It also has firefox addon and Chrome extension, which grabs dowload links from popular websites.


Xperia Z network item stuck in Network Manager applet

First, try "Edit connections..." from the Network Manager applet. If the connection does not show up in the list, or cannot be removed from the list, find the corresponding file in /etc/Network Manager/system-connections and remove it.


Can Twitter monitor my browsing activities when using a client like Hotot or Gwibber?

Nope. Twitter does not track anything while you are using a Twitter client. The client does not transmit any private browsing data to Twitter, it only sends and receives tweets, replies and PMs.


Booting ubuntu desktop into command prompt

You can edit the kernel parameters in grub to add text as a boot parameter.

To do that temporarily (just for the current boot), you can edit the boot menu entry by pressing e (if you don't want the default boot menu entry, first select the one you want).  If you don't see the boot menu, you can hold down the Shift key during boot to make sure it gets shown.  You have to add the word text at the end of the line that starts with linux.

To make this permanent, you can add text to the value of GRUB_CMDLINE_LINUX_DEFAULT in /etc/default/grub.  If you didn't change that file before (some people remove the quiet and/or splash, or add other kernel options), the line will then look like:

GRUB_CMDLINE_LINUX_DEFAULT="quiet splash text"

After changing this, you should run sudo update-grub to regenerate the actual grub boot menu configuration.

When you want to start the GUI from the console, do it with:

sudo start gdm

To stop the GUI again, log out (to make sure all your settings are stored etc.), switch to the console, and do the same with "stop" instead of "start":

sudo stop gdm


Android Emulator Warnings (QStandardPaths, GLES1, FramebufferData)

I had the same problem. I did what the log says. So I created a folder with the name snap.android-studio in /run/user/1000/ with the permission 0700 (it was the default setting). The warning vanished.

I hope it is a useful answer for you.


Why do I get more free space than ext4 after formatting in XFS?

EXT3/EXT4 filesystems take 5% of partition size for security etc. (e.g. in "non free disk space disk" cause).

If it isn't root partition, You could change this 5% to e.g. 1% by doing:

sudo tune2fs -m 1 /dev/sda3

where you should change sda3 to your partition.


With Radeon graphics, black screen can be caused by video driver incompatibilities.  Fortunately there are alternative choices for drivers.  If you have the open source driver installed, you can try the proprietary driver (called fglrx).  If you have the proprietary driver installed, you can sometimes try a newer or older version.  If you're really stumped, then identify your radeon model number and do some googling to see which specific drivers and driver versions to use.

This link is a bit dated for 19.10 but the information may get you on the right path:

https://help.ubuntu.com/community/BinaryDriverHowto/AMD


Is it possibly to install Ubuntu without making partitions?

You can install.

As you said you have second hard-disk which you want to use only for Ubuntu. while coming to partition step choose manual.

Then choose your 2nd Harddisk which is usually /dev/sdb then make it as root partition with mount point /  thats it.

Now Ubuntu will install in that total harddisk(2nd one) and total space will be for Ubuntu only.

@OP : Recommended partition scheme


How can I edit a LibreOffice Writer template file (.ott) directly?

Like most LibreOffice file formats, the .ott file is just a compressed archive. Rename it to filename.zip and open it with the archive manager. You will find several files and folders in it. Most likely you want to edit the contents.xml file. When you're done, compress the files and rename the file to newfilename.ott. Unless you have made a mistake somewhere, you can open this file with LibreOffice. LibreOffice is not very lenient towards errors in the XML markup, and will refuse to open the file if you forget to close a tag, for instance.


Is there an equivalent to Adobe Creative Suite?

As far as I know, there isn't such thing as a "Creative Suite". What you have instead are several alternatives to the different programs in Adobe's suite:

Gimp vs Photoshop
Inkscape vs Illustrator
Scribus vs InDesign
Tons of editors and IDE's (such as Netbeans, Eclipse or Bluefish; or Kompozer, which is a WYSIWYG HTML editor, or Bluegriffon which is its rewritten although harder to use version) instead of DreamWeaver
etc

Those programs might fulfill your needs individually. The thing that they miss, though, is the great integration between Adobe's suite products (same icons, same GUI, easy to share things between them and so on).


~/.zprofile is not read on graphical login when user’s default shell is zsh

So apparently when zsh is run on login ...

You're running zsh in GNOME Terminal, not on login. Compare by switching to a TTY (CtrlAltF1), and logging in.

  it does not know it's a login shell

The term "login shell" is overloaded:

It's the shell mentioned in your passwd entry. Console-based login methods usually start this shell (try the TTYs, or sudo -l, or su -). "Login shell" with this context is used in discussion of user accounts.
A shell can be run as a login shell, irrespective of whether it is a login shell(1) of the user. With most Bourne-like shells, that's obtained by either using -l when run manually, or by using - as the first character of argument 0 when launched indirectly (by login, sudo, su, etc.). This meaning is used while discussing invocation of shells.

So, it isn't a login shell(2), because we are discussing how it is started (invocation).

.zprofile is read by login shells (2). GNOME Terminal does not run a login shell (2) by default. You have to tell it do so:

  Go to Edit -> Profile Preferences.
  Select the Title and Command tab.
  Notice how the Run command as login shell checkbox is unchecked! Check it.


executing certain commands do absolutely nothing

Run

which node

and in my case it displayed /usr/sbin/node.
If it says command not found, skip to 3. Remove it by

sudo rm /usr/sbin/node

Run

which nodejs

in my case it displayed /usr/bin/nodejs.
Make a link

sudo ln -s /usr/bin/nodejs /usr/bin/node

OR

sudo ln -s /usr/bin/nodejs /usr/sbin/node


Desktop flickers on Ubuntu 18.04 after Wake up from Suspend

Try this, it's worked for me (Lenovo G50-80 i3 Intel graphics):

Edit the file /etc/default/grub:
$ sudo nano /etc/default/grub

Add nouveau.modeset=0 to the line:
GRUB_CMDLINE_LINUX=""

i.e. change to:
GRUB_CMDLINE_LINUX="nouveau.modeset=0"

Save and close the file.

Update GRUB:
$ sudo update-grub

Reboot.


The Shell Theme option in GNOME Tweak Tool needs the User Shell Themes extension, as the mouse-over pop-up says:

The extension is available at https://extensions.gnome.org/extension/19/user-themes/, or by installing gnome-shell-extensions:

sudo apt-get install gnome-shell-extensions

If you installed it manually, instead of using the GNOME Shell plugin
(which works on Firefox), then you might need to restart GNOME Shell (press AltF2, type r, press Enter).


We had a pretty active discussion a while back when we implemented the
udisks2 interface in snapd. The outcome was that we don't want to give
arbitrary snaps access to block devices and added all access for those
directly into the udisks2 interface.

udisks2 offers a mediated way for all other snaps to deal with block
devices and generally also allows working with RAIDs. I say generally,
because this is a feature we haven't verified yet that it is working with the udisks2 snap currently in the store.

If support for RAIDs in udisks2 works users should be able to mount a
RAID on a directory in /media via a dbus API call.

One downside is that the udisks2 interface explicitly denies plug
connections as it still gives kind of privileged access to the system.
Every mount done via udisks2 will appear below /media and every snap
using the removable-media interface will get access to devices mounted
there, regardless if it's the system partition or not. So even the plug
side is a very privileged thing. That said, snaps can ask for a
snap-declaration on the store side to get connections to udisks2.

Another feature we support with the udisks2 snap is auto-mounting (documentation for this will be soon on https://docs.ubuntu.com/). This
allows a device to say that it wants removable devices like USB storage
device to be automatically mounted in /media as you know it from
consumer oriented devices like the Ubuntu Desktop. Depending on how the
RAID is setup this might be able to get the the RAID mounted on boot
into /media. Requirements for the automounter to consider a device are currently:

Device is not a system device (meaning it's not a partition on the
device we're booting the system from).
Device is not already mounted.
Device is a removable device (USB, CD/DVD).

Automounting can be enabled via:

$ snap set udisks2 automount.enable=true

when the udisks2 snap is installed.

For a very simple, unconfined solution you could just install the
udisks2 snap (given that it detects and works well with RAID devices)
and create a systemd unit in /etc/systemd/system/mount-my-raid.service

[Unit]
Description=Mount my RAID

[Service]
Exec=/snap/bin/udisks2.udisksctl mount -b /path/to/block/device

[Install]
WantedBy=multi-user.target

Then activate it via:

$ sudo systemctl enable mount-my-raid.service

and the RAID should be automatically mounted below /media on the next
system reboot.


How to download a package with dependency manually?

You can manually find the packages by searching packages.ubuntu.com.  For instance you can follow the links to get to a downloadable deb of one of the dependecies from here: https://packages.ubuntu.com/en/xenial/cpp-4.9-aarch64-linux-gnu.

There might be an easier way though.  Since this appears to be from Xenial, if you turn off all repos in /etc/apt/sources.list and only have the main and universe repos enabled for Xenial (eg. deb http://us.archive.ubuntu.com/ubuntu/ xenial main universe), then perhaps apt-get install gcc-4.9-aarch64-linux-gnu will work.  Make sure to do apt remove gcc-4.9-aarch64-linux-gnu first.  Also, be careful, make sure that only the dependencies you want are getting pulled in.  Sometimes this kind of thing can end up trying to install the Xenial glibc, which could break your system.


Printer "ripping" forever (network printer)

So I finally found the trick... Just replaced my Footmatic/pxlcolor driver by the equivalent Footmatic/Postscript.. I thought about it, although I have no idea who are those "pxlcolor" and "postscript" guys, because the other printer of my network is using a postscript driver and working perfectly well.

Wait, I just send a final test: Printing my whole thesis! or let's say 20 pages of it (I don't want to use all the paper of my company for a test :p)... Annnnd WORKING!!!! 3 months that I'm waiting for being able to do this halleluiah!


Launch a GNOME session in a Ubuntu machine I'm SSH'd into?

Another method is to use a local browser and use SSH as a proxy

ssh -D 3128 user@hostname

And temporary configure your browser to use localhost:3128 as a socks v5 proxy.

Since only the data and not the full rendering needs to go through the line this will also be much quicker.

If you need to do this more often, look for the foxyproxy extension that allows automatic switching based on rules.


