First You must check if Network Manager is managing your network interface.

Open a terminal, Press Ctrl+Alt+T

Run it:

sudo -i
nmcli dev status

The above command will list all existing network interfaces along with their state.
If state is shown as unmanaged, this means Network Manager is not controlling a corresponding interface.
If state displays any other values:

DEVICE     TYPE              STATE
eth0      802-3-ethernet   connected

It implies that a given interface is managed by Network Manager.

To disable Network Manager for your eth0, you can do the following.

Edit the Network Manager configuration file in /etc/NetworkManager, and set:

managed=false

In the terminal continue running:

nano /etc/NetworkManager/NetworkManager.conf

And write the following lines:

[ifupdown]
managed=false

Ctrl + O, save file. Ctrl + X, close nano.

Then in /etc/network/interfaces, add information about the interface you want to disable Network Manager for.

In the terminal continue running:

nano /etc/network/interfaces

And write the following lines:

# The loopback network interface
auto lo
iface lo inet loopback

# eth0 not managed by Network Manager
allow-hotplug eth0
iface eth0 inet static
address 192.168.0.146
netmask 255.255.255.0
gateway 192.168.0.1
dns-nameservers 208.67.222.222 #DNS OpenDns

Now Network Manager automatically ignore any interfaces specified in file:

/etc/network/interfaces

And stop managing them.

After rebooting, verify that Network Manager is successfully disabled for eth0:

sudo -i
nmcli dev status

DEVICE     TYPE              STATE
eth0      802-3-ethernet   unmanaged


Your .yaml file has extra space characters in it. .yaml files are very fussy about indents, spacing, and no tabs. You also didn't include your en02: code. Try this skeleton, and see if it works for you.

network:
  version: 2
  renderer: networkd
  ethernets:
    eno1:
      optional: true
    en02:
      match:
        macaddress: "11:22:33:44:55:66"
      optional: true
  bridges:
    br212:
      interfaces: [vlan212]
      dhcp4: true
  vlans:
    vlan212:
      accept-ra: no
      id: 212
      link: eno2


The first thing I would try is to verify that /etc/X11/xorg.conf.d/51.synaptics.conf file is really taken into account by X server. Add Option "Ignore" "on" line to the InputClass section and reboot. If your touchpad is disabled, your configuration really works.

A touchpad moving by itself really looks like a hardware issue, perhaps damage from the liquids spilled on it in the past, or some dust grains stuck between the touch surface and the bezel. Try to clean the touchpad as much as you can (if you feel comfortable with taking the laptop apart, remove the touchpad, clean it and put it back). If that doesn't help, you may need get it replaced, or disable it and leart to do without.


Yes, as you can see at https://get.adobe.com/se/flashplayer/about/ Adobe updates it for Linux too.
But the Canonical folks seem not be so fast with updating the adobe-flashplugin package as they used to be, and the latest adobe-flashplugin provides version 32.0.0.414 which unfortunately is not the latest Flash Player version.
One way to fix it for you is to download if from here and (assuming you use Firefox) manually replace /usr/lib/adobe-flashplugin/libflashplayer.so with the downloaded version of libflashplayer.so.


The requested URL was not found on this server

On ubuntu enabling module rewrite by running
sudo a2enmod rewrite
and then retart apache2 service with
service apache2 restart will solve your problem


how can I increase my swap space in this sitution?

You can not manipulate (change) a partition that the system is currently using.You will have to use a live environment so as to resize your partitions.
In your case your system is using both system partition - dev/sda4 and the swap area dev/sda5.


Is the Ubuntu kernel 100% free software?

No, ubuntu kernel is not 100% free, It includes some non free kernel blobs.
source: http://www.gnu.org/distros/common-distros.html (just look for ubuntu)

There is an another distro called gNewsense which is based on ubuntu but removed all traces of non free components.
For a list of 100% free distributions, look at http://www.gnu.org/distros/free-distros.html


How to change the description of a catkin package?

To edit the catkin package, simply go to the workspace folder where the package is located and open it with your favourite editor or access via the GUI of the Files application.


