Added wrong path to $PATH variable but can't find old varaible to delete it

PATH is usually set up in ${HOME}/.bashrc, the file yousource`d. To see which line, you could type:

grep -n virtualenvwrapper ${HOME}/.bashrc

Redo the step of the "tutorial for this on Ubuntu" (no actual link, and why should I go read it anyhow?) that had you entering the PATH, or edit ${HOME}/.bashrc yourself.


Pairing bluetooth input device does not work

I figured it out! (this is written with the bluetooth keyboard)

press the pairing-button on the backside of the keyboard
Do a search within your bluetooth devices (blueman gui)
right-click on the keyboard (also in blueman gui) -> pairing
type in 4 numbers with your USB keyboard and press enter
type in the same numbers with your bluetooth keyboard and press enter

This should pair the keyboard. After this you have to connect the keyboard service

right-click on the keyboard (also in blueman gui) -> settings
connect the service!

Finally you should have your keyboard working!


How to reassign Workspace Switcher keyboard shortcut?

There appear to be many solutions.

The one I chose that worked was to install CompizConfig Settings Manager, search for "Expo", then the first option on the right allows you to customize the key.


adb unable to see android device in bootloader mode here's the lsusb verbose information how do I install this?

When in download mode. Try using
fastboot devices and see if that recognises your device.


Can't paste text into Google Docs in Firefox

Just to note, for me such a problem was caused/solved by the privacy setting dom.event.clipboardevents.enabled.

When I opened Firefox about:config and set dom.event.clipboardevents.enabled to true, the Google Docs clipboard functionality started working.


Accidentally deleted my /etc directory, now unable to SSH into my VPS

Your system is broken.  You'll only be able to access it is if your VPS provider provides an out-of-band method to access it such as a virtual console - many VPS providers do provide this.

However in this case it's not likely to even meaningfully boot or do much without /etc, so you'll probably need to restore from a recent snapshot (easiest) or if you don't have a snapshot, you'll have to do a fresh image and then start restoring what you need from whatever backup you have.


Your install is UEFI.

It looks like you ran the 'buggy' UEFI in Boot-Repair. That is only required if you have a system that only boots Windows from UEFI menu.

To undo & to rename files to their original names, you just need to tick the "Restore EFI backups" option of Boot-Repair.

Also it looks like the only boot entry that will work currently is:

Windows UEFI bkpbootmgfw.efi

That is the renamed file that Boot-Repair renamed. If you undo the rename it will be without the bkp at beginning.

Boot-Repair also adds all the efi files that HP added as boot options. If you do not want those you have to edit 25_custom.

sudo cp -a /etc/grub.d/25_custom /etc/grub.d/bkup25_custom
gksudo gedit /etc/grub.d/25_custom
sudo update-grub

It also looks like os-prober is writing BIOS type entries that will not work.


To see the current configuration, open Deja Dup, go to "Folders to save" and "Folders to ignore".

You can also get this info from terminal using these commands:

gsettings get org.gnome.DejaDup include-list
gsettings get org.gnome.DejaDup exclude-list

I would recommend just to backup your home folder, and exclude less important folders like .cache, .dbus, and .gvfs. (I can find you more info on exclusions if needed.)

I'm not sure if it can backup the whole directory tree, but anyway there isn't any reason I can think of that a home user would need to do that. If you give more details about what you want to do, we can better answer the question.


Can't install Ubuntu, the 'Install' home screen is a white box

Try the alternative installer HERE.  This works for me for whenever I have a really old computer that will not run the regular installer.


Auto starting a program before any other program and preventing it to run the other programs until a directory is mounted

If you can use it, ncpfs is a filesystem module which allows you to mount a NetWare share using the Linux standard mount utility. This would allow you to add a line to your /etc/fstab which will mount the share as part of the system startup. You would then simply check to see if your mountpoint contains files to make sure that the mount worked successfully. Check with the Ubuntu documentation for detailed information on adding a line to /etc/fstab.

If you need to use ncpmount, bear in mind you will have to use the -P option, as the user will not be able to enter a password if one is required. That being said, you could use a rc.local file to run ncpmount as part of the system startup. I recommend looking to the Ubuntu documentation for detailed information about rc.local.

Finally, after doing all that typing, I found this document on Novell's site. It's a walkthrough for setting up /etc/fstab to automatically mount a NetWare share on system startup. That may be all the guide you need.

Sorry, I had prepared more helpful links for you, but I don't have enough reputation to post more than one.


How to delete inet6 Link address automatically?

You can't, that's how IPv6 works. (However, you can disable IPv6. See below.)

Explanation:

IPv6 doesn't use ARP to find which MAC address belongs to which IP, it uses the Neighbor Discovery Protocol. As a core concept, the NDP works over IP, not over Ethernet frames, so it needs an IP address to communicate. That's the "fe80" link-local address.

Solution:

If you don't want to use IPv6 at all, I suggest you blacklist the IPv6 module in the Linux kernel by adding the following line to /etc/modprobe.d/blacklist.conf:

blacklist ipv6

After a restart all your IPv6 addresses should be gone.

However, if you do plan on using IPv6, I suggest you seriously read up on it, otherwise you will be in a world of pain and security issues.


In MAAS 1.9.1, what do I do to fix the error "Node must be connected to a network"?

Visit the node details page for the node that is reporting "Node must be connected to a network".

On that page select the subnet you want the interface to DHCP from and then select "DHCP" in the IP assignment section.

Screenshot of networking Section with DHCP set on interface.


Recursively move all TXT files in subdirectories to other directories based on filename

You can use find command to find and copy all the files that founded.
The syntax is find <PATH-OF-THE-FILES-TO-COPY> -iname <NAME> -exec cp {} <PATH-COPY-THE-FILES-TO> \;

an example for command find /home/xthudrsdayx/Office/ -iname *.txt -exec cp {} /home/xthudrsdayx/txt/ \;

Remarks:

-exec cp is to exec the cp command on all the files that founded.
Asterisk (*) means any combination of ASCHII in the place you putted the *.
you can use many more filters of find command atman find.

Hope that was what you were looking for, if something not working or not understood please comment so we can try solve it together.


List of bought applications in Ubuntu Software Center or login.ubuntu.com

well the same idea was posted http://brainstorm.ubuntu.com/idea/29810/

Well as you can see in the link the idea was closed as rated as a bug. So it is a bug

il try to find the bug report.


Gedit error for non sudo - undefined symbol: cairo_surface_set_device_scale (undefined symbol: cairo_surface_set_device_scale)

I met this problem, when I add /home/silva/anaconda/lib to LD_LIBARY_PATH  before /usr/lib/x86_64-linux-gnu/ in ~/.bashrc. Many software failed to start after that.

I removed /home/silva/anaconda/lib, and source ~/.bashrc again, solved.


Errors while running Upgrade from the terminal. Can anyone help me analyse it?

The line "gzip: stdout: No space left on device" is the key to your problem: you're out of free space on that hard drive partition!

You can run "df" (disk free) command in terminal for fast check of free space on mounted partitions.


Looking at the specs, you have an Intel 3000HD chip?

If so, using

xgamma -gamma x.x

where x.x is the value should help you out. Setting x.x at 1.0 is the default, 1.2 should brighten things up a bit.

You can also spec the colour channels using

-rgamma -bgamma -ggamma

for red, blue and green respectively.


You can have charmstore at
GOPATH=/home/sajith/Projects/Backup/charm-store-server/charmstore
as you have written, however, then you need to change GOPATH for any other project.

I would recommend setting the GOPATH to:

mkdir /home/sajith/Projects/Backup/go
export GOPATH=/home/sajith/Projects/Backup/go
mkdir $GOPATH/src

Do the

go get -u -v -t github.com/juju/charmstore/...

The charmstore code is located in:

cd $GOPATH/src/github.com/juju/charmstore

Then execute:

make deps
make sysdeps
make install

Edit your question with new data to see if this helps.


Ok guys so I actually found a solution to my own problem :D

I updated the version of my Kernel to the newest available one that is on the Ubuntu website, then restarted the laptop and removed the nomodeset command. After that I booted my laptop and it recognized all the possible resolution there are. Hope this helps anyone with the same issue that I had.

turb0


So,
i made a Bios Update. Now OpenGL is detected and the CPU usage is normal.


The same issue on my laptop. After upgrading to 13.10 Hibernate option disappeared in Power Settings -> when the lid is closed.

Did as mentioned in https://bugs.launchpad.net/ubuntu-docs/+bug/1232814
I.e

In file /var/lib/polkit-1/localauthority/50-local.d/com.ubuntu.enable-hibernate.pkla

put this

[Re-enable hibernate by default in upower]
Identity=unix-user:*
Action=org.freedesktop.upower.hibernate
ResultActive=yes

[Re-enable hibernate by default in logind]
Identity=unix-user:*
Action=org.freedesktop.login1.hibernate
ResultActive=yes

After rebooting Hibernate menu reappeared in Menu. But still unavailable in Power Settings -> when the lid is closed


Cannot get my Brother printer to work after reinstalling Ubuntu Studio

Ok, I solved my self-induced problem; I replaced the toner and the printer works now. I had the toner light on and for some reason the machine was working ok under Windows but not Ubuntu. Go figure!!


Is it possible to use an Ubuntu Live CD and run GParted to partition a my HDD (including the partition that is usually mounted on a given system)?

Yes, you surely can..it is the easiest way to partition hard disks.
Here are instructions on how to do it with Ubuntu:

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

Please, note that, if you want to format, delete or resize a partition, the drive must be unmounted before doing it.


Requires installation of untrusted packages

Short version:

You need to update your "index of the repositories".

If you are using the GUI (graphical user interface; in this case, the "Update
Manager" window), then click the "Check" button first.  When it finishes, you
should then be able to click "Install Updates" and will experience no problems.
If you are using the command line, then execute command 1 before your usual
command 2:

sudo apt-get update
sudo apt-get upgrade

Long version:

The long version requires an understanding of the repository methodology.  In short, as compared to the historical method on Windows or Mac, where you go to various websites, download the piece of software you want, and install it, most Linux distributions (Ubuntu included) rely on a repository.  The repository is a community resource administered by maintainers that is basically a huge source of available software for your machine.  The upside is that installing software from the repository ensures that you do not install rogue software (i.e., malware), and that all software on your machine stays automatically up-to-date.

Whenever the community repositories update a package, they also update meta information about the package (the version number, basically).  The meta information includes a digital signature that ensures that when you download the update, that you downloaded the correct update, and that it wasn't corrupted in transit.  The message you are receiving is basically saying that the package updates you would be downloading do not match what your copy of the repository indexes suggest they should be.  Nine times out of ten, this means that you need to grab an updated copy of the indexes.  Hence, sudo apt-get update is your friend.

For more information on "this repository thing," check out the Ubuntu wiki entry.


Boot into windows 7.once you got the desktop,click on restart not shutdown.After restarting,select ubuntu os in the grub.After ubuntu booted up,click on the windows 7 partition.
Now it will be mounted and you can see the files present in that windows  partition.


The easiest way to install STEAM on Ubuntu 16.04 Xenial Xerus is by using apt-get command to fetch steam installed directly from Ubuntu's multiverse repository:

sudo add-apt-repository multiverse && sudo apt-get update && sudo apt-get install steam

If this doesn't work:

sudo dpkg --add-architecture i386 && sudo apt-get update

sudo apt-get install wget gdebi libgl1-mesa-dri:i386 libgl1-mesa-glx:i386 libc6:i386

Download the installer:

wget http://media.steampowered.com/client/installer/steam.deb

Locate the installer at the download location and install steam using gdebi

Hope this helps.