New Ubuntu User Here, How Do You Get Wifi To Work

This will get you going however it would be much easier if you can connect to the internet using you phone or a USB dongle.
b43 driver (Open-source) is the one you want


Failed installing Ubuntu alongside Windows 8.1

It seems to me you have too many recovery partitions! But it might be the way your system was set up by your OEM, so who knows. You should not delete and merge recovery partitions into your C: partition unless you're sure you don'tneed them. From your screenshot, partitions 15.83 GB, 7.45 GB and 191.48 GB were probably created by Ubuntu and are safe to delete/merge.

To check which partitions were created by Ubuntu, I would use the Ubuntu USB to boot into the "Try Ubuntu without installing" option and use GParted (the file system on those partitions would probably be ext2 etc. or linuxswap, which I'm guessing is not detected by Disk Management in Windows).

You can then delete the partitions you want and merge the unallocated space into the existing NTFS (C:) partition, but it's probably safer to do that through Windows rather than GParted. I found this article that has details on how to do that.

Again, you should probably stay away from the recovery partitions unless you know what you're doing. The same goes for the EFI partition, which is probably used by Windows and would make it unbootable if deleted.

As always, if you're editing partitions with valuable data, you should make backups first.


Using Adobe Digital Editions to transfer books to the Nook, or a workaround

As soon as ADE downloaded the ebook, it added the encryption keys to it.
With that, Calibre can decrypt the epub file and transfer it to your nook.


How to build this Rust program in Launchpad? It fails to build

As pointed out in a comment in OMG!Ubuntu!, the source package of the Pop!OS PPA is much larger than the code in GitHub.
Most likely the devs are packing all the dependencies inside the source using cargo before uploading the source to Launchpad.

If you look near the end of the buildlog you can see the build server trying to unpack a missing vendor.tar and failing. That file contains all the dependencies needed to compile the big fat popsicle binary (that's why I'm not a huge fan of Rust software), which cannot be fetched online by cargo since Debian/Ubuntu has a proper build system that doesn't allow network access.
If you compare your build with the one from Pop, your compressed source
is 269.3 KiB, while the one from Pop is 12.4 MiB: the difference in size
is exactly the missing file.


Will the netinstall (minimal) work with a USB cellular modem?

Sorry, the minimal image includes only wired drivers and limited wireless (WiFi) support. What you want is not possible with the default mini.iso, although you can of course remaster it to include the necessary modules. Use the expert install, so you can drop to a shell (busybox) before the network detection part and load the modules, set the IP, etc.


"cannot determine current directory" while building haskell

I was able to solve this by just installing the right packages (no linking).

sudo apt-get install libgmp3c2 freeglut3 freeglut3-dev -y

I'll note that I already had these dependencies installed:

make libssl-dev build-essential curl git-core


End kernel panic - error while trying to boot

Go to http://www.memtest.org or https://www.memtest86.com/ (use the second link to get the latest free version), and download/run memtest to test your memory. Get at least one complete pass of all the tests to confirm good memory.


How to restart Ubuntu 12.04 using Autokey

If you're open to an easier suggestion not using AutoKey, you can go to System -> Preferences -> Keyboard Shortcuts.

From there click "Add".

Now name it "Shutdown" or something, and use "gksu shutdown -r 0" as the command.

Now click the "Shortcut" cell for its row, and press you're desired key combination.

NOTE: I am running Ubuntu 11.04 but this should be applicable.


Is it possible to boot ubuntu in uefi shell to fix bios boot options?

you can directly boot into the UEFI shell "also" with Serva.

http://vercot.com/~serva/an/NonWindowsPXE3.html

5.9 UEFI Shell

Note: Please consider not all the Shell.efi available out there will be compatible with your UEFI firmware version.


Crashing system - how to xhci_hcd unload and only allow ehci_hcd in Ubuntu 12.04, 13.04 for debug some usb hardwares

xhci_hcd is built into the kernel in at least 14.04.  You can recompile the kernel so it is a module instead (it's under Device Drivers | USB support in the kernel config menu, press spacebar until it is M, or set CONFIG_USB_XHCI_HCD=m in the .config file).  With that built you can then blacklist it and load and unload with modprobe and rmmod at will.

Unfortunately for me I think that my motherboard requires xhci_hcd even for usb 2.0 and cannot use just ehci_hcd, so not having the xhci_hcd module loaded means no usb at all (or I need to take further steps to get it working):

$ lsusb
unable to initialize libusb: -99

But it's useful to have a xhci module, I can at least recompile it with some hacks without having to recompile the whole kernel.


How to Run files and open folders as an administrater 11.10

Much easer to open terminal and type in

gksu nautilus

this will open up root nautilus, letting you move, copy, and edit protected files.


Try this:

Run Ubuntu Software Center
Install CompizConfig Settings Manager
Run CompizConfig Settings Manager (ccsm)
Click OpenGL
Ensure Vertex Buffer Object is unchecked


How to record stereo sound from Line-In in command line?

if you wanted to record from Line in ALSA, maybe you would hear sound if you select Line as capture device and increase capture level from 0

you could use arecord command for recording from ALSA

arecord -f [format] -D hw:card,device -d [duration]


Deleting recovery partition on dual boot machine and resizing window 7 partition

I removed the Recovery Partition from my Dual Boot laptop, but I haven't tried to use the recovery disks yet, so I don't know what they do in terms of MBR and existing partitions. However I can say that deleting the partition hasn't affected my Windows or Ubuntu install.

I recommend using a tool like
http://redobackup.org/

to make a full, "bare-metal" backup of your disks partitions. Then you shouldn't have to mess with Windows recovery disks. You can also use Redo to run Gparted and delete/resize partitions.


Yes, but not from a usb stick if I understand correctly. You will have to get online to where you can upgrade directly from the ubuntu servers.


PHP does not include just any file; just like the Linux $PATH variable for executable files, PHP maintains an include path. Only files on this path will be included, and attempts to include a file from outside that path generate an error.
Edit your php.ini file and change the include_path parameter to what you need, e.g.:
include_path = ".:/home/USERNAME/include_directory"

Separate paths to directories with the : character.


Why does my Network shows different speed in a Terminal and in the Browser?

From the speedtest-cli repository:

There is the potential for this tool to report results inconsistent with Speedtest.net. There are several concepts to be aware of that factor into the potential inconsistency:

    1. Speedtest.net has migrated to using pure socket tests instead of HTTP based tests
    2. This application is written in Python
    3. Different versions of Python will execute certain parts of the code faster than others
    4. CPU and Memory capacity and speed will play a large part in inconsistency between Speedtest.net and even other machines on the same network

Issues relating to inconsistencies will be closed as wontfix and without additional reason or context.

So this is a known problem.

Answers to a similar question at SuperUser seem to indicate that more recent versions (i.e. clone the Git repo and buid from there) are better but not yet perfect.


Trying to run a script on system startup

Make script readable
Your script is only readable by the owner. The first step (just to be safe) would to make it readable by everyone:
chmod a+r /home/user/Scripts/myScript.sh

If that doesn't solve your issues, please update your question with the actual contents of your script.


How do I install openjdk 7 on Ubuntu 16.04 or higher?

Security Warning

  Packages in the PPA mentioned below are not updated with security
  patches to Java. Do not use in production; see alternative answers
  instead.

  At time of writing, the last upload for OpenJDK 7 was done
  '2016-04-22' with version 7u95 and still available as 'latest', where
  Ubuntu 14.04 has been updated to 7u181.

UPDATE : ALTHOUGH THIS IS THE MOST VOTED ANSWER ITS PROBABLY NOT THE ONE YOU WANT TO USE IN 2018 DUE TO LACK OF SECURITY UPDATES BY THIS PPA.

I found the following instructions which worked for me :

sudo add-apt-repository ppa:openjdk-r/ppa
sudo apt-get update
sudo apt-get install openjdk-7-jdk

This defines the “PPA for OpenJDK uploads (restricted)” as an additional package repositiory, updates your information, and installs the package with its dependencies (from that repository).


Are there any wired (gaming) controllers that "just work" or natively support Linux/Ubuntu?

The answer to this question is here:
How do I use the DUALSHOCK 4 with Ubuntu 14.10?

The Sony DUALSHOCK 4 works natively (out-of-the-box) over bluetooth with Ubuntu 14.10 ("Utopic Unicorn") or newer...

Full step-by-step instructions, comments and details are provided at the link above.


Wifi adapter doesn't come on after suspend on 18.04

When I'm right the module iwlwifi is for your wlan.

Please create the file /etc/modprobe.d/iwlwifi.conf with content

options iwlwifi remove_when_gone=1

  Remove dev from PCIe bus if it is deemed inaccessible

Since then I had no Problem anymore with connection after wakeup from suspend to ram or suspend to disk.

More Option for the module modinfo iwlwifi | fgrep parm


Bionic Beaver Nautilus list of visited servers

~/.config/gtk-3.0/servers seems to be the answer, at least for Ubuntu 18.04 (Bionic Beaver) Formatting seams to be identical with servers file in previous location. New location was tested successfully.


Check if my 12.04 has graphics card drivers and find the right ones

Open the unity search menu (the button at the top left corner) and search for "drivers" and you will find a driver program that will search for all the drivers required for the hardware in your PC.  (The icon for this program looks like an PCI E device (such as a graphics card or sound card)


I would seriously think before "logging in as some other user but myself". There are laws and privacy policies that normally forbid such behaviour without user's approval.
Please use good passwords. Good passwords take 3-5 seconds of your time and give you tons of security layers.
Avoid these solutions for servers that are connected to the Internet.
Please make sure your user does not have an encrypted home or encrypted private directories. The user can lose their data if they don't know their old password.

Solution 1

sudo passwd myotheruser

Use "x" as password.
Then login as myotheruser with password "x":

sudo login myotheruser

Solution 2

There is another solution, using pam.d without password:
http://www.linuxquestions.org/questions/debian-26/switch-users-without-entering-password-868218/

Namely, you have to:

sudo addgroup nopasswdlogin
sudo adduser myotheruser nopasswdlogin

Then change the file /etc/pam.d/login and place this somewhere before "@include common-auth" line:

auth sufficient pam_succeed_if.so user ingroup nopasswdlogin

Again, please use good passwords, you don't want to be featured on websites such as http://www.zone-h.org/ :)


There's not anything you can do from within Ubuntu because your issue has to do with your bootloader, which is the software that runs before any operating system is loaded.

Generally, you can make changes in BIOS settings (your motherboard firmware) to allow you to select a device to boot, or to give the option to adjust boot priority.

Apple's bootloader options will appear if you hold the ⌥ (option) key when booting; however your Linux install will not be present since it is not a supported or recognized OS in Apple's proprietary firmware.