Can uninstalling unused shipped software criple future Ubuntu upgrades?

No.

Uninstalling software that you don't use or want will not burst your PC into flames, cause an earthquake or destroy the planet, so don't worry as long as you don't Uninstall  needed software in which case you have to know what exactly you're uninstalling.


Software center is broken and can not be repaired or reinstalled

Try sudo apt-get -f install. If it doesn't solve the problem try sudo apt-get autoclean. Third I would try sudo apt-get autoremove wine1.4.


Must manually restart lightdm to have it appear

systemctl enable lightdm will enable the service on boot


Every time a new machine or unit is created it increments that count in the model. In order to reset the counts you would need a new model.

https://jujucharms.com/docs/devel/models
https://jujucharms.com/docs/devel/models-adding


I can't install Ubuntu 20.04 along side windows 10

I don't know exactly how you partitioned your disk, but the proper way is to create a separate partition for Ubuntu formatted with ext4 file system. You will need to shrink your Windows partition first, then create a new primary partition in unallocated free space on your disk drive, format it with ext4 and set it as "/" (root file system). You can also create a separate "swap" partition or set the "swap" file on the "root" partition. When Ubuntu is installed, after reboot you should see both Ubuntu and Windows available as boot choices.


Stuck at GRUB command line after installation on Dell 5558

1) Your USB drive needs to be formatted as FAT32

2) I found https://rufus.akeo.ie/ to be very reliable for UEFI (recent, > 2009) systems (this may not be the case with universal USB installer)


Ubuntu 12.04 fails to boot (UEFI) after motherboard changed

I know for example about grub and UUID's for harddisks. I just learned they are generated differently on another Mainboard if what i was reading is true. So you need to replace the UUIDS for your harddisks in /etc/fstab with the actual divices /dev/sd* most likely.

You could look into the outputs of this and figure out how to put the new UUID's in if they changed

sudo fdisk -l
sudo blkid
cat /etc/fstab

Show us the output of this if your stuck. Also look into custom grub files if you have any then do a update-grub on the disk after you mounted it. You might need to chroot on that disk as well. Or run some grub repair stuff from the livecd or use superbootdisk/supergrubdisk? or something like that. But i am not sure if they are fixing the fstab.

Why would you expect that everything just works fine? Ubuntu is configured to that old main-board and probably need to be configured in a different way for the new one.

A live CD/DVD will probably work because it detects hardware on boot without loading any specific settings.

I would just backup the old system, and install a fresh ubuntu, and overwrite some settings from the old system (maybe just the entire home folder and something in /etc ...)


Install gnome-screensaver

sudo apt-get install gnome-screensaver


How can I add folder shortcuts to the Launcher?

There are two ways:

Dynamically

You can add a shortcut to a folder by browsing (in nautilus) into the folder you want to add, and choose "add bookmark" from the bookmark menu. Alternatively, you can press Ctrl+D. Bookmarks you created this way are added automatically to the Files icon in the launcher, in the top section (Nautilus adds these shortcuts to the file: ~/.config/gtk-3.0/bookmarks).

In the "static" section of the launcher's icon.

Alternatively, you can add a shortcut to the Files icon (or any other icon), by editing its .desktop file. This method gives you more control over the name of the shortcut, and the order of shortcuts, if you have more than one.

To do that, first copy the .desktop file to ~/.local/share/applications

cp /usr/share/applications/nautilus.desktop  ~/.local/share/applications/nautilus.desktop

Open the (copied) file with gedit; it won't open by double-click, so open a gedit window and drag the file over the gedit window.
Look for the line:

Actions=Window;

Add a name that you would like to give your folder in the launcher:

Actions=Window;YourFolder;

At the end of the file, add a section like this:

[Desktop Action YourFolder]
Name=YourFolder
Exec=nautilus /path/to/thefolder
OnlyShowIn=Unity;

Log out and back in, now you'll have your shortcut in the Files icon by right-click.

Explanation:

Icons in Dash and the launcher represent .desktop files. These icons have one "main" command (that's what happens if you click on it), but also can have a number of shortcuts (accessible by right-click).