Torgaurd will not start with Crontab at reboot

First of all, sudo doesn't work in crontabs.

Next, you need to specify the full path to the .ovpn file.

Instead of this:

TorGuard.Canada.ovpn

you need something like this instead:

/home/just_some_guy/Downloads/TorGuard.Canada.ovpn

However, I believe this is not the recommended way to do this. See related post.


How to connect to a Ubuntu PC remotely by SSH

Sure you can!
First ifconfig to get your IP address.

Then, to connect, you need to type in a terminal:

ssh username@address_ip

So, if for example your name is tommaso and your ip is 123.123.123.123 you need to type ssh tommaso@123.123.123.123.

It will ask you the user password, of course!

If you need graphical interfaces, add the -x option after ssh.

If it doesn't work, try to install openssh-server on the server side. Thus something like sudo apt-get install openssh-server.


Unexpected Error: Error renaming temporary file, Text File Busy

Check if some java processes are running:

# ps -A | grep java

If it's so, check if it's the NameNode or DataNode service:

# jps
16192 Jps
1 DataNode

In this case, just stop the process by ID and try to edit configuration again.


You should be able to open a browser and type localhost:631 This will access CUPS and then add the network printer via the Administration Tab. See http://www.liberiangeek.net/2010/06/install-network-printers-cups-ubuntu-10-04-lucid-lynx/ for a better understanding.


Why is stdin/stdout failing with gplay on ubuntu?

Thanks, Serg - it's a streaming  media player from Freescale Semiconductor. Here's a link to the PDF manual:

https://www.element14.com/community/servlet/JiveServlet/downloadBody/49378-102-1-259394/Freescale.Application_Note_1.pdf


You have loop devices that are taking forever to mount during boot. Try and see what is mounted as loopback devices by running mount after boot.
My bet is that these are snaps (you clearly have snapd installed) and in the event that you have no use for snaps, get rid of them by uninstalling them and uninstalling snapd. It improved boot time in my case.

dev-sda7.device is your root partition. 19 seconds means that your hard disk is slow to activate, and unless you get you a new hard disk, I don't think this can be fixed.

I know most people wouldn't dream of this let alone try it, but you might want to disable plymouth and see if boot time improves in your case.
This will remove the graphical boot screen and replace it with scrolling text.

Disable plymouth by editing /etc/default/grub.
Find the line GRUB_CMDLINE_LINUX_DEFAULT and remove "splash" so that the line now reads:

GRUB_CMDLINE_LINUX_DEFAULT="quiet video=SVIDEO-1:d"

[Remember to backup your grub file before modifying it. You might want to read this: Disable plymouth to improve boot time.


It is most likely a firmware or driver issue.  If it is working over USB 2.0, then at least you can still copy files.  To help diagnose the problem, have you tried the drive in Windows over USB 3.0?  If it fails there, then it is most likely:

The drive
The USB 3.0 port
The USB 3.0 controller


You can try to install extundelete via the software center. If that is not working you will need to recover the lost files the hard way, some call the process data carving. Basically you run a tool like foremost to search your whole disk for pattern of lost files. Have a look here https://help.ubuntu.com/community/DataRecovery


Ok, first of all Ubuntu is free (as freedom) and by now free (as beer). From the business page:

No hidden costs, no lock-in
Looking to escape the cycle of endless Windows upgrades? Now, there's a real alternative. No licence fees and no licence tracking overhead. With Ubuntu, you can scale your desktop infrastructure while keeping your cost down. You only pay for the level of support you need.
Download now for free ›

What this means, that the support should be supplied by yourself and the community around Ubuntu. Of course, if you have a emergency, don't expect fast response of the community, as we (the community) are all volunteers and not paid employee. That said, Canonical offers paid support for enterprises:

Buy professional support services
Canonical’s support engineers understand how important your IT systems are. Support with our systems management tool Landscape, is available to suit all levels of demand.

If this is what you are asking about then be my guest into contacting Canonical Ltd.
This site is not managed by Canonical Ltd. in any manner as you can read in our meta question:

Canonical gave permission for Stack Overflow to use the Ubuntu trademark and logo for Ask Ubuntu. A Canonical employee also assisted in the site's new design to help meet the Ubuntu Brand Guidlines.
Beyond that Canonical has made no public announcements relating to Ask Ubuntu. (So we must assume that the site is not officially endorsed by or related to Canonical).
(Note: There are Canonical employees that are members of the Ask Ubuntu community.)

That said, I hope you can get a idea where is what you are looking for.


I have to install the vim package everytime I reboot the system. Suggest me a way to permanently install vim in my ubuntu (usb)!

Try this link to set up a persistent usb so that it saves your settings and changes.

http://www.howtogeek.com/howto/14912/create-a-persistent-bootable-ubuntu-usb-flash-drive/


Installing dotnet-sdk-5.0 on ubuntu 20.10

Did you remember to run sudo apt update before trying to install? If so, let's confirm if the package is available in your Apt cache:

Open a Terminal (if one is not already open)

Check apt-cache for the dotnet-sdk packages:
$ sudo apt-cache dump | grep dotnet-sdk

You should get something that looks like this:
Package: dotnet-sdk-2.1
Package: dotnet-sdk-3.1
Package: dotnet-sdk-5.0

Install the package that you'd like:
$ sudo apt install dotnet-sdk-5.0

Which should then result in:
Reading package lists... Done
Building dependency tree
Reading state information... Done
The following additional packages will be installed:
  aspnetcore-runtime-5.0 aspnetcore-targeting-pack-5.0 dotnet-apphost-pack-5.0 dotnet-host dotnet-hostfxr-5.0 dotnet-runtime-5.0
  dotnet-runtime-deps-5.0 dotnet-targeting-pack-5.0 netstandard-targeting-pack-2.1
The following NEW packages will be installed
  aspnetcore-runtime-5.0 aspnetcore-targeting-pack-5.0 dotnet-apphost-pack-5.0 dotnet-host dotnet-hostfxr-5.0 dotnet-runtime-5.0
  dotnet-runtime-deps-5.0 dotnet-sdk-5.0 dotnet-targeting-pack-5.0 netstandard-targeting-pack-2.1
0 to upgrade, 10 to newly install, 0 to remove and 3 not to upgrade.
Need to get 91.9 MB of archives.
After this operation, 382 MB of additional disk space will be used.
Do you want to continue? [Y/n]

Hope this helps you identify why apt couldn't find the package on your system.


runit is an alternative process supervisor (a la Upstart, Systemd, supervisord, watchdog, etc, etc, etc). It's not a default-install package.

I suspect you had it installed because you have recently removed something that depends on it. The current 12.04 list is below:

$ apt-cache rdepends runit
runit
Reverse Depends:
  dropbear
  dropbear
  vblade-persist
  twoftpd-run
  twoftpd
 |tinydyndns
  socklog-run
  socklog
  roundup
 |qmail-run
  mailfront
  ipsvd
  git-daemon-run
  dropbear
  dnscache-run
  djbdns
  dbndns
  daemontools-run
  daemontools
  cereal
  bcron-run
  bcron


System Monitor
In System Monitor enable All Processes for a more complete look...

Or use the top command in the terminal.
Memory
In order to take the speed advantage of memory interleaving, memory DIMMs should always be configured in equal size/type DIMM pairs. With 4G, you should have either added another 4G DIMM, or replaced it with two 8G DIMMs.
Windows

boot into Windows
open the Power control panel
choose change what the power buttons do
choose change options that are unavailable
uncheck fast startup
close the Power control panel
open an administrative command prompt window
type powercfg /h off
type chkdsk /f c:
approve to run chkdsk at next reboot
type chkdsk /f x: (replacing "x" with drive letters of other visible NTFS partitions)
reboot into Windows to let chkdsk run on drive C:

Update #1:
From the comments... Turned off Secure Boot in the BIOS, and it's working fine now.


I pressed ctrl with - and now my terminal view become so small, how to recover?

To zoom in, just press the following keys: Ctrl+Shift++ (without the numeric keypad)

To recover your initial settings, press Ctrl+0 (without the numeric keypad)

Alternatively, you can use the gnome-terminal View menu to perform such operations:


Having trouble locating files that are filling up disk space

You can use find command to list 40 Largest files in a file system/directory

find /path -xdev -type f -size +10000c -ls | sort -nrk 7,7 | head -40

Du is also use full to verify and find large folders

du -x -sh /path


Someone had a very similar problem with indicator-weather recently at Ubuntu forums and their submitted log is nearly identical to yours. The simple advice on that forum was to try to complete the update with

sudo apt-get -f install

and if that didn't work remove indicator-weather and purge its configuration files with

sudo apt-get purge indicator-weather

and then simply run sudo apt-get update and reinstall it. There are no other error codes in the logs that would suggest any more complicated fixes are necessary and the purge of the configuration files should solve the issue as it did at the other forum.


You're confusing different things. There is a little bit of code in the MBR. The MBR is right at the beginning of your HDD and also stores other stuff like the partition table. However, the information which can be stored there is not enough to boot a modern computer, and the format of MBR doesn't allow for storing any more data there. The classical generic MBR only provides 446 Byte for this and the modern standard MBR even only 218 Byte. (There are others as well.)

This code then loads information from a partition. If you use grub, the information is loaded from a Linux partition, namely from [whatever partition]/boot/grub and takes up 6.9 MB on my machine. The code Windows puts into the MBR also needs to load more information information from a partition. It's a lot more information and Windows gives it its own partition. That's why you have a partition about 100 MB in size when your computer came with Windows.

So you need to install the bootloader to /dev/sda. The installation process then will take care of putting the data it can't store in the MBR into [whatever partition]/boot/grub. Don't install the bootloader to a partition.


Which drivers should I use on 16.04 with AMD HD 6490?

Note: All of this applies to AMD graphics cards that arent very new (including yours). Newer ones(1) have hybrid(2) amdgpu-pro drivers or open-source amdgpu drivers.

It seems that no, you will not be able to use proprietary (fglrx and catalyst) drivers on 16.04. Or if then you have to somehow roll back xorg version without breaking everything connected to it.
Using free/libre (radeon) drivers is practically the only option on 16.04
In my experience, i can play all of my Steam (and other) games with radeon drivers
It really depends on the games. I just ran some benchmarks(3) from openbenchmarking.org and it seems that i have a GPU performance loss of about a quarter to a half. Playing LoL via wine is still fine for me with ~40fps. Native War Thunder is unplayable with ~4fps. Civ5 gets laggy when im not using the strategic view.

Conclusion: I suggest trying out the open-source radeon drivers especially if you have 16.04 installed already. Maybe they will be enough for you. If not, you should roll back to 14.04 (previous LTS, supported until 2019) to continue using proprietary fglrx or catalyst drivers. The thing with open-source drivers is that they will get better and better over time.

(1) Listed here under "AMD Product Compatibility".

(2) Mostly open-source with some binary blobs. Explained a bit here.

(3) I have AMD Radeon HD7670M. My results are here. The one with radeon drivers is titled kde5+p+k+f+e_radeon. Not all of those benchmarks are GPU-related.