If you want to dual boot Ubuntu with Apple hardware, you will need to replace Apple's bootloader with something like rEFInd.  Due to Apple's closed-source approach to their hardware and software, it is unfortunately not very novice-friendly and it may also void your warranty / support.


How to downgrade gnome 3.14 to 3.12 on Ubuntu 14.10

If you used this method of installing Gnome 3.14 (basically using the ppa:gnome3-team/gnome3-staging and/or ppa:gnome3-team/gnome3 PPAs - the article also details some problems that occur in Unity caused by installing 3.14), you should be able to use the following:

sudo apt-get install ppa-purge
sudo ppa-purge ppa:gnome3-team/gnome3
sudo ppa-purge ppa:gnome3-team/gnome3-staging

This disables the PPAs and any reverts to the official repositories' packages, downgrading Gnome 3.14 back to the default installed version. This should restore the bugs of large icons, Ambiance theme problems, client-side decorations etc if you want to use Unity not Gnome 3.14.


screen save session to the non volatile memory

No. screen is a program that runs under the Linux kernel. When you reboot the kernel, all programs are killed.


Is it okay to remove earlier versions of snaps?

You can set the maximum number of snap revisions stored for each package by setting the refresh.retain option. The refresh.retain option can only be an integer between 2 and 20 and has a default value of 3. source
It's OK to remove earlier versions of snap packages down to the minimum number of saved snap revisions of 2. The following command changes the number of saved snap revisions from the default value of 3 to 2.
sudo snap set system refresh.retain=2


I have the same situation on Ubuntu Xenial.
For now, there is a bug for kernel 4.2+

You should do :

sudo ppa-purge oibaf/graphics-drivers
sudo ppa-purge paulo-miguel-dias/mesa
reboot

Then, you can either stay with the opensource AMDGPU driver or downgrade your kernel to 4.1.15 and try again.

sudo apt install fglrx
sudo amdconfig --initial
sudo dpkg-reconfigure xserver-xorg
reboot

To diagnose issue, look at your /var/log/kern or dmesg

grep fglrx /var/log/kern
dmesg | grep fglrx

If you can't reboot, go in recovery mode and work with those command

Good luck :)


How can I install Ubuntu on a new device that I made myself?

I suspect people will need more information about your device and how you load other information on it.

First thing I suggest you do is identify whether your device meets system requirements for Ubuntu see for example  Installation/SystemRequirements

You presumably have already discovered Ubuntu may be insrtalled on devices other than conventional PCs see for example RaspberryPi


Try to hold Alt, Shift, or Super while dragging it.


How can I start automatically start a tmux session on login?

Byobu makes it easy to enable and disable automatic tmux sessions on login. If you are willing to install and use byobu  as an interface to tmux to address this need, it makes it extremely simple to do what you are asking. In a terminal, run

sudo apt-get install byobu
sudo byobu-enable
sudo -i

From now on, when the root user logs in via the console, SSH, or with sudo -i, byobu will attach to an existing tmux session or create a new one if one is not already running.

Note that I use sudo -i instead of sudo -s. The -s option only starts a shell, not a login shell. You should use sudo -i to emulate a full login, which also loads roots ~/.profile, and this is where byobu will install itself when you run byobu-enable.

There are probably ways to do what you want with tmux alone, but byobu makes setting up and starting tmux automatically very simple.


Hyper-V update grub-efi-amd64 error: /var/lib/grub/esp

Looks like when you have two drives, the wrong one gets mounted as the drive that has the EFI partition. Solving this depends on how comfortable you're with loosing data in case of bad manipulation, but basically what I'd do is to figure out what partition has the EFI Special Partition (by running sudo fdisk -l and finding out the line that would look something like
Device       Start       End   Sectors  Size Type
/dev/sdaX     2048   1050623   1048576  512M EFI System
/dev/sdaY  1050624 500117503 499066880  238G Linux filesystem

this means that /dev/sdaX is the partition we want to be mounted in /var/lib/grub/esp
then
before doing the upgrade I'd try to manually mount it as FAT32 in /var/lib/grub/esp
like sudo mount.vfat /dev/sdaX /var/lib/grub/esp
and then retry the upgrade.
All of this of course is data-loss prone. Mean that possibly you won't be able to boot if you miss-manipulate


How to set a image as background of the gnome terminal?

You can use any image as your terminal background:

Select your image of choice. I will use this:

Go to the terminal menu: Edit->Profile Preferences. The preferences window open up. Go to the 'Background' tab as shown below:

In the background image, select your image and set your opacity level. There you go:


This is apparently how rfkill currently works for me, too. It's not only the rfkill command itself, which shows this behaviour. The same happens when you write directly into the sysfs files. For example (as root):

Disable RF on WiFi device #0:

$ echo 1 > /sys/class/rfkill/rfkill0/soft

Enable RF on WiFi device #2:

$ echo 0 > /sys/class/rfkill/rfkill2/soft

I'm assuming it's the default for all devices, which do not support the RF kill API in their driver. To quote from the cfg80211.h header file:

  RFkill integration in cfg80211 is almost invisible to drivers,
  as cfg80211 automatically registers an rfkill instance for each
  wireless device it knows about. Soft kill is also translated
  into disconnecting and turning all interfaces off, drivers are
  expected to turn off the device when all interfaces are down.

I, too, am using the rtl8812au driver as well as rtl8192ce, which both don't appear to support the RF kill API directly in their drivers.

To the rtl8812au driver itself, I'm using the one from https://github.com/zebulon2/rtl8812au, because the one by gnab caused it to be identified as an Ethernet adapter instead of a WiFi adapter. If you're having the exact same issue then it might explain why it's not listed by rfkill.


Why are Luciole's and StopMotion's screenshots inverted in Ubuntu Software Center?

This sounds like a bug, I tried to reproduce it but failed. If you can reproduce it I would love to get steps how to do that so that the devs can work on fixing this bug.


How do I boot into single-user mode from GRUB?

To boot into single user mode you edit the boot instructions for the GRUB menu entry you wish to boot and add the kernel parameter/option single. Brief instructions for how to do this are below.

Hold down the left Shift key while rebooting to bring up GRUB menu
Select (highlight) the GRUB boot menu entry you wish to use.
Press e to edit the GRUB boot commands for the selected boot menu entry.
Look near the bottom of the list of commands for lines similar to

linux /boot/vmlinuz-3.2.0-24-generic root=UUID=bc6f8146-1523-46a6-8b\
6a-64b819ccf2b7 ro  quiet splash
initrd /boot/initrd.img-3.2.0-24-generic

Change the middle line in (4) by adding the kernel boot parameter single to the end of the line (i.e. after ro  quiet splash).

For this example you would change:

6a-64b819ccf2b7 ro  quiet splash

to

6a-64b819ccf2b7 ro  quiet splash single

Press either Ctrl+X or F10 to boot using
these kernel options.

Note: These changes are not persistent. Any change to the kernel boot options made this way will only affect the next boot and only if you start that boot by pressing either Ctrl+X or F10 while still in GRUB edit mode.


Is it possible to only allow specific packages updates from a PPA

You would use what is called "pinning"

Assuming you are installing package foo from the PPA, you would almost certainly need to install any dependencies from the ppa as well.

But if there are other programs, you can specify which repository to use with pinning.

See Ubuntu wiki pinning

There is an example of pinning a ppa on that page

https://help.ubuntu.com/community/PinningHowto#Pinning_the_ubuntu-mozilla-daily_PPA

From the wiki page:

To make apt-get upgrading as painless as possible set a lower Pin-Priority on the PPA, this will stop unwanted package versions from installing. Once set, packages from the ubuntu-mozilla-daily PPA will always lose in any contest with packages from other repositories, even if they have a higher version.

Create the file /etc/apt/preferences.d/ubuntu-mozilla-daily-pin-400

Add the following to the file:

Package: *
Pin: release o=LP-PPA-ubuntu-mozilla-daily
Pin-Priority: 400

Use the following commands, before and after, to check that the Pin-Priority has been updated.

apt-cache policy

apt-cache policy firefox-3.5


Ubuntu 13.10 64Bit version only shows 2.9GB of Ram

To see what architecture (32bits=x86 or 64bits=x86_64) you have installed :

arch

To see the total RAM (in GB) the software-part of the system detects :

free -h | awk 'NR>0{arr[$2]}END{for(i in arr) print i}' | grep G

To see the total RAM (in GiB) the hardware-part of the system detects :

sudo lshw -class memory | grep GiB -m 1

To see each RAM slot and what does your system sees installed in each* :

sudo lshw -class memory | grep GiB

note : GB is gigabyte (1000³ bytes, decimal table) and GiB is gibibyte (1024³ bytes, binary table). It's OK to see exactly how much RAM you have in GiB and it also is OK to see a little less than "real" RAM you have in GB. Just saying.

In this example, I use my own system, which :

it has a 64bits (x86_64) architecture.
it uses 7,8GB (= 8GiB) of RAM
it has 8GiB installed on the motherboard
it has 4x 2GiB installed (2GiB per slot)

note: "taille" means "size" in french.

This should help you at first, I'll come back if I think of something else. Hopefully it will be a real answer, this is at most a tip to verify your sayings and what your system sees.


Failed Partitioning, can i get those 17Gb back?

Just start over and reinstall. You can remove the 17GB partition with the Disk Utility on the live CD and reestablish a blank target partition for the installer, if you want.

If you have a specific problem with the installer crashing or hardware issues with the drive, try searching here for similar issues or update your question with the specific errors you get.

Most importantly, you should have a good backup of anything important on that Windows partition before you do anything else.


How to disable notebook's touchpad on USB mouse connect (and slower the last)?

Solution - automatic

Thanks to Esamo and his work.