This "main" command can be found in the Exec= line, in the section directly below [Desktop Entry], the shortcuts are listed in the line Actions=, and defined in the [Desktop Action YourFolder] - section(s).

.desktop files in ~/.local/share/applications overrule the ones in /usr/share/applications, but the first time after you copy the original to the local directory, you have to log out/in. The clean procedure is always to edit the local one and leave the original untouched.

Note:

Bookmarks that you created by the first method, are added to the icon automatically, but are not part of the nautilus.desktop file.

Edit for 15.04 and later

The answer above applies for 15.04 and above as well, but the launcher to edit (locally copied) for the static section is:

/usr/share/applications/org.gnome.Nautilus.desktop

instead of

/usr/share/applications/nautilus.desktop


Permission denied while you saving means you dont have permission to save the file in that location, you might tried to save your file in root directly which ofcourse requires sudo..

Try below options

Use below command to give full permission for that folder where you are trying to save your file to all the user accounts in that system so that you can save without opening your editor with sudo

  sudo chmod 777 (full folder path)

Try to save file in your user account specific home or desktop folder, you don't need sudo for this..

Beauty of linux is SUDO. Use it only whereever necessary.


Can software for Ubuntu Desktop work on Ubuntu touch unmodified?

The short answer is: No.

The long answer is: Yes, if the app was written in Qt 5 or HTML, and was capable of running on the limit screen size and interacting with touch input and on-screen-keyboard, then it would run.  But most apps written originally for the desktop won't meet that criteria.

The even longer answer is: This is why we developed the Ubuntu SDK, it's a toolkit designed to allow apps to be developed for desktops, phones and tablets (and TVs).  It has resolution-independence built it, it support multiple display servers already, and it's being designed to adapt appropriately between touch and keyboard/mouse inputs.  Eventually we hope that the majority of Ubuntu's apps will work seemlessly across all of our supported form factors, and the Ubuntu SDK is how we plan to get there.


Off the top of my head - if the printer light is blinking it could be something simple in the settings like the wrong paper size or paper tray option.

When I had an issue installing my ip5200 I did read a forum post about other Canon drivers but then my printer started working so I didn't need them.


If you can get to a terminal and have networking (?), many times you can repair a failed upgrade with:

 sudo apt-get -f install

then...

sudo apt full-upgrade

After those have run, do the usual apt update and apt full-upgrade again (with sudo) and see if there are any more errors.

If the problem is the windowing system, you can sometimes remedy that by just reinstalling the window manager you use with --reinstall option, eg like:

sudo apt-get install --reinstall gnome

(I had this happen with a recent VMWare image and it was a bit of a pain to get working again, make sure you check permissions in your home directory if you have to do this...)


Why do I not have the $MAIL environment variable?

The $MAIL variable points to the location of your system mail account (i.e. where Postfix, Exim, ... would drop your mails when using the sendmail or mail to send a mail to a local user), however this variable is not used by any graphical E-Mail client I know of -- Which is probably why is its not defined.

Thunderbird stores your E-Mail in these directories:

~/.thunderbird/<ProfileName>/Mail for local messages (sent messages and messages obtained via POP3)
~/.thunderbird/<ProfileName>/ImapMail for downloaded IMAP messages

Note: <ProfileName> is the name of your user Thunderbird user profile and will look similar to this: e7d2hvg8.default.


Microphone does not work on Asus VivoBook X202E

I had a problem with microphone in Ubuntu 14.04 LTE on my ASUS Vivobook X202E too.

Here where I found the solution: http://ubuntuforums.org/showthread.php?t=2203855&p=13084887#post13084887

What you need to do is:

run alsamixer in terminal
press in F4 in AlsaMixer to switch to Capture tab
using left/right arrows choose Mic Boost control
using q key set left part of Mic Boost bar to 100%, using c key set right part to 0
using up/down keys set Capture bar to 100 (both for R and L)

That's it.


how to use regular expression with iptables

The problem is that you are attempting to use a relatively slow pattern matching algorithm in an application that MUST use a fast pattern matching algorithm. Also know that the entire use of the "string" filter can be compute intensive, and for that reason just a few years ago that module was not available by default. You will have to learn either the Boyer-Moore (bm) or Knuth-Pratt-Morris (kmp) fast string matching algorithms and use one of those.