The Broadcom STA driver wl is incorrect for your device. Please get a temporary ethernet connection and do:

sudo apt-get remove --purge bcmwl-kernel-source
sudo apt-get install linux-firmware-nonfree

Reboot, detach the ethernet and your wireless should be working.


Can't play VCD and DVD in Ubuntu release 12.04 (Precise) 64-bit

You probably just miss some libraries for reading DVD. Ensure you have libdvdcss2, libdvdread4 and libdvdnav4 installed:

sudo apt-get install ubuntu-restricted-extras libdvdread4 libdvdnav4

Then run:

sudo /usr/share/doc/libdvdread4/install-css.sh

Reference: https://help.ubuntu.com/community/RestrictedFormats/PlayingDVDs


How can I remove a single temporary key mapping without resetting the entire keymap?

Try:

xmodmap -e "keycode 62 = Shift_R"

I used xmodmap -pke to see the list of current mappings, and look up Left-Shift. The right one follows from symmetry.


FTP issue - FTP open Character encoding issue

Edit the /etc/locale.gen file, uncommenting the languages that you want to have in the system

sudo vim /etc/locale.gen

Then generate the files of each language with

sudo locale-gen

And finally make sure that your user has the variables "locale" that you need to the .bash_profile file.
For example English US:

echo "export LANGUAGE = en_US.UTF-8
export LANG = en_US.UTF-8
export LC_ALL = en_US.UTF-8 ">> ~/.bash_profile


There are no packages for 15.04 in this ppa, but the ones for 14.04 (trusty) may work.

You can directly download a deb file from PPA.

Click View Package details and download a 32 or 64-bit deb.

32-bit

64-bit


Setting up Ogre Game Engine in Ubuntu Desktop

To install Ogre-1.9 in Ubuntu 16.10, follow the steps given below :-

To install Ogre3D libraries and development tools, run the commands given below(one-by-one) from terminal :-

sudo apt-get update

sudo apt-get install libogre-1.9-dev
Then follow this tutorial of Setting Up An Application - Linux on Ogre Wiki


Ubuntu 14.04 Lightdm: Changing exec line in ubuntu.desktop breaks top menu bar after login

I wasn't able to determine the root cause, but I found a workaround that achieves the same result.

I just added the pop up banner script to /etc/profile.d/.


Prerequisities to installing OpenLDAP on a clean Ubuntu 11.10 Server install

you can follow this guide from the ubuntu server team :

https://help.ubuntu.com/11.10/serverguide/C/openldap-server.html


Is it safe to delete a Swap Partition on a USB install?

Read below first!

Hi Ian,
yes you could delete Swap with a live stick, but I don't recommend this. This may cause issues, depending on what OS you are using.
There is a much nicer way to do that:
Fire up a terminal (ctrl + alt + t), then type

sudo swapoff /dev/hdb2

replace hdb2 with your swap partition directory. You can get the directory by typing

sudo fdisk -l

So now your swap should be disabled. Then just remove the swap entry from /etc/fstab.
You can do this by typing

sudo nano /etc/fstab

Then hit enter and remove the line which extends the swap informations.

REBOOT!

After that you can easily delete the swap partition with gparted or a partition application of your choice. But I recommend you to first let it be there.

STOP, BEFORE YOU DO ANYTHING MENTIONED ABOVE, READ THIS:
You are right, a swap partition produce much of traffic, but this might not make the OS slower.
Another possibility instead of deleting the swap is to customize it:
Fire up a terminal and run this:

sudo nano /etc/sysctl.conf

Then add this line:

vm.swappiness=10

This customizes the swap, when it should be used. As lower the swapiness is, as less swap will be used. 10 is already extreme less. So swap will only be used in the worst case when there is absolutely no more RAM available.

That's it!

Sources:

How can I turn off swap permanently?
Removing Swap Space


Give a programm an unconstrained amount of RAM

I'm not sure what you mean by "give it more RAM" exactly, as that's not how the system works. If the program is only using 3.4 GB of RAM, then that is all it needs to use. If it needs to use any more than that, it will try to use more. There is no need to try and force it to use more.

If it is a 32-bit application, it may not be able to use more.

Though, if it's using that much RAM, I would wonder why, as it really shouldn't need to.


First open terminal by holding ctrl + alt then click t. With Terminal open you are ready to begin.

Next, you will want to list your drives. You have a few options. I like fdisk but you could also run lsblk as it may be easier for you. You can skip down to lsblk as I explain this below too.

fdisk

fdisk -l

This will output a bunch of details about your hard drives. What you are looking for is /dev/sd* (* in this case, means any letter a-z. e.g. My primary drive is /dev/sda)

You will also want to look at the Device details for the drive to identify the partition on the drive that holds the OS. For me, this is /dev/sda1. (sda being the hard drive, sda1 with 1 being the partition of the drive that is my OS. You can tell this due to the size of the partition.)

Next you will want to see what is already mounted.

df -h

Will show you what is currently mounted. You are making sure that the drive you identified in the first step is not already listed in here (this would be /dev/sda1 as my example above) as mounted. If it is located in this list, you will see the mount point (where you need to go to access the drive) on the right side and there is nothing more to do other than to cd to that location to access your files.

lsblk

lsblk

This outputs a simple representation of your hard drive structure that is easier to understand than fdisk. You are still trying to identify the hard drive location /dev/sda and the OS partition /dev/sda1 as I explain in fdisk. You can see in this output if there is a mount point for the drive you are looking for too; if so, there is nothing more to do other than to cd to that location to access your files.

Mounting the Drive

If you do not see the drive listed as mounted, you will want to mount it.

To mount the drive you need to first prepare a location to mount it. I like to use /mnt/Windows so let's create that mount point.

sudo mkdir /mnt/Windows

Now that the mount point is created, to mount the drive to it you run: (Note that I am using /dev/sda1 as /dev/sda is the drive I wanted to mount and the partition on the mount is 1 for my case; if yours is different you will want to use that letter you got from step 1)

sudo mount /dev/sda1 /mnt/Windows

Now you should be able to see the files by running ls

ls -la /mnt/Windows


I found the problem. There was a line in /etc/rc.local that added the rule on boot.


Ok Mystery is over: I changed my DVI cable to a vga cable with a vga to DVI adapter and suddenly, Ubuntu is able to recognize my monitor and set the correct resolution. Maybe this is that way because my monitor is pretty old. This is in no way a correct answer to the larger problem i.e. the inability to set the correct resolution through xrandr but I will live with it.


Creating a KVM on Ubuntu 14.04 host fails

Firstly, timing a command via time doesn't mean that its effects are undone after the command. So

time uvt-kvm create secondtest release=trusty

creates secondtest, and then you try to create it again:

uvt-kvm create secondtest release=trusty

which obviously fails, since the domain (and its associated image) already exists.

In the third command, you made a typo: secondttest instead of secondtest. So it should be:

uvt-kvm wait secondtest --insecure


Ubuntu One for Android without Google play

You can use F-droid. An Open Source alternative for Google Play:

F-DROID

On App just search for Ubuntu or Ubuntu One. But unfortunately i could not find Ubuntu One Music on it.


After countless hours I've finally found the problem.  It turns out I changed the version of gcc in order to install something a while back and that was causing the error.  All I did to fix it was

cd /usr/bin
sudo rm gcc
sudo ln -s gcc-4.8 gcc

Remake everything, and then adding the ndiswrapper module worked!


HL-1110 XML Paper Brother printer does not install on Ubuntu 14.04

Mine works well on ubuntu 14.04. I donwload the driver from Brother' site. Is a bash script than ask for the model of the printer and then install some packages.


Unable to mount windows share under vmplayer 12

Using that source:
https://communities.vmware.com/message/2510025#2510025

I composed joined command:

sudo apt-get remove open-vm-tools; sudo apt-get update; sudo apt-get install git; sudo git clone https://github.com/rasa/vmware-tools-patches.git; cd vmware-tools-patches; sudo ./download-tools.sh; sudo ./untar-and-patch.sh; sudo ./compile.sh

After that you will see shared folder.
Keep in mind, at the time of command executing, dozen of vmware tools different versions are download and installed and it takes around 1 hour.


Dual Boot Win8.1-Ubuntu 14.04 - Cannot load Win8.1 after reinstalling Ubuntu

After barely restrainin myself from throwing the PC out of the window, I created an empty partition and installed Windows in it.

So you had an EFI installation of Windows at/after this point? If your answer is yes, then that was good, and we can start troubleshooting from here.

  After the installation, the system booted Windows by default (no GRUB screen), which I guess is normal.....

Good. Yes, that is how it should be.

  I loaded Ubuntu from the BIOS, and I used Boot Repair to solve it. It gave me this error

Start again at installing Windows (alternative: reinstall the Windows bootloader with bcdboot), but this time don't use boot-repair. It generated another issue that we don't want in this situation (replacing what the default setup of GRUB thinks is the Windows bootloader file, which boot-repair unfortunately modified), instead we want the initial problem solved.

What is your actual problem with installing and booting Ubuntu on this computer alongside Windows?

I was able to boot Ubuntu on every UEFI-capable machine I got my hands on so far without additional tools. (I'm not bragging here.) It just comes down to understanding the boot behavior of the firmware in your computer and running grub-install with the right parameters, not modifying the Windows' boot setup. Some firmwares only allow to boot from the default bootloader, in that case try the answer from  Is it still possible to install Ubuntu to an external harddrive with UEFI?


In more or less open networks like a university wifi it is not uncommon to use client isolation so devices on the wifi cannot connect to each other. This is a security measure. This means that you may very well be just out of luck. Sorry.

To verify if this is your problem, you could try to ping the devices or try to connect to another computer of a friend with a known to work protocol (e.g. HTTP if one of the computers has a web server running).

If this doesn't work KDE connect probably won't work either.


Recording the radio streaming of Radiotray or Rhythmbox

Rhythmbox plugin

Yes - its certainly possible in 12.04.

I've been porting a few rhythmbox v0.x plugins to work with rhythmbox v2.9x - for example v2.96 used in 12.04 Ubuntu.

One GTK3 port is Radio-Browser

It is packaged in my rhythmbox PPA (link) below.

Alternatively, you can clone the GitHub repository and install:

how-to

sudo apt-get install git streamripper gir1.2-gconf-2.0
git clone https://github.com/fossfreedom/radio-browser
cd radio-browser
./install.sh

Finally, launch Rhythmbox, activate the global menu (move your mouse to the top of the screen) - Edit - Plugins - Internet  Radio Station Browser

Issues with this on GitHub not AskUbuntu or Launchpad - thanks.

Linked Questions:

How do I install third-party rhythmbox plugins?
Record a programs output with PulseAudio


apt-get install php7.0-curl saved my time.


Is there any problem in installing ClamAV (or any antivirus) in Ubuntu with any antivirus installed in Windows?

Well, as far as I know, the answer is "NO". Basically, the two antiviruses have no influence one over the other. They are installed on two different OSs, each one of them on a different partition. It's like two dogs guarding two different gardens.

The main difference is that you can use your ClamAV Antivirus to scan Windows from inside Ubuntu. But even in this situation, the two antiviruses will not interfere.


Compiz in XFCE4- Ubuntu-17.04: Setup progress

I've got some answers now.