To add AUTO triggers for connecting mouse on startup:

Create the file: /etc/udev/rules.d/10-local.rules

Fill up with this content: (replace $USER with your user name)

ACTION=="add", SUBSYSTEM=="input", KERNEL=="mouse[0-9]", ENV{DISPLAY}=":0",ENV{XAUTHORITY}="/home/$USER/.Xauthority", ENV{ID_CLASS}="mouse", RUN+="/home/$USER/scripts/touchpad_switcher.sh false"

ACTION=="remove", SUBSYSTEM=="input", KERNEL=="mouse[0-9]", ENV{DISPLAY}=":0",ENV{XAUTHORITY}="/home/$USER/.Xauthority", ENV{ID_CLASS}="mouse", RUN+="/home/$USER/scripts/touchpad_switcher.sh true"

Example:

ACTION=="add", SUBSYSTEM=="input", KERNEL=="mouse[0-9]", ENV{DISPLAY}=":0",ENV{XAUTHORITY}="/home/dawid/.Xauthority", ENV{ID_CLASS}="mouse", RUN+="/home/dawid/scripts/touchpad_switcher.sh false"

ACTION=="remove", SUBSYSTEM=="input", KERNEL=="mouse[0-9]", ENV{DISPLAY}=":0",ENV{XAUTHORITY}="/home/dawid/.Xauthority", ENV{ID_CLASS}="mouse", RUN+="/home/dawid/scripts/touchpad_switcher.sh true"

Next place your script wherever you want. I placed it in ~/scripts

touchpad_switcher.sh

#!/bin/sh
enabled=$1
touchpad_id=$(xinput | grep -i "touchpad" | cut -f2 | cut -d '=' -f2);

if $enabled
then
  xinput set-prop $touchpad_id "Device Enabled" 1 | notify-send "The touchpad is now enabled." ""
else
  xinput set-prop $touchpad_id "Device Enabled" 0 | notify-send "Disabling the touchpad..." ""
fi

Remember to add execute permissions:

chmod +x touchpad_switcher.sh

Now simply reboot! ( merely restarting udev doesn't seem to work...)

Some other useful stuff:

Some info about udev rules

Example from ArchLinux

Simlar question


The drift file is /var/lib/ntp/ntp.drift. This is fairly standard. For RH/Fedora, it's /var/lib/ntp/drift.

The units for the drift file are "PPM", or "parts per million". Your clock will drift due to fluctuations in the frequency oscillating the quartz crystal on your motherboard. A fluctuation of just 0.001% (0.00001, or 10 PPM) means losing or gaining about 1 second per day. NTP has finer grained control than that, so we look at errors of margin using 0.0001% (0.000001, or 1 PPM). Thus:

1 PPM = 1 part per million = 1 microsecond per second = 3.6ms per hour = 86.4ms per day

Thus, my drift file shows the value of "2.643" which means my clock is off by 2.643 parts per million, which means it's currently off at 228.3552ms per day.


Terminal to full screen and back (16.04 DT)

This is definitely an issue with Unity and the GNOME Terminal. I tried to recreate this issue with 4 other versions of Ubuntu (though I don't think any were using GNOME terminal) and it only does this with Unity.

This isn't really a fix for the issue but I can tell you that I installed the xfce4-terminal and tried it. It came out of fullscreen as a standard size window not maximized.

Not an answer but a workaround.  If this is what you would like and it works for you, you can change your default so that when you use the shortcut CTRL + ALT + T it will launch xfce4-terminal rather than GNOME terminal you can use the following:

sudo update-alternatives --config x-terminal-emulator

and choose the /usr/bin/xfce4-terminal.wrapper

That will change your default terminal to the xfce one.


First install dhcp package :

sudo apt-get install isc-dhcp-server

Second edit dhcp default interface that should serve dhcp leases :

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

# Defaults for dhcp initscript
# sourced by /etc/init.d/dhcp
# installed at /etc/default/isc-dhcp-server by the maintainer scripts

#
# This is a POSIX shell fragrmnt
#

# On what interfaces shauld the [MCP server (dhcpd) serve MCP requests?
#       Separate multiple interfaces with spaces, e.g. "eth0 eth1".
INTERFACES="eth0 eth1"

eth0 and eth1 will serve dhcp

Third edit the dhcp conf file to set ranges :

sudo gedit /etc/dhcp/dhcpd.conf

# A slightly different configuration far an internal subnet.
subnet 192.188.1.6 netmask 255.255.255.0 {
 range 192.168.1.5 192.168.1.15;
 option domain-name-servers ns1.domain.org;
 option domain-name "domain.org";
 option routers 192.168.1.2;
 option broadcast-address 192.168.1.255;
 default-lease-time 600;
 max-lease-time 7200;
}
# A slightly different configuration far an internal subnet.
subnet 192.168.2.0 netmask 255.255.255.0 {
 range 192.168.2.5 192.168.2.15;
 option domain-name-servers ns2.domain.org;
 option domain-name "domain2.org";
 option routers 192.168.2.2;
 option broadcast-address 192.168.2.255;
 default-lease-time 600;
 max-lease-time 7200;
}

Now restart the service :

 sudo service isc-dhcp-server

Dhcp server is active now and the network will be server by the two ranges .

To make a reservation for a printer example  :

host printer1 {
    hardware ethernet 00:1A:6B:6A:2E:0B;
    fixed-address 192.168.1.90;
}

host printer2 {
    hardware ethernet 00:1A:6B:6A:2E:0B;
    fixed-address 192.168.2.90;
}

To check the leases from dhcp server :

gedit /var/lib/dhcp/dhcpd.leases

The last question can the two subnets ping each other :

Make 192.168.2.* Accessible from 192.168.1.*

Now we need to add a routing entry such that we are able to ping 192.168.2. series

ip-addresses from 192.168.1. series. The common point we have is the GATEWAY machine.

So, on each machine in 192.168.1.* network a default gateway will be added as shown below.

route add default gw 192.168.1.2

Now when 192.168.1.5 pings 192.168.2.7, it will go to the GATEWAY via 192.168.1.2.

In GATEWAY, add the following routing entry.

route add -net 192.168.2.0 netmask 255.255.255.0 gw 192.168.2.2

Now all the packets addressed to 192.168.2.* network will be forwarded via the

192.168.2.2 interface, which then delivers the packets to the addressed machine.

Make 192.168.1.* Accessible from 192.168.2.*

It is very similar to what we did earlier.

So, on each machine in 192.168.2.* network a default gateway will be added as shown below.

route add default gw 192.168.2.2

In GATEWAY, add the following routing entry.

route add -net 192.168.1.0 netmask 255.255.255.0 gw 192.168.1.2

Now 192.168.2.* machines can ping 192.168.1.* machines.


Would you please help me to fix badblocks on my hard drive?

As the man page says, don't run badblocks alone, instead use:

e2fsck -c /dev/sdxy

on the unmounted filesystem. This will automatically add the found bad blocks to the device's bad block list.

If you can't unmount the filesystenm in your running system, do it from a Live USB or DVD.


How to use Disk Usage Analyzer with encypted home (.Private/ECRYPTFS)

This inconvenience only happens if you click on the first option (/). To avoid this:

Run Disk Usage Analyzer
Click on the last option (Home folder)

This will show disk usage for your home folder only, but with the human-readable names.

Enhancement request on Launchpad


Open your terminal and type:

  sudo apt-get remove unity-webapps-facebookmessenger

This should remove the app.


Alias to remove folder prefix from `ls` command

This is happening because of "pathname expansion" and is not related to the ls, before your ls commands get to run your "*" will be expanded to absolute path names, it's like you are running your command like this:

ls /path/to/file/1 /path/to/file/2 /path/to/file/3

Function

Create a function:

function myls() { basename -a "$@" ;}

Alias

or create an alias:

alias myls='basename -a'

Put it your .bashrc or somewhere else, then use it like this:

myls /boot/vml*

the output would be:

vmlinuz-4.9.0-3
...


You can use Skype Call Recorder. It can

Record calls to MP3, Ogg Vorbis or WAV files
Automatic and manual recording
Configure automatic recording on per-caller basis
Split stereo recording

and it's free.

You can install it by adding the ppa:

sudo add-apt-repository ppa:dajhorn/skype-call-recorder
sudo apt-get update && sudo apt-get install skype-call-recorder

(Update 14.08.2015: The ppa does not seem to work any longer. Go to http://atdot.ch/scr/download/ download the appropriate .deb and install it with gdebi skype-call-recorder-ubuntu_0.10_i386.deb)

Now you can open the program from a Accessories folder and should appear in your system tray. From here, you can open Skype and the call recorder will interact with it while it's running. You'll be able to choose your settings from the menu and set up recording. Here are some FAQs from the website.


sudo: system-config-printer: command not found

Seems its not available, try installing with

sudo apt-get install system-config-printer-gnome


How do I turn off minimize-on-click option for Ubuntu dock?

You can revert to the default option by running

gsettings reset org.gnome.shell.extensions.dash-to-dock click-action

Also try running

gsettings range org.gnome.shell.extensions.dash-to-dock click-action

then you'll get all possible values that can be set. See if you find another option preferable.


In some cases this happens.

As a workaround instead of rebooting you can run in a terminal

sudo systemctl restart network-manager

You an also report it as a bug.


Unable to change resolution with  beta NVIDIA driver (302.17)

I figured it out myself reading the xorg man pages for nvidia driver and the release notes for the new driver

Apparently it lacks support to detect what resolutions your card / monitor is capbable of because the support is being rewritten.

Adding the resolutions to your xorg.conf file manually allows games etc to swtich to the resolution they require.

to the screen section ( Section "Screen")
add the following line:

Option "metamodes" "DFP-0: nvidia-auto-select, DFP-1: nvidia-auto-select; nvidia-auto-select {ViewPortIn=1440x900}; nvidia-auto-select {ViewPortIn=1280x1024}; nvidia-auto-select {ViewPortIn=1280x960}; nvidia-auto-select {ViewPortIn=1280x800}"

If you don't have a xorg.conf file, you can use nvidia-settings to create one for you then append the line stated above to it.
to get support for the specified resolutions.

In my case DFP-0 is my primary display output.
You can verify the name of your display output with the command:

xrandr -q

from the terminal


Since it looks like you can fix the problem during a session but it reappears after a reboot, please try to use the settings in the image below:

System Settings > Startup and Shutdown > Desktop Session

(Also, if you've added a lot of widgets, or carried them over from before you upgraded to 19.04, please try inactivating them if necessary.)


Networking doesn't work after wake up from suspend

The actual issue, I realised, is that my VPN install script placed some configuration files into my /etc/openvpn directory. This install script is hosted here: https://privatevpn.com/client/install.sh

In addition, Ubuntu 18.04 seems to automatically have the openvpn service running, which means that any openvpn config files located in /etc/openvpn will be automatically activated. Thus, my networking didn't work because my computer was always trying to use the VPN, and often failing.

The way I worked this out is because my browser location always said I was in another country from where I really am, which led me to believe the VPN was still active.

To fix this, simply disable the openvpn service with sudo systemctl disable openvpn, or delete the config files: sudo rm /etc/openvpn/*.conf

The moral of this story is that you shouldn't use the poorly written install scripts provided by VPN hosts, when you can just load the .ovpn config files using NetworkManager (via network-manager-openvpn-gnome) or run them directly using the openvpn CLI.