See also the manual pages for iptables-extensions. Excerpt:

   --algo {bm|kmp}
          Select the pattern matching strategy. (bm = Boyer-Moore, kmp = Knuth-Pratt-Morris)


Allow fullscreen - where is this list stored?

If you were using YouTube's HTML 5 player (as the "never ask again" in the popup suggests), the fullscreen setting is managed by Firefox (and therefore has nothing to do with Ubuntu or Gnome).

Go to about:permissions (just copy it into your address bar), select www.youtube.com from the list and change the setting in the Fullscreen box.


Can not install Nginx (error in installing)

If you've installed apache2 first stop it. Then try to install

sudo service apache2 stop


How can I upgrade my EOL 16.10 to any new version?

Ubuntu only supports upgrading from LTS (long term support) to LTS, or from one intermediate version to the next. If you are going to use intermediate versions, you have to update every 6 months to avoid being caught in this situation.

Make a backup of important data before attempting updates in case something goes wrong. You have three options:

Fresh Install

Do a fresh install of 16.04 (LTS) or 17.10. In the options menu elect "Something else", specify the partition to use, and make sure the "Do Not Format" is marked. If you don't format the drive then your personal files should be safe.

Wait for 18.04

18.04 is the next LTS, It will be released in April. Perhaps you will be allowed to upgrade to it.

Manually upgrade

Manually upgrading is not officially supported and requires knowledge of package management.

Edit /etc/apt/sources.list and change "yackkety' to "artful". And save.
Do the following commands:

sudo apt-get update
sudo apt-get upgrade
sudo apt-get dist-upgrade
sudo apt-get autoremove

Now you will likely have some obsolete package left behind as dist-upgrade does as few removals as possible. So we need to clean up. I find aptitude is an excellent tool for this. Open aptitude and navigate to the "Obsolete Packages" heading. these packages were replaced by another package but were not removed because they break other packages. In most cases the package they break was also obsoleted; however, carefully review what aptitude will do when removing each package.

Note: 17.10 uses Wayland by default instead of Xorg, so this third step may be lengthy in your case. This change may also cause this method to fail horribly.


Apt-get update connection failed, but wget is OK

For servers in China, use China repos with https.

https://mirror.tuna.tsinghua.edu.cn/help/ubuntu/

edit your /etc/apt/sources.list and put those mirrors instead.


grub2: Booting operating system booted last time, the "saved method", throws "error: Diskfilter writes are not supported". How to resolve?

You didn't make it clear as to which GRUB file you edited, and what changes that you made. Revert whatever edits you made.
You never should edit /boot/grub/grub.cfg.
You do want to edit /etc/default/grub. Making the following changes...
GRUB_DEFAULT=saved    <- edit this existing line
GRUB_SAVEDEFAULT=true <- add this line

This will allow GRUB to remember the last OS that you booted, until such time you select a different OS to boot.
sudo update-grub # write changes to disk
reboot # reboot the computer
Update #1:
This won't work on LVM.
See here and here for more info about this.


Thunderbird Google calendar tab acts as mobile browser

This seems to be a bug on Google's end.

A workaround, as described here, is to go to Tools -> Add-ons -> Extensions, click Preferences for the Google Calendar Tab plug-in and activate Google Apps for your domain with the following URL:

https://www.google.com/calendar/render


Which release would fit my Dell Inspiron N4030?

The latest LTS (Long Term Support) version would suit you just fine.  Go with the 32x version.  You can download it from the main download page.

http://www.ubuntu.com/download/desktop

If it's too slow, try LXDE.
sudo apt-get install lxde-desktop

LXDE and openbox will then be available on the login screen.  (After you log out, not lock.)

Openbox is fast, LXDE is easy.


Open in Terminal context menu only opens terminal in home directory

Install the package nautilus-open-terminal:

sudo apt-get install nautilus-open-terminal

The bad news is that you will have two options now in your right-click menu. The good news is that one of them works.