There are some known defects in Compiz and its interaction with xfce panels.  One problem is that dragging windows across workspaces does not work anymore, perhaps not even in Compiz with Unity.  Also, the Compiz Viewport terminology is not understandable to the XFCE4 panel.  There is a patch on Arch linux systems, a special package : xfce4-panel-compiz.  However, I've tried to apply same patch to Ubuntu's current xfce4-panel package and it fails with fuzz, so no joy to report.   There is an Ubuntu bug report related to this, as discussed at Can't drag windows to another workspace on Ubuntu 16.04
There are 2 vital elements in the Compiz configuration. To my surprise,  I had discovered this in 2015: (Compiz, Multi-Head, Workspace Backgrounds and Success: compiz wallpapers changed via python script), but forgot. Back then, I quit using Compiz because of the failure to interact well with the XFCE4 panel, which is still a problem, but there are 2 tips that make the experience much better.

In the current Compiz configurator, ccsm, chose "Preferences" on far left, and change these defaults:

Backend: GSettings Configuration Backend

Integration: Uncheck "Enable Integration into the desktop environment"

The backend issue affects user-written scripts to do chores like change the wallpapers.  In my experience, the gsettings config backend is much much better and more stable, the dbus backend used to work great (circa 2012), but now Gsettings is the way to go!.

Turning off integration, of course, may cause other problems I don't understand yet. It may cause complications in interaction with XFCE4 panel, for example. However, that does not seem to work anyway. It appears to me that the desktop integration emphasized in current Compiz is for the Ubuntu Unity environment, not for XFCE4.

The DBUS backend in Compiz is not workable. If you are going to write scripts to change backgrounds and such, it is much more like to succeed if you use gsettings rather than dbus.  I've written the background changer program both ways and in Compiz, there is a problem in re-assigning the image array through dbus but it is not failing in Gsettings.

So my Python scripts mentioned in the 2015 blog post still work if you change to the Gsettings backend.

I cannot get the Compiz cube or rotate cube features to work at all now, but the Desktop Wall works fine and I'm happy enough with that.  Wobbly windows is worth it.
Compiz generally has a panic attack if you suspend the computer on one monitor, and then go to another place with two monitors and try to resume a session.  The problem is that the system is "aware" of the fact that there are two monitors, but, at least in my Dell 5510, it does not use the 2 monitors. Instead, it tries to show both desktops on the one laptop monitor. The two displays fight with each other, causing some unhappiness.  The mouse is not useful here, but it is possible to use the keyboard to launch "arandr" and choose video settings.   After that, it works fine.

These are the Compiz modules I have turned on.

Composite
Gnome Compatability
OpenGL
Desktop Wall
Viewport Switcher
Animations
Fading Windows
Window Decoration
Wobbly Windows
JPEG
PNG
Compiz Library Toolbox
Regex Matching
Mouse position polling
Session Management
Wallpaper
Workarounds
Application switcher
Scale
Move Window
Resize Window
Place Windows

Conspicuously, note that DBUS is not turned on anymore.

Conclusion:

After a lot of fiddling around, I'd say Compiz does work and the only major limitation is that the XFCE panel workspace switcher does not work well with it.

I'm going to try harder to apply the Arch linux patches for XFCE4 panels.


how to install Lexmark MS310Series V2XL printer driver in Libre Office in Ubuntu

You find the drivers at this page
http://support.lexmark.com/index?linkSelected=node2%5Esubnode2&page=driversdownloads


Trouble installing Ubuntu 14.04 Asus Zenbook NX500J with Nvidia gtx850m

It seems that you install wrong drivers.

Run in terminal

sudo apt-get install nvidia-346 nvidia-prime

That will install the correct driver. But an attempt to install a driver from .run file could spoil everything. It is better to run that file again with --uninstall option.


Wired connection icon is displayed instead of Wifi icon - Ubuntu 16.04

This is caused by a bug in Network Manager.  It seems that when wlan0 is renamed using the new naming scheme it confuses Network Manager and Network Manager thinks you have another ethernet connection.

It can normally be fixed with
systemctl restart NetworkManager.service
The command will have to be done after a reboot or suspend until the fixes are released


ubuntu unicorn unfinished install hickup

The easiest way would be to just install again. If you see a reason not to do so, state it.


/etc% grep -lw 20 **/*(.)
…
laptop-mode/laptop-mode.conf
…
$ grep -w 20 laptop-mode/laptop-mode.conf
# Default is 2 hours on AC (NOLM_HD_IDLE_TIMEOUT_SECONDS=7200) and 20 seconds
LM_AC_HD_IDLE_TIMEOUT_SECONDS=20
LM_BATT_HD_IDLE_TIMEOUT_SECONDS=20

and for that matter

/etc% grep hdparm **/*(.)
…
laptop-mode/laptop-mode.conf:# hdparm
laptop-mode/laptop-mode.conf:# really SATA drives that only _look_ like SCSI drives, and will use hdparm
laptop-mode/laptop-mode.conf:# Idle timeout values. (hdparm -S)
laptop-mode/laptop-mode.conf:# Power management for HD (hdparm -B values)
laptop-mode/laptop-mode.conf:# Write cache settings for HD (hdparm -W values)

This setting comes from laptop-mode-tools. Here are the default settings in /etc/laptop-mode/laptop-mode.conf:

# Idle timeout values. (hdparm -S)
# Default is 2 hours on AC (NOLM_HD_IDLE_TIMEOUT_SECONDS=7200) and 20 seconds
# for battery and for AC with laptop mode on.
#
LM_AC_HD_IDLE_TIMEOUT_SECONDS=20
LM_BATT_HD_IDLE_TIMEOUT_SECONDS=20
NOLM_HD_IDLE_TIMEOUT_SECONDS=7200

I'm changing those 20s values to something sensible.


How can I maximally compress .gz files in Nautilus?

Simply run:

gconftool --type String --set /apps/file-roller/general/compression_level maximum

Other options for this setting: very_fast fast normal

Edit: This doesn't appear to be well implemented. I have compressed a text file (highly compressible) using a number of different formats using normal and maximum settings:

52167 client.h  # uncompressed

15980 client.h.normal.7z
15979 client.h.max.7z

15861 client.h.normal.bz2
15861 client.h.max.bz2

17034 client.h.normal.gz
17034 client.h.max.gz

15892 client.h.normal.lzma
15892 client.h.max.lzma

16641 client.h.normal.zip
16486 client.h.max.zip

zip was the only format that showed any real difference (still tiny on the scale of things).


Broken Package when trying to install libminiupnpc-dev

Best solution is, if those needed packages are in the Official Ubuntu Repository, remove that PPA and install needed packages.

It seems that the libminiupnpc-dev that going to be installed from the Main repository, not from the PPA. If you want to use that repository somehow, you have to do Pinning. That means you need gain a higher position to that PPA in installation. To do that run this:

gksudo gedit /etc/apt/preferences

Then add following lines to the Gedit and save:

Package: libminiupnpc-dev
Pin: release o=Ubuntu
Pin-Priority: 100

Package: libminiupnpc-dev
Pin: release o=LP-PPA-<ppa name>
Pin-Priority: 200

** Replace < ppa name > with that PPA name(without phrase ppa:)


Installing Ubuntu INSIDE Windows (via the Wubi installer) is not supported for Windows8.
See the warnings on the official WUbi page: http://www.ubuntu.com/download/desktop/windows-installer


how to install gdb and valgrind in ubuntu

try this first:

sudo apt-get install libc6-dbg gdb valgrind


Display and cursor are out of sync on Ubuntu 18.04 tablet

I had the same issue and did the following:

Find the display which should be rotated xrandr --query
Invert the screen (my screen is called eDP-1) xrandr --output eDP-1 --rotated inverted
Disable auto rotation of the screen gsettings set org.gnome.settings-daemon.plugins.orientation active false

If everything works fine just stop there. In my case I had to invert the cursor as well with the follwing commands:

Find all input devices xinput
Display the properties of your input device (my device was called "Virtual Core Pointer" with id=2) xinput list-props 2
Change the "Coordinate Transformation Matrix" with xinput set-prop 2 "Coordinate Transformation Matrix" -1 0 -1 0 -1 0 0 0 1

For my answer I combined the following articles:

Rotate screen

Disable auto screen rotation

Rotate input device


The product string can be mismatch with what it should be. I think its fine as long as string shows same product family. Hybrid cards indeed complicated stuff and when its about the play games at Steam, selecting right card can be so buggy. As an example Dota with Hybrid RADV didnt work with Mesa 17.2 and below, at least for me.

Well first try blacklist radeon module from kernel.
How to blacklist radeon module?

Try Oibaff's Mesa stacks, and if there no problem appear use them.

Install radeon-profile with its daemon. https://github.com/marazmista/radeon-profile
Its a usefull control center for your AMD card. Set Performance/High mode your card. You can OC too, as i always do.

Last use glxinfo | grep "OpenGL" for GLStrings, its more proper way yet produce same result.


How to configure ranger to open pdf files with Foxit Reader

This is not what aliases are designed for. Instead of filling in the alias in your config file, try filling in a real command. This is either the full path name to the executable, or a symlink to it or a script that calls it. Let us go for a symlink.

If you want to launch FoxitReader without having to type in the full path name, create a symlink to the FoxitReader executable in a folder that is in your PATH. In Ubuntu, a folder ~/bin (a folder called bin in your home folder) automatically will be added to your path if it exists. So if you do not yet have a bin folder in your home folder, then create one:

mkdir ~/bin

Then create a symlink to your executable into that folder:

ln -s  /home/username/opt/foxitsoftware/foxitreader/FoxitReader ~/bin/foxitreader

Now you can launch FoxitReader simply by typing the command foxitreader. In addition, your rifle.conf config file should now work.


Where can I browse the package database using a web-browser

The direct equivalent of the site is:

http://packages.ubuntu.com

  This site provides you with information about all the packages available in the Ubuntu Package archive.


How to deploy Juju charm in development branch

Assuming you're dir structure looks like:

/home/foo/charms/trusty/quantum-gateway

and you are in /home/foo/charms

You would deploy using:

juju deploy --repository=. local:trusty/quantum-gateway

Extra:

The distro version folder name trusty/ is important. If you are deploying a precise charm then you would need to have it named precise/. Another thing to note is that the folder name needs to match the name defined in the metadata.yaml file.


On one hand this answer is six years late, on the other hand it's a blink of the eye if the internet is eternal!
You can get the real uptime with this little bash script:

$ suspendtime

Apr 07 05:53:34 to Apr 07 17:07:17 suspended 11 hours, 13 minutes, 43 seconds
Apr 07 21:56:34 to Apr 08 04:20:57 suspended 6 hours, 24 minutes, 23 seconds
      (... SNIP ...)
May 08 05:55:20 to May 08 16:32:37 suspended 10 hours, 37 minutes, 17 seconds
May 08 23:21:00 to May 09 07:02:05 suspended 7 hours, 41 minutes, 5 seconds

Linux uptime 2,813,939 seconds (4 weeks, 4 days, 13 hours, 38 minutes, 59 seconds)
64 Suspends 1,715,196 seconds (2 weeks, 5 days, 20 hours, 26 minutes, 36 seconds)
Real uptime 1,098,743 seconds (1 week, 5 days, 17 hours, 12 minutes, 23 seconds)

Linux will report uptime as 8 days and 40 minutes. The real uptime (after subtracting suspend time) is about 2 days and 18 hours.

suspendtime bash script
Here's the code you can copy to your system:
#!/bin/bash

# NAME: suspendtime
# PATH: $HOME/askubuntu/
# DESC: For: https://askubuntu.com/questions/321855/how-to-get-real-uptime
# DATE: November 6, 2019.