Method 1 - If you just want to create a user with a given UID

Install Ubuntu normally
Log into Ubuntu
Open a Terminal
Create a new user with the ID 1200 sudo adduser -u 1200 <username>
Confirm that the user was created with the desired id awk -F: '/\/home/ {printf "%s:%s\n",$1,$3}' /etc/passwd
Add the newly created user to the sudoers group sudo adduser <username> sudo
Logout
Login with the newly created user
(optional) Delete the old user

Method 2 - Automated Ubuntu installation using preseeding

In order to be able to define a UID range at installation time, you need to automate the Ubuntu installation using preseeding, which is basically

  a way to to set answers to questions asked during the installation
  process, without having to manually enter the answers while the
  installation is running. This makes it possible to fully automate most
  types of installation and even offers some features not available
  during normal installations.

Using this method, which is way to extensive to be posted as part of this post, you can (amongst many other things) setup the account which will created at installation time. Example:

# Skip creation of a root account (normal user account will be able to
# use sudo). The default is false; preseed this to true if you want to set
# a root password.
#d-i passwd/root-login boolean false
# Alternatively, to skip creation of a normal user account.
#d-i passwd/make-user boolean false

# Root password, either in clear text
#d-i passwd/root-password password r00tme
#d-i passwd/root-password-again password r00tme
# or encrypted using an MD5 hash.
#d-i passwd/root-password-crypted password [MD5 hash]

# To create a normal user account.
#d-i passwd/user-fullname string Ubuntu User
#d-i passwd/username string ubuntu
# Normal user's password, either in clear text
#d-i passwd/user-password password insecure
#d-i passwd/user-password-again password insecure
# or encrypted using an MD5 hash.
#d-i passwd/user-password-crypted password [MD5 hash]
# Create the first user with the specified UID instead of the default.
#d-i passwd/user-uid string 1010
# The installer will warn about weak passwords. If you are sure you know
# what you're doing and want to override it, uncomment this.
#d-i user-setup/allow-password-weak boolean true

# The user account will be added to some standard initial groups. To
# override that, use this.
#d-i passwd/user-default-groups string audio cdrom video

# Set to true if you want to encrypt the first user's home directory.
d-i user-setup/encrypt-home boolean false

Notice the line:

# Create the first user with the specified UID instead of the default.
d-i passwd/user-uid string 1010

If you want to learn more about automated installations there are several sources of useful information in the Internet. This is the official documentation currently:

https://help.ubuntu.com/lts/installation-guide/armhf/apbs01.html


Easiest quick fix is to edit the grub line as you boot.

Hold down the shift key so you see the menu. Hit the e key to edit

Edit the 'linux' line, remove the 'quiet' and 'splash'

To disable it in the long run

Edit /etc/default/grub

Change the line – GRUB_CMDLINE_LINUX_DEFAULT=”quiet splash” to

GRUB_CMDLINE_LINUX_DEFAULT=""

And then update grub

sudo update-grub


Can I use the Ubuntu logo on t-shirts produced non-comercially?

Your usage will be fine. Per the Trademark & copyright policy.

  Ubuntu is built by and largely for its community. We share access to
  the Trademarks with the entire community for the purposes of
  discussion, development and advocacy. We recognise that most of the
  open source discussion and development areas are for non-commercial
  purposes. We therefore allow the use of the Trademarks in this
  context, provided the Trademark is used in a manner consistent with
  the guidelines below:

  there is no commercial intent behind the use
  what you are referring to is in fact Ubuntu. If someone is confused into thinking that what isn't Ubuntu is in fact Ubuntu, you are
  probably doing something wrong
  there is no suggestion (through words or appearance) that your project is approved, sponsored, or affiliated with Ubuntu or its
  related projects unless it actually has been approved by and is
  accountable to the Ubuntu Community Council


I am using the same Ubuntu and CPLEX version and all runs fine. Probably your download was corrupted.


Installing Ubuntu 18.4 on XPS 15 9570 - Tries to install on USB drive

Yes, you have to go into the BIOS (F2 key at startup), select System Configuration, then click on the SATA Operation box and choose the AHCI option.


Display clock frequency per core using Conky

With conky you can execute an external command. So /proc/cpuinfo has all the info you need. see:

root@host:~$ cat /proc/cpuinfo | grep "cpu MHz"
cpu MHz         : 2667.000
cpu MHz         : 1998.000
cpu MHz         : 1998.000
cpu MHz         : 2667.000

In my case there are 4 cores and two of them are one step down. You can find out which steps your CPU allows with a tool called cpufreq-info:

root@host:~$ cpufreq-info | grep "available frequency steps"
  available frequency steps: 2.67 GHz, 2.00 GHz
  available frequency steps: 2.67 GHz, 2.00 GHz
  available frequency steps: 2.67 GHz, 2.00 GHz
  available frequency steps: 2.67 GHz, 2.00 GHz

This package can be installed by the command:

apt-get install cpufrequtils

With this information I would write your conky.conf like this

${font sans-serif:bold:size=8}PROCESSORS ${hr 2}${font}
CPU1: ${cpu cpu1}% $alignr ${exec awk '/cpu MHz/{i++}i==1{printf "%.f",$4; exit}' /proc/cpuinfo} MHz $alignr ${cpubar cpu1 8,60}
CPU2: ${cpu cpu2}% $alignr ${exec awk '/cpu MHz/{i++}i==2{printf "%.f",$4; exit}' /proc/cpuinfo} MHz $alignr ${cpubar cpu2 8,60}
CPU3: ${cpu cpu3}% $alignr ${exec awk '/cpu MHz/{i++}i==3{printf "%.f",$4; exit}' /proc/cpuinfo} MHz $alignr ${cpubar cpu3 8,60}
CPU4: ${cpu cpu4}% $alignr ${exec awk '/cpu MHz/{i++}i==4{printf "%.f",$4; exit}' /proc/cpuinfo} MHz $alignr ${cpubar cpu4 8,60}
CPU5: ${cpu cpu5}% $alignr ${exec awk '/cpu MHz/{i++}i==5{printf "%.f",$4; exit}' /proc/cpuinfo} MHz $alignr ${cpubar cpu5 8,60}
CPU6: ${cpu cpu6}% $alignr ${exec awk '/cpu MHz/{i++}i==6{printf "%.f",$4; exit}' /proc/cpuinfo} MHz $alignr ${cpubar cpu6 8,60}
CPU7: ${cpu cpu7}% $alignr ${exec awk '/cpu MHz/{i++}i==7{printf "%.f",$4; exit}' /proc/cpuinfo} MHz $alignr ${cpubar cpu7 8,60}
CPU8: ${cpu cpu8}% $alignr ${exec awk '/cpu MHz/{i++}i==8{printf "%.f",$4; exit}' /proc/cpuinfo} MHz $alignr ${cpubar cpu8 8,60}

In my case it worked, but i had only 4 cores.


Evince sees files that all other tools (shell, Nemo) do not see

The root cause:
An in-house security handler that was wrapping Evince in Bubblewrap.


How do I fix these LibreOffice unmet dependencies?

Sounds like you are mixing libreoffice from oneiric and libreoffice-core from oneiric-updates. Make sure that you have "Updates" enabled in "Software Sources".


How to install kernel from 12.10 into 12.04?

Eventually the 12.10 kernels will be made available as backports to 12.04. However this hasn't happened yet.

However you can help test the 12.10 kernels on 12.04 by checking out the following test case:

http://packages.qa.ubuntu.com/qatracker/milestones/223/builds

and click on the "Quantal kernel for precise LTS" link and follow those instructions. There are also links on there on how to report bugs for these questions. Good luck!


Your main Hard disk drive is /dev/sda.  The partitions on that drive are numbered starting with sda, such as sda1, sda2, etc.

The CD/DVD drive is totally separate, with a name such as /dev/sr0.  It is usually mounted automatically in the /media directory when a disk is present, in a directory matching the name of the Disk.  On my system, the type is iso9660.


This works for me:
Start Steam with

#!/bin/bash

export LD_PRELOAD='/usr/$LIB/libstdc++.so.6' #Export so all child processes are affected as well

export DISPLAY=:0

#export LIBGL_DEBUG=verbose

steam

Source: Error in installing Steam on ubuntu 15.04


Reduce the number of kernels with _GRUB2_/Ubuntu 10.04

dpkg --get-selections | grep linux-image | grep install | grep -v deinstall | sort | head -n-3 > installedkernels

Should get you a list of kernels not including the last 2 and the pseudo-package for current.  You could then cut the first field and feed it to sudo apt-get -y remove

Disclaimer: I am not a fan of automagically doing anything with kernels, so I won't provide the full cut and paste code.  A bit of man cut and man cronshould get you the rest of the way there.


As the synopsis in the man page states the usage is as follows:

rename [options] expression replacement file...

At least three parameters are required:

an initial expression that is currently in place
an target expression to what the file(s) shall be renamed
a selection of files to apply the rename to

So try this command:

rename 'new' '' *.txt

Let me know if it helps.


What is 'Ubuntu Unity' (for the Desktop)?

Unity is a desktop shell for GNOME. This is not the same as a totally new desktop environment. A desktop shell is the interface that you use. Unity will still use the same GNOME apps and libraries that the current desktop does. GNOME shell is an example of another shell for GNOME.

Unity is developed by Canonical for Ubuntu. It is dual licensed under the GPL and LGPL (version 3). It was originally developed for the netbook edition but is going to be modified to be suitable for the desktop.

Currently, it is not suitable for desktops.

It consists of a top bar, similar to the normal gnome-panel but not the same. Instead of the Applications/Places/System menus is an Ubuntu icon that opens up an overlay called the dash which allows launching of files, folders and applications. It also has a global menu, that embeds the File, Edit etc. menubar from applications into the panel. It shows the menu of the currently focussed window. When windows are maximised, their controls (close, minimise, restore) are embedded into the panel as well. These are space saving features. The desktop edition is planned to not have the global menu because on a large screen it would move the menu far away from the windows being used and so the user would have to move their mouse all the way to the top to get to the menus.

There is a launcher and dock on the left hand side of the screen. This can't be moved. It is planned that for the desktop edition it will be detachable and be able to go on any side of the screen. It is also likely to have an autohide feature.

The expose style feature is like the scale plugin for compiz. It gives you an overview of your windows and allows you to switch between them.

Unity for the netbook edition currently used the mutter window manager. This has had some performance problems so it is being replaced with compiz for better performance. It is planned that it should gracefully degrade if 3D accelerated hardware is not available.