Installing Itunes on PlayOnlinux with Ubuntu 16.04 LTS

Found out everything i needed to know... PlayOnlinux is a pure waste wine (Staging) is the way to go...
latest Itunes 12 installed and running perfectly!
LINUX
Wine Programs Not Working? Try These Steps


"What's New" is missing in Software Centre

Uninstall and then re-install Ubuntu Software Center:

Press  CTRL+ALT+T  simultaneously to open the terminal.

To uninstall Software Center:

sudo apt-get remove software-center
sudo apt-get autoremove software-center

To re-install Software Center:

sudo apt-get install software-center
sudo apt-get update

that should bring it back...


Are there any files stored on my hard drive when I am running the Live USB version of Ubuntu?

This depends the way you created the live USB.
If you setup persistence then data will be stored in a special file called casper-rw (for Ubuntu). Check the below link for more information:

http://www.linuxliveusb.com/en/help/faq/persistence/67-what-is-persistence


Bluetooth Headset not properly working after idle

This happens to me too and is very annoying.

Fastest manual solution is go to Sound settings, switch to Built-in-Audio, wait 3 seconds, switch back.

I wrote a small script that is doing exactly this for me. I put it as a keyboard shortcut, so it's quicker.

#!/bin/bash
internal="1";
bluez=$(pactl list sinks short | grep -Po "^[0-9]+(?=.*?bluez)");

if [ ! -z "$bluez" ]; then
  while IFS= read -r input; do
     pacmd move-sink-input $input $internal;
  done < <(pactl list sink-inputs | grep -Po "(?<=Sink Input #)[0-9]+")
  sleep 3;
  while IFS= read -r input; do
     pacmd move-sink-input $input $bluez;
  done < <(pactl list sink-inputs | grep -Po "(?<=Sink Input #)[0-9]+")
fi

You might need to change internal to something else, you can find out with running pactl list sinks short.

That helps a bit, but is no permanent solution !


QtCreator : set device-debug to WLAN-SSH without USB

Yes it is possible but right now a little bit tricky.

Get the IP-address of your Ubuntu Touch device.

adb shell
ip addr show wlan0

edit the file menu.json

sudo nano /usr/share/qtcreator/ubuntu/menu.json

remove there 'p2222' and change 127.0.0.1 to the IP-Address from (1.)

Restart the QT-Creator and run your application with Ctrl + F12.

I tried it with my N7 and it worked.

Problems:

You have to connect via USB to get your mobiles IP address. (I don't know how we can figure out on the mobile itself)
You have to change the file menu.json every time the IP-address changes.


Sleep won't work and the touch/clickpad is a mess on a HP Envy 15

All guys that have the HP Envy computers are suffering the same issue, I could fix some of them on my box. I`m continuous looking for this blog, your touchpad is easy to fix it.

The sleep issue could be the bright of the monitor, did you tried to increase the monitor bright using Function Button + F3?

Please, don`t forget to update this post!

Cheers


How to install/update wayland without building it?

Wayland is actually one of the easiest softwares to build from source since it has very few dependencies.

As per the README, you'll need libffi, and if you start building, you'll also hear it ask for libxml2.

# apt-get install --no-install-recommends libffi-dev libxml2-dev

Then, just build and install as usual. Instead of make install, you can try checkinstall for ease of uninstall at a later date.

./autogen.sh #(old versions use ./configure)
sudo checkinstall #(or use make install)

That's everything. Maybe restart your compositor so it'll take advantage of the new libraries.

  What do I need these release files then for if they tell me to go to gitlab and clone and make.

The "release" is a frozen source archive. The GitLab business in the README is an oversight because someone forgot to change the instructions for the tarball.

ALT: cosmic has wayland-protocols v1.16 in the repos. If you don't mind trying out unreleased software, you can perform a full system upgrade. (Note that downgrading is not supported, so make backups first.)