# NOTE: Calculate suspend time from systemd's journalctl

# UPDT: 2019-11-07 Fine-tune removing 0 Units in DaysMinutesStr
#       2020-05-09 Add "weeks" unit measure to DaysMinutes() function

# Duplicate DaysMinutes from ~/.bashrc for Ask Ubuntu
DaysMinutes () {

    local w d h m s
    (( w = ${1} / 604800 ))
    (( d = ${1}%604800 / 86400 ))
    (( h = (${1}%86400) / 3600 ))
    (( m = (${1}%3600) / 60 ))
    (( s = ${1}%60 ))
    DaysMinutesStr="$w weeks, $d days, $h hours, $m minutes, $s seconds"

    # Convert 1's to singular
    [[ ${DaysMinutesStr:0:2} = "1 " ]] && \
        DaysMinutesStr="${DaysMinutesStr/weeks/week}"
    DaysMinutesStr="${DaysMinutesStr/ 1 days/ 1 day}"
    DaysMinutesStr="${DaysMinutesStr/ 1 hours/ 1 hour}"
    DaysMinutesStr="${DaysMinutesStr/ 1 minutes/ 1 minute}"
    DaysMinutesStr="${DaysMinutesStr/ 1 seconds/ 1 second}"

    # Suppress zero strings
    [[ ${DaysMinutesStr:0:1} = "0" ]] &&
        DaysMinutesStr="${DaysMinutesStr/0 weeks, / }"
    DaysMinutesStr="${DaysMinutesStr/ 0 days, / }"
    DaysMinutesStr="${DaysMinutesStr/ 0 hours, / }"
    DaysMinutesStr="${DaysMinutesStr/ 0 minutes, / }"
    DaysMinutesStr="${DaysMinutesStr/, 0 seconds/}"
} # DaysMinutes

# Build array of suspend cycles from Systemd
IFS=$'\n' Arr=( $(journalctl -b-0 | \
                grep -E 'systemd\[1]: Start.*Suspend' | cut -c1-15) )

[[ ${#Arr[@]} -gt 0 ]] && upper=$(( ${#Arr[@]} - 1 ))
[[ $upper -gt 0 ]] && for (( i=0; i<upper; i=i+2 )) ; do
    (( SuspendCount++ ))
    Time=$(( $(date +%s -d "${Arr[i+1]}") - $(date +%s -d "${Arr[i]}") ))
    SuspendTime=$(( SuspendTime + Time ))
    DaysMinutes "$Time"
    printf "%s to %s suspended%s\n" "${Arr[i]}" "${Arr[i+1]}" \
          "$DaysMinutesStr"
done

echo
LinuxTime=$(( $(date +%s -d "Now") - $(date +%s -d "$(uptime -s)") ))
DaysMinutes "$LinuxTime"
printf "Linux uptime %'d seconds (%s)\n" "$LinuxTime" "$DaysMinutesStr"
DaysMinutes "$SuspendTime"
printf "%s Suspends %'d seconds (%s)\n" \
        "$SuspendCount" "$SuspendTime" "$DaysMinutesStr"
RealTime=$(( LinuxTime - SuspendTime ))
DaysMinutes "$RealTime"
printf "Real uptime %'d seconds (%s)\n" "$RealTime" "$DaysMinutesStr"

About half the program is converting seconds to human readable format in weeks, days, hours, minutes and seconds. The function DaysMinutes does this and was copied from my ~/.bashrc file where you may want to put that function yourself.

How it works
The key component is getting suspend start and end times from journalctl:
$ journalctl -b-0 | grep -E 'systemd\[1]: Start.*Suspend'
Oct 31 05:55:19 alien systemd[1]: Starting Suspend...
Oct 31 16:54:26 alien systemd[1]: Started Suspend.
 (... SNIP ...)
Nov 07 21:07:28 alien systemd[1]: Starting Suspend...
Nov 08 05:08:52 alien systemd[1]: Started Suspend.

The journalctl -b-0 command reads all the system messages for the current boot. You could enhance the function to look at the previous boot using -b-1 the boot before that with -b-2, etc.
The grep command with regex does the heavy lifting returning 32 system messages pertaining to suspend from the 19,330 system messages recorded (on my system)


Do I need a dedicated graphic card for ubuntu?

Ubuntu is working very well with integrated Intel graphic card. The answer is no, you definitely don't need to choose a laptop with a dedicated graphic card.


How to check if Unity web apps for gmail (or other) is installed?

If you choose command-line method than @SylvainPineau 's answer is ok.

Otherwise you can find-out (or launch) directly from Dash as following!

For gmail notification:

For configuring manually unity-webapps, goto userscript /usr/share/unity-webapps/userscripts/unity-webapps-gmail. more


The conventional way is to install using dpkg. It is a new feature of apt to install from deb files. That's why the correct syntax is not always clear. man apt doesn't tell much either.

So a guaranteed way is to copy the deb file to your Home directory and running

sudo dpkg -i google-chrome-stable_current_amd64.deb

If it is the first time you install Chrome, you will get some error messages regarding missing dependencies. You can fix it by

sudo apt install -f

Instead of copying to Home you can use the path

sudo dpkg -i ~/Downloads/google-chrome-stable_current_amd64.deb

Update: It looks like the solution is easier. OP made a typo in the command. The file name is wrong amd.64.deb :-)

So it is likely that the initial command with the correct file will work as well.


Where can I find snapd update or refresh logs? How does snapd inform the user about updates?

snap changes will let you know what changed.

e.g.

alan@gort:~$ snap changes
ID    Status  Spawn                 Ready                 Summary
1289  Done    2017-05-30T08:39:03Z  2017-05-30T08:39:14Z  Auto-refresh snap "syncthing"


Download the regular 32-bit Kubuntu ISO (the recommended download) from the official Kubuntu download page.

Instructions on creating a Live USB can be found on the above-linked site, and are reproduced below, for your installation-media-creating pleasure!

  Burning a CD or creating an install USB stick

  Kubuntu can be installed from a recordable CD (or DVD) or from an USB stick. Then it can be used as a regular operation system, or as a Live image which you can install Kubuntu from. For more information, see Burning ISO Howto and Installation From USB Stick from the Ubuntu Community Documentation website.

Personally, I prefer using LiLi to create bootable USBs. I've always had more success with that than with Unetbootin or anything else.

It's really simple to use, and you can't go wrong.

Now, to setup your BIOS to boot up from your USB key, follow these steps, taken from here.

  Boot with the USB flash frive connected, and enter the BIOS setup.
  Navigate to the Boot order screen, which may look similar to the one below.

  Hard drive, floppy drive, and optical drive will be listed on this screen, and the listed order of them is the boot order of your
  computer.
  Choose Hard Drive if you want to set the computer to boot from your USB drive, as it is probably detected by your BIOS as a hard disk, not a removable drive..
  Change the boot order of the hard drives. Choose Hard Drive first and then move your USB flash drive up in the list to make sure it's first. The boot order can usually be changed with the + and - keys.

  >

  Finally, save the changes to the BIOS setup by locating and choosing the
  Exit Saving Changes (or similarly worded) option. This can usually be accomplished by hitting F10.

Reboot your computer once it has been set up to boot from your USB flash drive, and you should be good to go! You'll be well on your way to installing your favorite Linux distribution.


Welcome to the wonderful world of UEFI:

You've installed Windows 10 in UEFI mode
You've installed Lubuntu in BIOS mode

So the options are:

Reinstall lubuntu in UEFI mode
go to the UEFI firmware and choose BIOS boot mode and boot off HD2 to boot lubuntu.


I experienced the same problem. I found out that my gcc-4.6.3 somewhat miscompiles it. After upgrading to gcc-4.7 and recompiling gmp-5.0.5, I was able to install mpfr-3.1.1 smoothly (make check passes).


Here is the script that I threw together for use with @fossfreedom's answer. It uses GIO to interface to GVFS and Tkinter for the GUI, and is written in Python 2.7. It supports multi-line annotations. The GUI looks like this:

prerequisites
You need to install tkinter:

sudo apt-get install python-tk

to use

Save the code as a file using your favourite editor in a known folder location - for example /home/[home-folder-name]/scripts/notesscript

Then - if you are using naultilus-actions, use a command:

python /home/[home-folder-name]/scripts/notesscript

The code:

import gio
class GVFSNotes:
    ATTRIBUTE_KEY = 'metadata::annotation'
    def __init__(self, f):
        self.__f = f
    def _get_attribute(self, key):
        return self.__f.query_info(key).get_attribute_string(key)
    def _make_setter(self, key, val):
        info = gio.FileInfo()
        info.set_attribute_string(key, val)
        return info
    def _set_attribute(self, key, val):
        self.__f.set_attributes_from_info(self._make_setter(key, val))
    def get(self):
        return self._get_attribute(self.ATTRIBUTE_KEY)
    def set(self, val):
        self._set_attribute(self.ATTRIBUTE_KEY, val)
import Tkinter as tk
class Dialog:
    def __init__(self, title, initial):
        self.root = tk.Tk()
        self.text = None
        self._mkGUI(title, initial)
    def settext(self):
        self.text = self.entry.get(1.0, tk.END).rstrip()
    def onCancel(self):
        self.root.destroy()
    def onOkay(self):
        self.settext()
        self.root.destroy()
    def _mkButtons(self):
        (tk.Button(self.root, text="Cancel", width=10, command=self.onCancel)
            .pack(side=tk.LEFT)
        )
        (tk.Button(self.root, text="Okay", width=10, command=self.onOkay)
            .pack(side=tk.RIGHT)
        )
    def _mkEntry(self, initial):
        self.entry = tk.Text(self.root, width=60)
        if initial != '' and initial != None:
            self.entry.insert(tk.END, initial)
        self.entry.pack(fill=tk.X, expand=True)
        self.entry.focus_set()
    def _setTitle(self, title):
        self.root.wm_title(title)
    def _mkGUI(self, title, initial):
        self._mkEntry(initial)
        self._mkButtons()
        self._setTitle(title)
    def show(self):
        self.root.mainloop()
        return self.text
def main(path):
    notes = GVFSNotes(gio.File(path))
    oldtext = notes.get()
    newtext = Dialog('Notes for ' + path, oldtext).show()
    if newtext != None and newtext != oldtext:
        notes.set(newtext)
if __name__ == '__main__':
    import sys
    main(sys.argv[1])


Ubuntu 16 LTS Connection to wifi suddenly extremely slow (Wireless 7260)

The latest firmware package contains the -17 firmware; your device loads -16. Let's try installing it:

wget http://mirrors.kernel.org/ubuntu/pool/main/l/linux-firmware/linux-firmware_1.161_all.deb
sudo dpkg -i linux*.deb

Next, check the settings in the router. WPA2-AES is preferred; not any WPA and WPA2 mixed mode and certainly not TKIP. Second, if your router is capable of N speeds, you may have better connectivity with a channel width of 20 MHz in the 2.4 GHz band instead of automatic 20/40 MHz, although it is likely to affect N speeds. I also have better luck with a fixed channel, either 1, 6 or 11, rather than automatic channel selection. Also, be certain the router is not set to use N speeds only; auto B, G and N is preferred. After making these changes, reboot the router.