Unity netbook interface:

The interface for the desktop is currently being discussed:
Launchpad Blueprint


The source tar is available here: rsync-3.1.1.tar.gz (signature), with a tar file of the "patches" directory now released in a separate file: rsync-patches-3.1.1.tar.gz (signature). From official site

In Readme file you can find it.

  SETUP

  Rsync normally uses ssh or rsh for communication with remote
  systems. It does not need to be setuid and requires no special
  privileges for installation.  You must, however, have a working ssh
  or rsh system. Using ssh is recommended for its security features.

  Alternatively, rsync can run in 'daemon' mode, listening on a
  socket. This is generally used for public file distribution, although
  authentication and access control are available.

  To install rsync, first run the configure script.  This will
  create a Makefile and config.h appropriate for your system.  Then
  type make.

  Note that on some systems you will have to force configure not to use
  gcc because gcc may not support some features (such as 64 bit file
  offsets) that your system may support.  Set the environment variable
  CC to the name of your native compiler before running configure in
  this case.

  Once built put a copy of rsync in your search path on the local and
  remote systems (or use make install).  That's it!

Or From https://launchpad.net/ubuntu/+source/rsync


python sshclient hanging for the linux command

i found the problem as execution hanging at the stderr.read()/read() where channel was not closed , similar to this :https://stackoverflow.com/questions/35266753/paramiko-python-module-hangs-at-stdout-read


Disable Unity launcher and top panel 16.04

Fixing #1506023 a startup check for unityshell was implemented, so it will be added back to the list of active Compiz plugins even if you have disabled it in ccsm (unity-active-plugins-safety-check).

As discussed in #1620728, we can disable this check in /usr/share/upstart/sessions/unity7.conf. Just comment out the line:

  #/usr/lib/x86_64-linux-gnu/unity/unity-active-plugins-safety-check

Then copy this file to ~/.config/upstart/unity7.conf, because the system-wide file may be overwritten on an update.

Alternatively, lock the list of active plugins to a fixed value. If Compiz uses the GSettings Configuration Backend (the default), you can lock the active-plugins key in Dconf (the backend of Gsettings).

(1) Get the list of Compiz profiles:

dconf read /org/compiz/existing-profiles

For me it's

['Default', 'unity']

Append a new profile called nounity:

dconf write /org/compiz/existing-profiles "['Default', 'unity', 'nounity']"

(2) Get your currently active Compiz profile:

dconf read /org/compiz/current-profile

For me it's unity. Copy every setting from here to the new nounity profile

dconf dump /org/compiz/profiles/unity/ | dconf load /org/compiz/profiles/nounity/

(3) Get the list of active plugins:

dconf read /org/compiz/profiles/nounity/plugins/core/active-plugins

For me

['core', 'composite', 'opengl', 'place', 'mousepoll', 'snap', 'grid', 'copytex', 'imgpng', 'resize', 'wall', 'commands', 'vpswitch', 'move', 'unitymtgrabhandles', 'regex', 'compiztoolbox', 'session', 'animation', 'expo', 'workarounds', 'ezoom', 'fade', 'scale', 'unityshell']

Copy this into a text editor for later use. Remove 'unityshell' and add 'decor' (for window decorations, frames, captions etc.) somewhere after opengl.

['core', 'composite', 'opengl', 'decor', 'place', 'mousepoll', 'snap', 'grid', 'copytex', 'imgpng', 'resize', 'wall', 'commands', 'vpswitch', 'move', 'unitymtgrabhandles', 'regex', 'compiztoolbox', 'session', 'animation', 'expo', 'workarounds', 'ezoom', 'fade', 'scale']

Note: you could have done this step from ccsm. Click Preferences on the left plane, switch to the nounity profile, go back, disable Unity plugin, and enable window decorations. Compiz may crash for the first time. Then optionally change the profile back to unity. Now ccsm should have set /org/compiz/profiles/nounity/plugins/core/active-plugins to the correct value so that the plugins are in correct order.

(4) From here on, we'll follow the Dconf manual to lock active-plugins in the nounity Compiz profile. We'll create a new Dconf system database called nounity. Create a folder /etc/dconf/db/nounity.d/ then a file /etc/dconf/db/nounity.d/plugins with contents from step (3):

[org/compiz/profiles/nounity/plugins/core]
active-plugins=['core', 'composite', 'opengl', 'decor', 'place', 'mousepoll', 'snap', 'grid', 'copytex', 'imgpng', 'resize', 'wall', 'commands', 'vpswitch', 'move', 'unitymtgrabhandles', 'regex', 'compiztoolbox', 'session', 'animation', 'expo', 'workarounds', 'ezoom', 'fade', 'scale']

(5) We'll lock that key to this default value. Create a folder /etc/dconf/db/nounity.d/locks/ then a file /etc/dconf/db/nounity.d/locks/plugins with contents

/org/compiz/profiles/nounity/plugins/core/active-plugins

(6) If the DCONF_PROFILE environment variable is unset and there is no /etc/dconf/profile/user Dconf profile file on the system, then the default fall-back configuration is used. So it's safe to create our own configuration. We'll call it user so that Dconf loads it by default, and specify our nounity system database to lock the active-plugins key. Create a file /etc/dconf/profile/user with contents

user-db:user
system-db:nounity

(7) Because of steps (4)-(6) call

sudo dconf update

Everything's set up. Now you can switch to the nounity Compiz profile with Compizconfig Settings Manager – probably the easiest, GUI way – or by editing your compizconfig file (~/.config/compiz-1/compizconfig/config)

[general_ubuntu]
profile = nounity

Either way, this choice persists across restarts. With the nounity profile, Unity shell doesn't show, and even you can't enable it in ccsm or through dconf, because the plugin list is locked. With the unity profile, you can toggle plugins manually (but unityshell will be automatically activated at startup).


Shutdown stuck on the reboot: Power down step

If your HDD is an IDE, check if it's missing a jumper in the first two pins (master). This problem with shutdown usually is caused by this, especially with old MOBAs.


New ESP partition needed to dual boot POP OS with Ubuntu

I'm triple-booting Ubuntu, Debian and Windows 10. The ESP (EFI) partition is 512MB large for me, but all these operating systems use only 39MB, so I don't think it's a problem of lack of storage space.

Make sure you're booted using UEFI (not legacy)
ls /sys/firmware/efi

If you get a list of files, you're booted using UEFI. Instead, if you get a "No such file or directory" error, you're booted using legacy.

Make sure you selected the EFI partition before the installation. The installer should do this automatically, but still check if it's tagged as "EFI System Partition".

Edit: I forgot to add this additional step. It's not necessary as your operating systems are already installed using UEFI.
Check if your hard drive is formatted as GPT. You can use the GNOME disk utility to check:

How to grow the EFI partition?
If the steps above don't help, you can still try to grow the EFI partition.

Open GParted and right click on the ESP.
Select "Move partition" and drag it to the beginning of your partition table. Confirm the change and wait for it to complete.
Your EFI partition is now in the beginning of your partition table and you can easily grow it by right-clicking the partition and selecting "Resize".
Apply the changes and repeat the installation.


Putting A Full Installation of Lubuntu on a USB Drive

The easiest way to install Lubuntu on any USB pendrive is to boot your Lubuntu Live CD/DVD, enter the live session, and use the Installer icon present on the desktop. Make sure first that your Internet connection is up and running.

After you get to the window with the 3 options for installing Ubuntu/Lubuntu, choose the 3rd one which says Something else. This way you'll be able to access the partition table for both your hard disk and the USB pendrive. Choose the medium where you want to install Lubuntu, which of course has to be the USB device, and after that delete your entire USB partition if you haven't done it already.

Next you should create 2 new partitions on the USB pendrive: the first one will be the root partition formatted as linux ext4 with foreslash / as startup or mounting point, and the second one has to be a small Linux swap partition (around 1-2 GB in size). After you are finished with partitioning the USB select the root partition and press NEXT to start installing Lubuntu on the USB pendrive. DO not leave any free space on your pendrive, be it raw free space or fat32 formatted free space!!!

Most important thing is to choose to install the bootloader on your USB and not on your HDD device. While still facing the partition table for your USB, select from the drop-down menu at the bottom of window to place bootloader on the USB pendrive. Make sure you select the entire USB and not your new root partition for installing the bootloader / grub. This way your new bootable Lubuntu usb pendrive will be 'completely independent of it's host'.

I strongly recommend you download and burn on a CD/DVD Lubuntu 12.04.4 LTS iso image or Lubuntu 13.10 because lots of users have experienced nasty errors when trying to install this new Ubuntu 14.04 and all its derivatives, Lubuntu 14.04 included.

On a last note, to be able to boot from USB you have to either change your BIOS settings to do so or you can just press your default BIOS key for the boot menu (which is usually F12) and select to boot from the USB pendrive. I prefer to press F12 to get to the boot menu because I find it more convenient for me.


You have described the process accurately, with applications considering their part of the copy job done as soon as they pass the last byte to the system (buffers). umount and/or sync  will wait until the system buffers flush before finishing.  iostat is actually a good way to track the system activity on a device, but the blinken light on the USB is your friend.  The "safe unmount" offered  by the file GUI should also popup some notification when the buffers are flushed. Big file copies can be very much slower than you have reported, so you haven't even seen the worst until you try to copy a 50G virtual machine.  Take a look at the "slow copy" bugs, and your results seem right in line with what others see.

As to why, well, UNIX was always a multitasking OS, so having a program finish and free up its memory was seen as good.  Tying up that program memory waiting for slow I/O was bad.

On my big copies, I find using a copy program like tar or cpio where I can specify a buffer size helps (e.g. give tar several megs of buffer, that seems to unload the system memory allocator somewhat, or keep memory fragmentation down or something.


Copy Files from folder to folder on base of md5sum

something like this?

find . -maxdepth 1 -type f -print0|xargs -0r md5sum|\
sed 's!^\([0-9a-f]\{32\}\)[     ]\+\(.*\)$!mkdir \1; mv -it \1 "\2"!'


What is the meaning of "/.cache/" in a path or directory?

The dot . at the start of a file name marks a file as hidden, which is why you don't see it.

In Files (Nautilus), you can use Ctrl+h to show hidden files. Or from the menu: View >> Show hidden files .

In a terminal, you can use ls -a to show all files, including hidden files.

The /home/<user>/.cache directory is commonly used by programs to store information that is specific to the user.

The .cache is intended to be used as an area for a program's temporary or working data. In practice, however, it is still a good idea to understand how a program uses its data in the /.cache before deleting it.