Next, I recommend that your regulatory domain be set explicitly. Check yours:

sudo iw reg get

If you get 00, that is a one-size-maybe-fits-all setting. Find yours here: http://en.wikipedia.org/wiki/ISO_3166-1_alpha-2 Then set it temporarily:

sudo iw reg set IS

Of course, substitute your country code if not Iceland. Set it permanently:

gksudo gedit /etc/default/crda

Use nano or kate or leafpad if you don't have the text editor gedit.

Change the last line to read:

REGDOMAIN=IS

Proofread carefully, save and close the text editor.

Next, I'd set IPv6 to Ignore in Network Manager: http://docs.fedoraproject.org/en-US/Fedora/18/html/Installation_Guide/images/netconfig/network-connections-ipv6-ignore.png  This example is for ethernet, but you want wireless.

Reboot and tell us if the connectivity is improved.

You might also try a couple of driver parameters:

sudo -i
echo "options iwlwifi swcrypto=1 11n_disable=8"  >>  /etc/modprobe.d/iwlwifi.conf
exit

Reboot. Can you connect?


Encrypt second hard disk with same password

You should have the tool cryptsetup already installed.

To show details of the current cipher you can run the following command:

sudo cryptsetup status sda5_crypt

Replacing sda5_crypt with the name of your encrypted volume.
You should see an output similar to this:

  type:    LUKS1
  cipher:  aes-xts-plain64
  keysize: 512 bits
  device:  /dev/sda5
  offset:  4096 sectors
  size:    482697216 sectors
  mode:    read/write
  flags:   discards


For a graphical package manager, you can try Synaptic Package Manager. It's much faster than USC. Write this in terminal:

sudo apt-get update && sudo apt-get upgrade

sudo apt-get install synaptic

Another suggestion: apt is great and extremely fast, just give a try to apt-fast.

sudo add-apt-repository ppa:apt-fast/stable

sudo apt-get update

sudo apt-get install apt-fast

You will have a much faster download experience with apt-fast.
More here: http://www.webupd8.org/2012/10/speed-up-apt-get-downloads-with-apt.html


How do I restore previous packages after a failed update?

In /var/cache/apt/archives, there should be .deb files from previous upgrades.  You should be able to use these to downgrade using dpkg.

If you know what packages you want to downgrade, simply locate the oldest/previous version .deb of the program, and type sudo dpkg -i <name of .deb here> into a terminal. It might warn you about downgrading - just type y.

Since you don't know which packages got upgraded, and there could potentially be many packages that need to be downgraded, you could copy a single version of each program in the archives folder to a separate folder, and then run sudo dpkg -i *.deb while in the folder.

Once everything's downgrading correctly, just upgrade again!

Sources:

Downgrading from a broken wine version
Wine 1.5.20 Ubuntu 12.10 FUBAR woes...


On my Ubuntu 18.04, I solved it this way. There is no need to edit /etc/default/grub file.

Check that the integrated GPU is used by default by running glxheads

$ glxheads
   ...
   GL_VERSION:  3.0 Mesa 18.0.5
   GL_VENDOR:   Intel Open Source Technology Center
   GL_RENDERER: Mesa DRI Intel(R) Sandybridge Mobile

Check that the discrete GPU is visible but DynOff

$ sudo cat /sys/kernel/debug/vgaswitcheroo/switch
  0:DIS: :DynOff:0000:01:00.0
  1:IGD:+:Pwr:0000:00:02.0

Enable the discrete GPU for the glxheads and run it again. You can see that the renderer has changed.

$ DRI_PRIME=1 glxheads
  GL_VERSION:  3.0 Mesa 18.0.5
  GL_VENDOR:   X.Org
  GL_RENDERER: AMD TURKS (DRM 2.50.0 / 4.15.0-32-generic, LLVM 6.0.0)

Additionally, while running DRI_PRIME=1 glxheads, in the different window check that now the discrete GPU is DynPwr instead of DynOff

$ sudo cat /sys/kernel/debug/vgaswitcheroo/switch
  0:DIS: :DynPwr:0000:01:00.0
  1:IGD:+:Pwr:0000:00:02.0

So you need to run each application with DRI_PRIME=1 in order to use discrete GPU. Also, you can set this environmental variable permanently  https://unix.stackexchange.com/questions/117467/how-to-permanently-set-environmental-variables


How to change default screen for touch/stylus when using a dual screen setup on a tablet?

For those who use a Dual Screen setup with touchscreen or stylus and face this issue, I found a solution.
https://networks.guru/2018/11/23/using-dual-monitor-dual-touch-screens-on-ubuntu/
It involves creating a script that will run on startup and will force the touch to focus on only the selected screen.
The script only works when booting up and the secondary screen is connected. If anybody knows how to modify the script to include running the script again if the secondary screen is disconnected and connected again that would be great help. When disconnecting and reconnecting a secondary screen through HDMI, the touch/stylus defaults back to both screens instead of one.


From the bash manual:

  Aliases are expanded when a function definition is read, not when the
  function is executed, because a function definition is itself a
  command.

I'd bet that your aliases are defined after these functions are defined. Try defining the functions later.

For reference, I tested foo () { ll "$1"; }, using the ll alias from the default .bashrc, and it worked fine.

Runnable example:

def-before() { do-foo; };
alias do-foo="echo foo u!"
def-after() { do-foo; };

def-before
# prints "do-foo: Could not find command"

def-after
# prints "foo u!"


Message of the day exited with return code 2

I have experienced that, too. What fixed it for me is by reverting to an earlier version of Twisted. The issue started occurring on Twisted version 21.2.0. I uninstalled that version by executing:
sudo pip uninstall twisted

Then, installed Twisted again, but this time using the version 20.3.0 by executing this:
sudo pip install twisted==20.3.0


How do I open all windows when clicking the icon in Ubuntu dock?

You can change the click-action on Ubuntu Dock icons. Open Terminal and run

gsettings set org.gnome.shell.extensions.dash-to-dock click-action 'minimize'

Now if you click on an application icon with multiple open windows, it will switch between minimising and restoring all windows.


Boot from the Ubuntu Live CD and open Terminal.

Run this command: sudo fdisk -l (to get the device name):

radu@Radu: ~ > sudo fdisk -l
[sudo] password for radu:

Disk /dev/sda: 250.1 GB, 250059350016 bytes
255 heads, 63 sectors/track, 30401 cylinders, total 488397168 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x004aa9ec

   Device Boot      Start         End      Blocks   Id  System
/dev/sda1   *        2048      718847      358400    7  HPFS/NTFS/exFAT
/dev/sda2          718848    61431807    30356480    7  HPFS/NTFS/exFAT
/dev/sda3        61432621   463410989   200989184+   f  W95 Ext'd (LBA)
/dev/sda4       463410990   488392064    12490537+  83  Linux
/dev/sda5        61432623   450826239   194696808+   7  HPFS/NTFS/exFAT
/dev/sda6       450828288   463409151     6290432   82  Linux swap / Solaris

In my case, my Ubuntu is on: /dev/sda4.

Run sudo fsck /dev/sda4 (you should change /dev/sda4 with your device where is installed Ubuntu). Restart the system and boot normally.

Sources: How to Fix an Ubuntu Error: "No init found. Try passing init= bootarg".

Another related answers you can find here: How can I repair grub? (How to get Ubuntu back after installing Windows?).


ThinkPad T410 volume buttons' indicators not working on Xubuntu

Found out the solution myself:
For the mic mute button:
 1. Open settings -> From "Hardware", select "Keyboard" -> "Application Shortcuts"
 2. Click on "Add"
 3. In Command, Type this: amixer set Capture toggle
 4. Click "OK" -> Press the mute button.
 5. Done. Now when pressed, the mic will be mute-ed, and the indicator LED also turns on.

For the trackpad disabling:
 Repeat the same steps, except, instead of amixer set Capture toggle as the command, use this guide to get the command: https://askubuntu.com/a/67724/511354, and of course, press the trackpad-disable combination instead of min-mute key


This worked for me (and it works to cross compile most other third-party software):

$ export PATH=$PATH:<path to directory containing your cross-compiler binaries>
$ cd <path to the directory containing the thirdparty code>
$ ./configure --prefix="<installation path>" --host=arm-unknown-linux-gnueabi

Add your CFLAGS and other configuration parameters to the configuration parameters. E.g.,

$ ./configure --prefix="<installation path>" --host=arm-unknown-linux-gnueabi -CFLAGS="-Os" --enable-threadsafe

If in your case the target system is specified by arm-none-linux-gnueabi, replace the host in the above example:

$ ./configure --prefix="<installation path>" --host=arm-none-linux-gnueabi -CFLAGS="-Os" --enable-threadsafe

The paths to GCC, CC, AR, ... will be found from the host you've set.


How do I have a headless machine share its wireless connection through ethernet?

Here's a whole article that demonstrates several different methods, including CLI only ones, to set up internet connection sharing.  Hope this helps, :-)

https://help.ubuntu.com/community/Internet/ConnectionSharing


It is, as can be expected, called ubuntu-gnome-desktop. I assume there is also a task with the same name.


This could be because the WI-FI router drops packets.
It happens when the size of the packets are to big.

try lowering your MTU size.

If your wifi interface name is wl0:

 sudo ifconfig wl0 mtu 1400

This setting is harmless and not persistent over reboot.
If it works and you accept the answer I will update with an explanation on why this happens :)


Run sudo ldconfig, it solves "curl: symbol lookup error: curl: undefined symbol: curl_url_cleanup"
From : https://mysiar.github.io/devops/2020/04/23/curl-from-src.html


There aren't any Linux alternatives that look exactly like Windows 8. However, there is an alternative that is styled similar to Windows 7 with a Windows 8-esque theme, named ZorinOS.

Personally, I would simply recommend trying out the different Ubuntu flavours. Kubuntu (KDE), GNOME Ubuntu (GNOME), and Ubuntu (Unity) are the main highlights.


How can I transfer Skype conversations from an old user profile to the new one?

In Skype 5.4.0.1, pull down the Tools menu, and select Export chat history from Skype 4.3.


Make a live flash drive, and install boot repair on it and follow the instructions.

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

sudo apt-get update

sudo apt-get install -y boot-repair

boot-repair

You can get more details at: https://www.howtogeek.com/114884/how-to-repair-grub2-when-ubuntu-wont-boot/


Which release should I use for an ACER Aspire 1640 laptop?

It seems your laptop will just barely meet the minimum recommended system requirements for regular Ubuntu, particularly with regards to the amount of RAM present.

You can always try making a LiveCD/LiveUSB of Ubuntu to try on your machine and see how it performs before doing an actual installation. Keep in mind the performance will be slightly lower than once it is actually installed, however. If you decide that Ubuntu's performance is not good enough for you on that machine, you may also want to take a look at Xubuntu and Lubuntu, both of which are officially-recognized derivatives which aim to have better performance on low-end systems.


I don't have permission to access the subdirectories of a mounted share I created

I found a way what worked for me! I changed the /etc/fstab to:

//servername/sharename /media/sharename cifs credentials=/home/ubuntuusername/.smbcredentials,rw,nounix,iocharset=utf8,file_mode=0777,dir_mode=0777,sec=ntlm 0 0

Also I made my account sudoer by adding a line in /etc/sudoers

%Group ALL=(ALL:ALL) ALL


Desktop Launcher executing a sequence of commands after opening a terminal

Try creating a .sh file with all your commands in it, and then use "x-terminal-emulator -e script.sh" to run it all in the terminal.


Ubuntu 12.04 LTS error when checking for software updates

Try updating and upgrading from the command line:

sudo apt-get update
sudo apt-get upgrade

If it works, then the server was temporarily down. If not, you can enter `software souces' in dash, choose 'Software & Updates', and select a different server.


I don't know how this happened, but the problem stopped as soon as I installed a proprietary driver. Does anyone have a clue about why the system hung up in the first place and why it stopped?


I'm not intimately familiar with the software, but based on the description on its Web site, it sounds like this is a non-standard Windows driver that makes a disk look like two or more physical disks to Windows. If I'm right, the only way to access such a disk in Linux would be to write an equivalent driver for Linux, and AFAIK no such driver exists.

That said, the question is why you used this software in the first place. You say you're running Windows 8.1. If the computer shipped with this software, it almost certainly booted in EFI mode and used the GUID Partition Table (GPT) for partitioning. GPT supports over-2TiB disks, so there'd be no reason to use any third-party stuff. Even if you installed Windows yourself in BIOS/CSM/legacy mode, you could use GPT on a 4TiB data disk; only the boot disk is limited to using MBR in BIOS/CSM/legacy mode. If the computer is newer than about 2011, it probably supports EFI-mode booting. Thus, you might want to re-consider your system configuration at a fundamental level:

If your computer is BIOS-only (as are most pre-mid-2011 machines), you may be somewhat stuck -- but even then, using a sub-2TiB boot disk and your 4TB disk as a GPT data disk should work. Note that you can install Linux to a GPT disk even in BIOS mode; tying GPT to EFI is a Windows limitation, not a BIOS issue, and Linux does not share Windows' limitation on this score.
If your computer has an EFI, you can re-install Windows in EFI mode. This will use GPT, which supports your full disk capacity.

The problem with either approach, though, is that you'll need to back up your personal data and restore it after you're done re-installing.


KDE

The KDE is saving the own settings to the /home/[user]/.kde/...

The color settings are saved to the /1/:

  Colors

  The colors file follows the standard KDE colorscheme file format and
  allows a theme to define what colors work best with its theme
  elements...

  Saved at /home/[user]/.kde/share/apps/color-schemes/[unique
  name].colors ...

If you are editing the "current" color scheme then the settings are saved to the kdeglobals file - /home/[user]/.kde/share/config/kdeglobals.

Links

http://techbase.kde.org/Development/Tutorials/Plasma/ThemeDetails


X11DisplayOffset does not refer to an offset within the geometry of the display - it relates to the identification of which display clients started over the SSH connection should use in order not to interfere with local displays. From man sshd_config:

 X11DisplayOffset
         Specifies the first display number available for sshd(8)'s X11
         forwarding.  This prevents sshd from interfering with real X11
         servers.  The default is 10.

The architecture of X Windows allows for an X server to manage multiple displays. Typically on a standalone workstation with a single local user, you only have to deal with a single display - usually numbered 0 and often referred to as :0, for example in environment variable assignments like DISPLAY=:0. But on servers that may be running several X sessions (users remoting in via VNC for example, or separate X sessions on different virtual terminals) there may be multiple displays, labelled :1, :2, and so on.

When X11 forwarding over SSH is added to the mix, that adds a requirement for additional unique display numbers (so that X clients tunneled over the SSH connection get directed to the correct remote display server). In order to avoid conflicts with local displays, an offset is added to the display numbering scheme so that the remote displays are numbered :10, :11, :12, ...


You don't give much information, but you could try booting to a bootable Ubuntu USB, or CD, and then trying to perform the "fsck" manually from within there, in case it's prompting for input.


RE-encoding is likely to result in a loss of quality but by using the c:v copy and c:a copy switches, you are only moving the data from one container to another this should not result in any loss of quality. My best guess for the problem you are experiencing is issues with the  V_MS/VFW/FOURCC / WVC1 Video stream. It might be related to this bug: https://bugzilla.libav.org/show_bug.cgi?id=600

However:

Since the original file file1.mkv has no problems the easiest way is to simply use mkvpropedit to edit the properties of the mkv file for example mkvpropedit file1.mkv --set "title=New Title"

If it's not installed you can install the package with:

sudo apt-get install mkvtoolnix

Source: Experience

More Info: https://mkvtoolnix.download/doc/mkvpropedit.html


The simplescreenrecorder package is available only since 18.04 LTS.

Quick search via https://launchpad.net/ubuntu/+ppas gives the following PPA with needed package - ppa:maarten-baert/simplescreenrecorder. You can install it with:

sudo add-apt-repository ppa:maarten-baert/simplescreenrecorder
sudo apt-get update
sudo apt-get install simplescreenrecorder


Kubuntu 16.04: How to disable swap partition from auto-mounting?

Commenting out the the line that starts with /dev/sda9 by adding a # in front of it, saving and rebooting, should do the trick.


Open a terminal and type:

sudo blkid

This will list all your connected devices. Look for your USB drive containing your swap space. There will be a UUID="XXXXXXXX-XXXX-XXXX-XXXX-XXXXXXXXXXXX" entry (universally unique identifier for a device). Note the number between the quotes "".

Now type

gksudo gedit /etc/default/grub

Search for a line that begins with

GRUB_CMDLINE_LINUX=

and enter after the =

"resume=UUID=XXXXXXXX-XXXX-XXXX-XXXX-XXXXXXXXXXXX"

with the quotes! The Xs represent the number you noted after typing blkid, insert them instead of the Xs. If there already is an entry of some kind, be sure to include it in between the quotes, too.

(For example, your line might look like this:

GRUB_CMDLINE_LINUX="acpi_sleep=nonvs resume=UUID=0258cebf-0906-4b1b-af15-abb35862f180"

But do not simply copy and paste this, yours should look different!)

Save and close the file and type

sudo update-grub

This will take a small time. After it's finished, reboot. You should be all set now.


Reinstall pipelight using the correct repository:

sudo apt-add-repository ppa:pipelight/stable
sudo apt-get update
sudo apt-get install --install-recommends pipelight-multi

If none of those commands gave an error, type

sudo pipelight-plugin --update

Source: Pipelight.net/Ubuntu.


OpenSCAD has unreadably tiny interface text on UHD display

I found an answer in the run-scaled script
mentioned here: Solution for apps that don't scale on HiDPI displays.


Ubuntu 14.04 server went offline all of a sudden

You have changed or removed debian users used to maintain MySQL.
'debian-sys-maint'@'localhost'
http://www.electrictoolbox.com/restore-debian-sys-maint-mysql-user/


Ubuntu doesn't ask for password after booting

Upon Installation you may have mistakenly checked the [do not require password] option. Go into your settings and select [require my password]. That should fix it XD!


How to hide stderr without "muting" user input

You can redirect read's stderr to stdout:

read -p "Input: " x 2>&1

script.sh:

#!/bin/bash
read -p "Input: " x 2>&1


The VAPI is in the libappindicator-dev package.


Problem in installing CUDA on Intel-Nvidia hybrid graphics

If you're willing to upgrade, I successfully deployed CUDA on an unencumbered NVIDIA GPU in 16.04 .. these steps may even work in 14.x as long as you mimic the instructions regarding the .run files

Severe under performance of CUDA vs Windows, make intel primary GPU?


How to write in bash to ssh to different machine and create tmux session then run some command in it

You should divide the two actions 1) create a tmux detached session; 2) send a command/keys to it. Also maybe adding the -n option is a good idea... So your script should look like as:

#!/bin/bash
for idx in 1 2 3 4 5 6
do
    ssh -n machine$idx 'tmux new-session -d -s "myTempSession$idx"; tmux send-keys -t "myTempSession$idx" "python run.py" ENTER'
done


How to change screen brightness on Samsung R519 with nvidia driver

Open System → Administration → NVIDIA X Server Settings
Go to X Screen → X Server Color Correction
Set the Brightness to your liking.
Confirm the change by clicking on "...seconds to confirm"


Problem in apt-get update - Ubuntu 12.04?

open update manager
go to settings -> ubuntu software and unchek your CDROM
then go to other software and uncheck all CDROMs


Usually, I do backup to external HDD just several .folders simply by copying them in Krusader (I like this manager, because it recalls me old-time Norton Commander :) ).
I personally copy the following folders:

.mozilla (there are Firefox settings and other Mozilla stuff)
.thunderbird (copy of offline backup of my emails)
.skype (it's so easy to restore Skype setting and especially History by restoring this folder back)
.dropbox

Of course, you can copy other folders (like gnome-related directories). But I like to configure it 'from scratch'.

Good luck.


In the BIOS set up make the external HDD as first option.

Command:

sudo -H gedit /etc/default/grub

Opens the file "grub". Comment out the line

#GRUB_HIDDEN_TIMEOUT=0

If GRUB_TIMEOUT=0 make it GRUB_TIMEOUT=10

set GRUB_TIMEOUT_STYLE=menu if it is not already set. (Grub new versions)

save and close the file

Run:

sudo update-grub


How to prevent unwanted indicators from appearing on the panel

Go to Dash, search for Startup Applications, and uncheck those apps that you don't want starting automatically, like Skype


Grub prompts for which drives to install on after apt-get upgrade

You can try to reinstall grub in the MBR of both HDD with grub-install /dev/sda and grub-install /dev/sdb as root.

This ensures, that you can boot, even if one of your hdd is broken.

This worked for me with my 2x 500 GB at RAID 1.


Not an answer, but because that's too much for putting it into a comment.
You can read more on all of these popular threads.

Installing Ubuntu on a Pre-Installed Windows 8 (64-bit) System (UEFI Supported)
How can I install Windows after I've installed Ubuntu?
Installing Ubuntu 13.10 alongside Windows 8.1
How can I install Ubuntu without removing Windows?
Why don't I have the option ''Install Ubuntu alongside with them''
Ubuntu install and dual Boot with Windows 8 UEFI
Ubuntu 13.10 installer/live fails to boot from DVD/USB on UEFI
Install Ubuntu next to Windows 8 (UEFI dual boot)
Windows 8 removes Grub as default boot manager
Windows 8 deletes GRUB when booting


How to run Loki's port of Simcity 3000 on kubuntu 15.10 with sound on?

Solved it by installing the package osspd !!!!!!!


How do I find similar commands in terminal?

You could try something like

man -k '^cl'

This would list all the man pages that start with 'cl'. Not a direct match to your question but gives you other commands like clear, clearenv, clock etc.


ubuntu server refused public-key signature despite accepting key - from putty

Setting PermitRootLogin no means that root user is not allowed to login regardless authentication method (this is a good practice).

You can weaken this hardening by setting prohibit-password, which will block only password authentications and you can still login with private key.

But still the best option is to log in with the non-root user and for privileged actions use sudo.

Regardless the options, you need physical access or console access to fix the things up (if you don't have other user to log in with).


How can I install both 32 and 64 bit versions of the same -dev package?

You cannot install both of the -dev packages on the same system at the same time. You can only install one or the other, as they contain some of the same files. Multi-arch doesn't enable cross-compilation support, which is what you're trying to do. If you were to install the :i386 version of the sqlite development package, and build with the 64-bit compiler, you'll almost certainly have a broken build as a result.