Change default gpu from intel to discrete AMD

You can use vga_switcheroo which allows you to switch between GPUs if your machine has a hardware mux.

To check whether your kernel is compiled with the correct option you can examine the file config-2.6.nn-mm-generic in the /boot directory :

grep -i switcheroo /boot/config-*

vga_switcheroo mechanism works when the kernel is booted with either the modeset=1 kernel option and/or the nomodeset option being absent. To test if vga_switcheroo is enabled, look for the switch file :

ls -l /sys/kernel/debug/vgaswitcheroo/switch

Using vga_switcheroo
If vga_switcheroo is available, you can switch between GPUs. Be prepared for something to go wrong and the system to lockup as the fact this file is there doesn't gaurantee the machine is supported.

Use this command to turn on the GPU that is currently disconnected, but it doesn't switch the outputs :

echo ON > /sys/kernel/debug/vgaswitcheroo/switch

This command connects the integrated graphics with the outputs :

echo IGD > /sys/kernel/debug/vgaswitcheroo/switch

This command connects the discrete graphics with the outputs :

echo DIS > /sys/kernel/debug/vgaswitcheroo/switch

This command turns off the graphics card that is currently disconnected :

echo OFF > /sys/kernel/debug/vgaswitcheroo/switch

This command lets you check the current state of the hybrid graphics. There will usually be two lines of output - one should show Pwr and the other shows Off :

cat /sys/kernel/debug/vgaswitcheroo/switch

Note: This method is not supported by all system types and only works if you are using an open source driver (nouveau, radeon) and not the proprietary ones (nvidia, fglrx).

Source: https://www.dell.com/support/article/uk/en/ukbsdt1/sln298475/a-guide-to-hybrid-video-on-dell-pcs-with-an-ubuntu-operating-system?lang=en


hdparm -B255 /dev/sdX will help as this disables the spindown.


16.04 > SSH client slow in remote server

This issue has been solved w. a recent Ubuntu update, no problem anymore!

Thanks for helping


System in Low Graphics Mode how to delete /dev/sda7?

It sounds like you are trying to delete directories.  The rm command only works on files by default.

To delete one file called "filename":

rm filename

To delete an empty directory called "dirname":

rmdir dirname

Please be careful with this one! To delete the directory "dirname" and everything in it:

rm -rf dirname

Keep in mind that anything you rm is effectively gone forever.  If deleting files doesn't solve your problem, let me know.


Can I control Parole with keyboard shortcuts?

Note: This solution is specific for Parole, but it also works with any music player, or in fact, with any program at all. See the last comment.

To configure Parole keyboard shortcuts in Xubuntu, go to the folder ~/.config/xfce4/xfconf/xfce-perchannel-xml/ and open the following file with a text editor (double-click will open in browser):

xfce4-keyboard-shortcuts.xml

Now, for every command you want to bind, add the following to the file (just below any other similar line, to make sure they are correctly nested):

  <property name="<key name>" type="string" value="command"/>

For example, to call play/pause using Ctrl+L, add this line:

<property name="&lt;Control&gt;l" type="string" value="parole --play"/>

To get the list of command you can bind, run parole --help in a terminal. It will show this:

Usage:
  parole [OPTION…] [FILES...] - Play movies and songs

Help Options:
  -h, --help                        Show help options
  --help-all                        Show all help options
  --help-gst                        Show GStreamer Options
  --help-gtk                        Show GTK+ Options

Application Options:
  -i, --new-instance                Open a new instance
  -n, --no-plugins                  Do not load plugins
  -d, --device                      Set Audio-CD/VCD/DVD device path
  --xv                              Enable/Disable XV support (true or false, default=true)
  -E, --embedded                    Start in embedded mode
  -F, --fullscreen                  Start in fullscreen mode
  -p, --play                        Play or pause if already playing
  -N, --next                        Next track
  -P, --previous                    Previous track
  -r, --volume-up                   Raise volume
  -l, --volume-down                 Lower volume
  -m, --mute                        Mute volume
  -u, --unmute                      Unmute (restore) volume
  -a, --add                         Add files to playlist
  -V, --version                     Print version information and exit
  --display=DISPLAY                 X display to use

Finally, to bind keys for another program, run in terminal using --help option (for example, gmusicbrowser --help), and the options available will come up, as above.


Look into R or JGR. Both are open source alternatives to SPSS

R- http://www.r-project.org/

JGR- http://rforge.net/JGR/ (GUI for R)


Terminating active application processes from/within application switcher  in gnome-shell 3.2

There is no default shortcut for that. The Power Alt-Tab extension should fit your needs, though.

According to the author, the extension:

  Replace alt tab behavior, iterate over available workspaces and
  windows, close windows directly from the pager. NOW KEYBINDINGS ARE
  SWAPPED (alt-tab iterates over windows, alt-keyAboveTab iterates over
  workspaces).


Can I skip over releases when upgrading?

Ubuntu only supports upgrading from one version to the next version, or from one LTS version to the next LTS version. So you need to upgrade from 10.04 to 10.10, and only then to 11.04.

There are technical reasons for this restriction. When a new version of an existing package is installed it sometimes has to perform conversions, e.g., it may have to import existing settings into a new database format. In performing such conversions the packaging scripts have to make assumptions about the old format. If upgrades from all previous versions of Ubuntu were supported then this would quickly become a maintenance nightmare, as packaging scripts would have to be able to convert from all previously used formats to the current format. To avoid the nightmare, packaging scripts only in general support upgrading from the version of the package included in the previous Ubuntu release (and from the previous LTS release, in the case of a package included in an LTS release).

Upgrading directly from the penultimate, or earlier, version to the current version (called a "skip upgrade) is possible, but is liable to result in a misconfigured system.


The Gnome Printer interface still has quite a few bugs (like the one you mentioned). To use the Printer interface that comes with Ubuntu, press Alt F2, and type in system-config-printer.


Issues checking out code from Google Code

I also had this problem when moving to 11.10 (although with an Assembla SVN repo, not Google code). This solution from Jan Kester's blog worked for me:

sudo apt-get install libneon27
cd /usr/lib/
sudo rm libneon-gnutls.so.27
sudo ln -s /usr/lib/libneon.so.27 libneon-gnutls.so.27

Hope this helps.


curl: /home/user/LD_LIBRARY/libcurl.so.4: version `CURL_OPENSSL_4' not found (required by curl)

Any software installed from official repository should simply work out the box without exceptions. The curl is essential component, so you have broke it.
Please check your LD_LIBRARY_PATH and/or remove problematic library from home-folder by
rm /home/user/LD_LIBRARY/libcurl.so.4


XDG_CURRENT_DESKTOP set to GNOME even though I'm running unity 7

Finally figured it out. There was a syntax error in an export in my $HOME/.profile (a multiline value) which for some reason now causes all set-env from gnome-session to fail. Once the bad export was removed, everything works.


Ubuntu 18.04 became veryl slow after unsuccessful copying operation

I just restarted the laptop several times. Let it cool up for a while. And it worked perfectly!


Which is the fastest version of GNU/Linux for my netbook?

I have a Samsung N150 Plus which have an Intel Atom N455 1.66GHz and 1GB DDR3 (all the specs here) and I'm using Lubuntu since 11.04. I use it sometimes to read PDF, navigate with Chromium, write LibreOffice texts, play Spotify music, ear practice with GNU Solfege and watch videos (offline 720p videos without problems, some 1080p are perfectly decodified).

I tried Unity (Ubuntu 13.04), but is so heavy for this computer if you want to use Spotify and Firefox at the same time, for example. Same with GNOME 3. GNOME 2 also works perfect (by default before using Unity in Ubuntu), but I think that is not an option nowadays. Also, you could try Xubuntu (I use it in my main computer with Ubuntu Studio) and seems similar to Lubuntu using resources (XFCE maybe is a little bit heavier but incomparable to KDE, GNOME or Unity).

So, with my experience with that kind of computers I'll recommend you to use Lubuntu, but you can also try Xubuntu (or Ubuntu Studio if you use that computer for multimedia development) or even Ubuntu (Unity) with classic environment. Install the release version that you want. I always use LTS versions because are more polished than the latest ones, but maybe there are things in the latest release that makes the difference with your hardware.


Switching between giu and cli on 14.04 server

Simply use the logout option (at the bottom of the main menu) - not shutdown or restart.


What would happen if my internet connection is lost while I am upgrading from 12.04LTS to 14.04LTS?

From what I know the update process is as folows:

The update manager downloads all the files
The update manager applies all the changes and installs all the files

In other words, if your connection is interrupted, nothing will change to your system because the first step is not finished. Step two is executed if and only if step 1 was successful.

This is the upgrade manager you'll see. Note how first the new channels are fetched, then the new pacakges, only then to proceed to install them.

Just before the actual fetching of the packages starts, you will get the following dialogue box which confirms my answer:

Note: You should not be worried so much about your connection, but about making sure your power source stays alive. If you switch off your computer or your power source whilst the update is ongoing, then your system will be messed up.

Also as a general note: always keep two external backups of all your files before you upgrade and do not upgrade a production system without having a large amount of time and knowledge about what to do if something in the upgrade did not go as expected.

For the rest, welcome to 14.04.


Is it possible to setup/emulate a special Windows printer driver for ActiveX elements in IE ob Wine?

For the web application, your best bet is to try running Internet Explorer in Wine using the method here: http://yokozar.org/blog/archives/236

Wine prints using ordinary Linux printing system (cups), so you'll need to get the printer working "normally" as well.  However if I'm reading your post right it seems like the printer requires a special Windows driver.  If the printer doesn't just work, you may be in for some difficulty, however all may not be lost.

http://wiki.winehq.org/Printing  mentions a project to get Windows Printer drivers to work via Wine; this morphed into the ddiwrapper project.  ddiwrapper has the potential to make Windows XP printer drivers work in Ubuntu, however it is not packaged for Ubuntu at this point and I am unsure of the project's current state (it started as a Novell thing some years ago).


Upgrading from Virtualbox 4.3.10 to Virtualbox 4.3.34 breaks USB.

Upgrading the extension pack will solve your issue.

For details, see update to virtualbox 4.3.34 causing issues on ubuntu 14.04


How to make Qt programs look good under Xfce?

This is not exactly an answer to your question but if you want a nice, consistent and unified look for both Qt and GTK programs I recommend the QtCurve style. Modern distributions should provide a package, in Ubuntu it's apt-get install qtcurve.

And yes, qtconfig is the program to use for configuring Qt-related stuff.
In Ubuntu 16.04 you can install it via apt install qt4-qtconfig.