Your best bet is to compile in a 32-bit chroot or VM, to build the 32-bit version.


docker snap: Cannot connect to the Docker daemon. Is the docker daemon running on this host?

Due to confinement issues in the evolving snappy model, Docker is not full flavored by default (see the discussion on the Snapcraft forum).

To get some helpful instructions on how to work around (i.e. break) the confinement model until the proper fix is in place. You can simply check the Docker help application packaged in the snap.

$ docker.help
Docker snap: Docker Linux container runtime.

Due to the confinement issues on snappy, it requires some manual setup to make docker-snap works on your machine.
We'll take you through the steps needed to set up docker snap work for you on ubuntu core and ubuntu classic.

On Ubuntu classic, before installing the docker snap,
please run the following command to add the login user into docker group.
    sudo addgroup --system docker
    sudo adduser $USER docker
    newgrp docker

On Ubuntu Core 16, after installing the docker snap from store,
Firstly, you need to connect the two interfaces as they're not auto-connected by default.
    sudo snap connect docker:account-control :account-control
    sudo snap connect docker:home :home

Secondly, reload the snap and allows the user to login to the new group "docker-snap".
    snap disable docker
    snap enable  docker
    newgrp docker-snap

Then have fun with docker in snappy.

The last command fails...

$ newgrp docker-snap
newgrp: group 'docker-snap' does not exist

However, I did not notice any negative impact based on the failure, and Docker now functions as I would expect.


Virtual machine installation is mandatory for Hadoop

According to the Hadoop web page, the Open Source version requires Red Hat Enterprise Linux (RHEL) 7.x - 64-bit (Docker 1.10+). The Enterprise version can work on Windows 10, Mac OSX, or RHEL.

Sounds like you'll need a virtual machine like Virtualbox, running RHEL, at minimum. I'd recommend doing more research to see if Virtualbox is realistic to run this, based on available resources.

If you're dual-booting Windows 10 and Ubuntu, installing under Windows 10 might provide better results.

Cheers, Al


Ubuntu version with lesser system requirement

I found on the ubuntu homepage (Ubuntu Help page) that since ubuntu 11.04 you need 1000 ΜHz processor, 1024 MiB RAM, 3D Acceleration Capable Videocard with at least 256 MB. So your system should be googd enough.

If you want to install something smaller try Xubuntu or Lubuntu instead which only need 512 MiB of system memory (RAM).

Personally I use Ubuntu 16.04 on an old dell notebook together with Windows7 without any problems.

My System: old Dell, Intel Core i7 CPU Q720 @ 1.60 GHz, Grafic: AMD RV730 and 4 GB RAM


Why are my colors separated/shifted when using obs/v4l2sink/v4l2loopback?

You need to set the format to YUY2 and set the same dimensions on OBS and v4l2 device.
I solve my issue of "not supported format" by:

removing v4l2loopback-utils and then installing v4l2loopback-dkms
set YUY2 on v4l2sink menu

The credits are for https://github.com/CatxFish/obs-v4l2sink/issues/5#issuecomment-618336414


It seems that when Core is first configured it is unaware of regional Keyboard_layout types. As I'm using a UK keyboard type, the " key and the @ are swapped with respect to the US keyboard. Therefore I simply needed to press Shift+2 to get the @ character.
For more details reference Keyboard layout - Wikipedia.


How to setup separate SSD for EFI partition and bootloader for dualboot Linux and MacOS

First, your partitioning is wasteful. A basic installation requires one partition, for root (/). (Another may be needed for the boot loader; more on that later.) In this configuration, all directories and subdirectories are on this partition. When you create another partition, it's mounted somewhere that you specify in this directory tree, thus relieving some of the space requirements on root (/) and enabling various benefits.

The problem with your setup is that devoting an entire disk to some of your partitions is wasteful:

/usr is not likely to hold more than about 20 GB of files. These files are the bulk of the Linux system, so putting /usr on a hard disk and root (/) on an SSD will actually degrade performance compared to putting both on the SSD. The only reason I'd do this is if the SSD is tiny -- and such a tiny SSD suggests an old one, which might no longer be reliable.
The EFI System Partition (ESP) holds just a few megabytes of files, but for various reasons related to EFI quirks, I recommend making it 550 MiB or larger -- but certainly not big enough to devote a whole disk to it, assuming a non-ancient disk. Furthermore, the ESP is used only at boot time or when updating the boot loader. Thus, devoting an entire SSD to the ESP means throwing away the SSD's speed benefits.

A better plan is to use your SSD(s) for a root (/) filesystem without a separate /usr filesystem, to put /home on your hard disks, and to create a separate ESP wherever it's convenient. If you want to use all four of your disks, you should seriously consider using Logical Volume Management (LVM), which enables combining multiple partitions (physical volumes, in LVM-speak) into one volume group, which is then carved up into logical volumes that hold your filesystems. (Note: Logical volumes are not the same as logical partitions, which are an unrelated MBR partitioning construct.) You can therefore create a single big logical volume that spans multiple disks. Controlling the split between your SSDs and hard disks requires more advanced LVM techniques, or you could create two volume groups, one for your hard disks and one for the SSDs.

  Ubuntu let me choose where to install the bootloader and i choosed sdd.

When installing in EFI/UEFI mode, the Ubuntu installer does not prompt for where to install the boot loader. Instead, it detects the ESP and automatically installs the boot loader there. Thus, I suspect you may have accidentally booted in BIOS/CSM/legacy mode. See my page on the CSM for further information on this topic, including tips on controlling how you boot.

This problem may well be why you received an error when installing GRUB. In a BIOS-mode install, GRUB works best with a BIOS Boot Partition, which you probably didn't create. If it's not present, the Ubuntu installer will complain. I can't be sure of this, though, because you haven't said what the error message was. (Side note: When asking for help, always present the complete error message. Nine times out of ten, summaries omit the most important details.)

That said, I'm not sure what caused the error: failure reading sector 0xXXX hd1 message you report getting from GRUB. It could be related to the installation error, or it could be that your disk is defective.

  Is there a way i could format sdd and install the EFI partition and a bootloader (which is able to boot linux and macosx)

Hold the phone! Are you saying this is a dual-boot with OS X? If so, that's a critical detail, and detailed information on your partitions is required to give a coherent answer to your question. Please post that information. (The output of sudo parted -l should do the trick. Be sure to edit your original question; do not try to cram that information into a comment -- but do add a comment to this reply so I'll be informed of your new information.)

EDIT:

In EFI mode, typing sudo grub-install causes it to install to the ESP (I believe the one mounted at /boot/efi by default, but I'm not 100% positive of that). Thus, there's no need to specify a disk device. Certainly it's not installed to a whole-disk device, but to a partition. Thus, any prompt you're seeing in the Ubuntu installer about this is misleading. It's possible that the system is getting confused because you've got so many disks, and it would work better if you'd create an ESP on /dev/sda.

Dual-booting a standard PC (you say it's a Supermicro board) with Linux and OS X is tricky at best. This practice is even of debatable legality in many countries. I don't know what this forum's policy is on discussing the topic, but certainly, when you get to actually configuring that part of it, you're better off asking on a Hackintosh-specific forum.

Using a separate /usr partition used to be common practice, but is rare today. I don't know offhand if Ubuntu even supports this configuration any more. If it does, it shouldn't take anything particularly special to set it up; however, I advise you to be very certain about where the huge program files you're anticipating will go. Even a heavily-loaded Ubuntu system is unlikely to need more than 20-30 GiB of disk space. Many big programs store their files in users' home directories or in particular subdirectories that might be better split off. Doing this may be better than putting /usr on your hard disk, since you'll see a speed drop when you do that. If you could say what programs you're installing that require massive amounts of space, perhaps somebody could offer better guidance on this score.


urxvt has a -hold|+hold option to “not immediately destroy its window when the program executed within it exits” (see man urxvt):

urxvt -geometry 40x20+990+30 -w 0 -b 0 -hold -e cal

A different approach would be to spawn a shell (which doesn’t just exit) to keep the window open:

urxvt -geometry 40x20+990+30 -w 0 -b 0 -e 'cal;sh'


Desktopcouch is part of Ubuntu One. If you want to stop that uncheck it in startup applications. And the problem you have is a bug so please login/register at launchpad and add yourself to the 'Does this bug affect you?'. That way it'll get more attention!

Turning it off will probably also take care of ubuntuone-syncd


OS display/input freezes when typing quickly

I have the exact same keyboard as this question here. For anyone who has the same issue, it's likely you have a mechanical keyboard that's in NKRO mode, which creates this issue. Changing it to 6KRO fixed the issue.


You can get a lot of themes from http://gnome-looks.org

The safest way is to create a .themes directory in your home for themes and .icons for icon themes.

You can also, but not recommend, extract the archives you download, and move the correct theme folder to /usr/share/themes
A theme folder consist of elements like gtk-2.0, gtk-3.0, metacity-1, unity, index.theme

You will need to start the file manager as super user when copying the themes:

gksudo nautilus

I personally avoid this because you could wrongly and unintentionally delete some important system file.

Install unity-tweak-tool from Ubuntu Software Center to change the themes.


How to make your ubuntu filesystem read-only

If, as is likely, when you connect this drive to another Ubuntu machine, it is automatically mounted, you can quite simply remount it as read-only, so its files cannot be altered. In order to learn the /dev/ info and the /media location where it is mounted, simply type mount. Now, with that information, and without even unmounting the drive you wish to be read only, type:

sudo mount -o remount,ro /dev/sdb1 /media/MDrive

Obviously, replace sdb1 and MDrive with the locations and names of your drive. If you ever need it to be writable again, type:

sudo mount -o remount,rw /dev/sdb1 /media/MDrive

There is no way to write protect a hard disk, however, apart from encrypting the entire device.

(If the external disk is not automounted, you will need to do the following: sudo mkdir /media/disk and then sudo mount -t vfat /dev/sdb1 /media/disk -o ro, again replacing vfat with whatever filesystem the disk uses, and /dev with your device node.)


How can I change the nvidia GPU fan speed?

In the terminal run:

sudo nvidia-xconfig
sudo nvidia-xconfig --cool-bits=4

restart your computer and search for NVIDIA X Server Settings in the Dash. There should be an option to change fan speed under Thermal Settings.


How to redirect single audio channels to different devices?

You can use a package called Jack. What it lets you do is pipe the outputs from the source, into whatever channels on whatever devices you want.

sudo apt-get jack2d jack-tools qjackctl

jack2d: is the more recent version of Jack

jack-tools: more stuff for jack

qjackctl: GUI

After installation use qjackctl to pull up the GUI.

Examples of things you can do with jack;

Pipe audio from one source to all devices for synced audio.
Send the Left channel to both channels of a pair of speakers, and the right to a different pair

The possibilities are pretty endless. Here is a picture from the help page for Jack

On the left, you can see your output sources, and on the right are the devices you can output to.

Here is a picture of 3 LR audio sources where 2 of them are pipe to 1 speaker,

and the other source to the other speaker.


How can I get the Sound Indicator to show the track's file name?

I figured it out through Google searches :)

I installed EasyTAG and used it to auto-fill all the tracks using the song's file name. Now, the sound indicator shows the same information as the file names :) This also fixed the title bar entry in Amarok.

The code to install EasyTAG is:

sudo apt-get install easytag