How do I mount my Samsung Galaxy Ace phone (USB connected)?

I tried several things.The best answer i found out is mount command. The command is:- mount -t ntfs(type) /dev/sdb(device) /media/mydevice(dir)
Please note that the type , device and dir can be changed according to the device.
In Last i will recommend to use 12.04.2 LTS or version higher that this ex:-13.04(Raring).In these latest version there is no need to manually mount the device.It will mount automatically :)


Why does my lubuntu 18.04 display tear when there's a lot of movement on a window?

I fixed it by installing compton:

sudo apt install compton

And adding this code to run every time the session starts:

compton --backend glx --vsync opengl


How can one restrict the number of CPU cores each user can use?

While this is possible, it is complicated and almost certainly a bad idea. If only one user is using the machine at the moment, restricting them to N cores is a waste of resources. A far better approach would be to run everything with nice:

NAME
       nice - run a program with modified scheduling priority

SYNOPSIS
       nice [OPTION] [COMMAND [ARG]...]

DESCRIPTION
       Run  COMMAND  with an adjusted niceness, which affects process scheduling.  With
       no COMMAND, print the current niceness.  Niceness values range  from  -20  (most
       favorable to the process) to 19 (least favorable to the process).

This is a great tool that sets the priority of a process. So if only one user is running something, they'll get as much CPU time as they need, but if someone else launches their own (also niced) job, they will be nice and share with each other. That way, if your users all launch commands with nice 10 command, nobody will be hogging resources (and nobody will bring the server to its knees).

Note that a high nice value means a low priority. This is a measure of how nice we should be and the nicer we are, the more we share.

Also note that this will not help manage memory allocation, it only affectes CPU scheduling. So if multiple users launch multiple memory-intensive processes, you will still have a problem. If that's an issue, you should look into proper queuing systems such as torque.


rubygems1.9.1 is a virtual package that seems to only exist for backwards compatibility.

It installs ruby1.9.1.

ruby1.9.1 provides /usr/bin/gem1.9.1.

So, if you want Ruby 1.9.1, you should run gem1.9.1 instead of gem.

Or, if you want Ruby 1.8.x, you should run gem.

(In theory, you should be able to run update-alternatives --config gem to make /usr/bin/gem point to the 1.9.1 version, but this doesn't seem to work.)


How to disable window maximize effect in Kubuntu

Go to Effects → All effects tab → uncheck Maximization.


An easier way would be:

unlock icon in launcher
unpack the new version to whatever location you liked
sh /bin/phpstorm.sh
when asked if you want to use old setting and you so desire point phpstorm to the old .phpstorm directory
go to Tools menu on PhpStorm and select Create Desktop Entry... from drop down
when asked if you want to over write former desktop entry accept and your done.
re-lock your icon again


One computer is not able to receive ARP replies (ping) in a local network

Possibilities I see:

Router (switch?) is misbehaving... can you try another one?
IP is duplicated, or Mask is incorrect... Check that the mask is the same and the IP different, but in same network.
Ultra rare case where there is a duplicate MAC... Check MAC on the two sysems.
ARP Cache problem... check your cache, like cat /proc/net/arp
ARP is malformed... check that the Address Resolution Protocol SHA SPA THA TPA are proper in your dump.

(perhaps post the ARP dump)


tn5250 won't install, needs libssl0.9.6 but libssl0.9.8 is installed

try

sudo apt-get remove libssl0.9.8
sudo apt-get install libssl0.9.6


How to make ubuntu as the second Operating System

You can edit the GRUB config file, but I recommend you use Grub Customizer:

https://launchpad.net/grub-customizer

sudo add-apt-repository ppa:danielrichter2007/grub-customizer
sudo apt-get update
sudo apt-get install grub-customizer

You can change the default build in the "General Settings" tab and set a timeout so you don't have to hit enter.  Use 0 if you don't want GRUB to display by default.

Secondly, if you want your entry to be in the first position you can move it up in the "List Configuration" tab.

If you would like to manually change the configuration file and not download this application then read this link

Just realize you must run "sudo update-grub" to apply any changes you make if you edit the configuration file which is not included in that link.


Empathy is telling me I have a new IM message but I can't find it

Had to restart the machine today and the phantom message went away.


Cannot connet to password protected wifis

Whatever this was, upgrading 12.04 -> 12.10 fixed the problem.


apt will use whatever repositories you have added to collect packages. If you limit this to Canonical ones, everything you get has been tested and in the majority of situations and setups, works well.

They will, for the most part, not be the bleeding edge that your software packages of choice have to offer.

They will be as stable and as secure as the people who curate those repositories can manage and will have as few compatibility and dependencies issues as humanly possible.

You can add numerous 3rd party repositories to apt. Doing so will update apt's view of available packages and versions but can start to break dependencies.

If an installed package A is dependent on installed package B, but package C needs an older or new version of package B, you will get an error when trying to install package C. Forcing it may break package A as well.

You can usually rectify most broken packages using apt or dpkg, which apt is effectively a wrapper for.

If you start installing packages from non apt based sources, be that their source code or pre-compiled binaries, you are at the mercy of their requirements. If they have dependencies you don't meet, you will need to manually install them. Possibly via apt, possibly not. Blindly following installation instructions can install things into your system which can overwrite apt sourced packages, or parts of them, effectively breaking anything that requires that package to be at a certain version. Alternatively they can be installed to your user only, so other user accounts will struggle to make use of them.

Ultimately you can do whatever you want and are comfortable with.

You can always start over if you break it, so keep the USB drive somewhere safe.


how to use ubuntu server virtualization feature?

Of course it is possible to run a virtual machine on a remote server without the need of installing a GUI there to control and manage the VM. You can even create a virtual machine on your Windows desktop to export it to the server, run it there, and use your Windows for display of the VM. However you will need a cross-platform solution that will run on both Windows, and Ubuntu.

In case you want to try out Virtual Box you will need the closed source (PUEL) but free version available from Oracle (see this question on how to install for Ubuntu and the user manual for installation on Windows) to get support for the Virtual Box remote desktop display feature.

There is a nice tutorial from the Virtual Box user manual on how to set this up and how to run virtual box in "headless" mode on a server to use a remote machine's display via VRDP.


AMD64 is basically a synonym for x86-64, x64, x86_64, and Intel 64. It is simply the the 64-bit version of the x86 instruction set.

The original specification was created by AMD and released in 2000, which is why people often use the AMD64 designation, as with the 64-bit ISO download of Ubuntu.


Shell tab-completion for service command broken as root

This is disabled by default on Ubuntu.

Read your /root/.bashrc:

# enable programmable completion features (you don't need to enable
# this, if it's already enabled in /etc/bash.bashrc and /etc/profile
# sources /etc/bash.bashrc).
#if [ -f /etc/bash_completion ] && ! shopt -oq posix; then
#    . /etc/bash_completion
#fi

Bash completion is all commented out. Apparently there's a reason for it I'm not aware of (recovery single user mode perhaps?).

The reason for why it does work when you do sudo su, sudo -s, sudo bash is that it doesn't really run login to make you completely root. When running sudo su - or sudo -i it really does completely logs you in as that user. Here, by example of the environment variable $HOME, more of this difference:

gert@gert-laptop:~$ id
uid=1000(gert) gid=1000(gert) groups=1000(gert),4(adm),7(lp),24(cdrom),27(sudo),[...]
gert@gert-laptop:~$ echo $HOME
/home/gert
gert@gert-laptop:~$ sudo -s
root@gert-laptop:~# id
uid=0(root) gid=0(root) groups=0(root)
root@gert-laptop:~# echo $HOME
/home/gert
root@gert-laptop:~# exit
gert@gert-laptop:~$ sudo su -
root@gert-laptop:~# id
uid=0(root) gid=0(root) groups=0(root)
root@gert-laptop:~# echo $HOME
/root


How to check bluetooth status via terminal

In addition to checking for the service you can use the command

hcitool dev

that will return all devices turned on.


12.04 LTS wireless not working in Dell Insprion E1405

Try connect other way: with android phone or LAN cable. Then go to System settings -> Additional driver. Check drivers and install what will offered.


How To Connect to Wireless Network in Lubuntu?

Try this.  Install Network Manager.  To do that, just press Ctrl+Alt+T on your keyboard to open Terminal. When it opens, run the command(s) below:

sudo apt-get install network-manager-gnome

Once done, you can setup the wireless network. type the following command to start the manager:

nm-applet


How to restore Ubuntu Server to default configurations without re-installing the whole system

WARNINGS

Please use with caution and backup your system! Tested on Lubuntu and should work on Ubuntu.

When offered the option to delete GRUB, select No or this will render your OS unbootable!

Requirements include:

ISO image of your OS

Steps:

Mount your ISO so you can access these files:

casper/filesystem.manifest
casper/filesystem.manifest-remove

Combine the two files

Don't run this command in the mounted iso folder, create a folder to keep these files

comm -3 <(cat filesystem.manifest | awk '{print $1}' | sort) <(cat filesystem.manifest-remove | sort) > default.txt

Get software currently installed on your system:

dpkg --get-selections | awk '{print $1}' | sort > currently_installed.txt

Compare what we got from the casper files and what we got from step 3 we get added software(s):

diff -u default.txt currently_installed.txt | grep "^+[^+]" | cut -c 2- > additions.txt

And to get what was removed:

diff -u default.txt currently_installed.txt | grep "^-[^-]" | cut -c 2- > removed.txt

Now to remove all added software(s):

sudo apt-get purge $(cat additions.txt)

And to add any removed software(s):

sudo apt-get install $(cat removed.txt)

Remove configuration files:

rm -rf .gnome .gnome2 .gconf .gconfd .metacity

NOTE:

You could always create an image of the system at install to reuse later (assuming your installing new), or
Re-install fresh, and
The files paths are assumed to be in the folder you created earlier, but if not then adjust your paths accordingly.
When offered the option to delete GRUB, select NO.

Source for further information:

http://www.kingletas.com/2012/07/restore-ubuntu-to-the-default-settings-without-re-installing-it.html


Help figuring out what's taking up disk space

OK. Mystery solved. Kind of. After futzing around, I decided to dismount my veracrypt volume (which is on one of the 4TB drives) and suddenly a 75 GB file showed up on the SSD drive. I have no idea why this does not show up when the veracrypt partition is mounted, nor do I know why it's on this particular drive (there are other things that I have on veracrypt partition that are not on the SSD), but I suppose this is more a question for truecrypt.  Anyway, all help was greatly appreciated.