Check how cheese is garbbing it...directly/uvc/whatever...you may also want to check into manually setting resolution.  skype could be defaulting to a resolution not supported my your camera.

edit: I wouldn't think skype would refuse 640x480, try lower resolutions in cheese.  It should set the capture size on the cam...If it works we can walk through setting it manually.  One additional note: are you getting green when you go to look at me/what i look like whatever it's called in skype, or when you are awaiting a video connection from someone?


How do invert my touchpad's orientation?

There is an available modification for the Synaptics driver and client that works nicely for me and for others. There are two drawbacks to mention:

It involves installing and using development tools such as automake.
You'll have to repeat it with each upgrade of the Synaptics driver.

There is a bug report requesting to add the orientation parameter to the stock Synaptics driver and client. The bug report is referenced in a broader idea report involving manual  and automatic orientation of touchpads and touchscreens.


Accent marks on WPS Office in Kubuntu 18.04 doesn't work


How to uninstall laptop-mode-tools installed from an .tar.gz archive?

You have installed the DEB file eg. laptop-mode-tools_1.52-1ubuntu2_all.deb. The version is not decisive.
Therefore
sudo apt-get remove laptop-mode-tools

If you compiled it yourself from an archive. Goto the source folder and run
sudo make uninstall

If this not work, follow these steps:

Install checkinstall
 sudo apt-get install checkinstall

Go into the laptop-mode-tools source folder and compile the tools again

Start the installation with this command
(The command installs a DEB package and replaces your previous installation)
 sudo checkinstall

Remove the package
 sudo apt-get remove laptop-mode-tools


Not able to install rJava in R (ubuntu 18.04)

In my case, I also had to use: sudo R CMD javareconf, to make it work.


Best way to clone an installation (copying to identical hardware)

Clonezilla sounds like it fits your needs


How do I setup SSH/SFTP on two systems to transfer files between them?

Try rsync

rsync -avz /origin/path/ username@69.69.69.60:/destination/path/


GNOME Sushi preview not working for video files

Install 3 packages by the command below:

apt-get install -y gstreamer1.0-gtk3 gstreamer1.0-pulseaudio gstreamer1.0-libav

It works for me on Ubuntu 20.04.


How to install cuda10.1 on ubuntu20.04 in a custom location

Yes, but keep in mind that this will probably not work since GPU acceleration under WSL (it's not clear if you're running under it or a VM) is not officially supported yet. In case you're running under WSL, there's a public preview available from nvidia, but it seems to only offer CUDA 11.
In case you still want to install version 10.1 in a different folder, you'll need to download the installer from nvidia's site:
wget http://developer.download.nvidia.com/compute/cuda/10.1/Prod/local_installers/cuda_10.1.243_418.87.00_linux.run

And, from the installer's help page:

--installpath=
Install everything to the  directory. This flag sets the same values
as the toolkitpath, samplespath, and librarypath options.

So you can set this flag to whatever path you want to when running the installer.


How Do I Open Fixed Window In Firefox (like Chrome app mode)?

I was looking for something like this for a while, so here is how I made my own Firefox 'app' mode.

For Googlenauts with Windows/Mac 'Set Up Firefox' & 'Alternatively...' should also work on other OSs, perhaps with a few tweaks to the commands used, whilst 'Create Launcher' should work only for most Desktop Environments that implement the freedesktop 'specifactions'.

Set Up Firefox

First run firefox --ProfileManager from terminal (you may need to close any running instances of Firefox first, or use the -new-instance option).Create a new profile and call it app. Select the 'Default' one (IMPORTANT: otherwise by default it will start the app profile you are creating) and press 'Exit'.

Now run firefox -P app. This will start Firefox from the new app profile you just created. As removing the tabs and navigation bar is now difficult or impossible in Firefox's settings, you will need to install some extensions to remove them - these ones work, though may be better ones available that hide the bars permanently:

Hide Tab bar with one Tab - hides the tab bar when there is only one tab open.
Hide Navigation Bar - you need to press F2 to show/hide the nav bar

Edit: Both options of hiding the tab+nav bars is also included with Classic Theme Restorer - small icons can also be set for a more compact layout.

Now, when you run firefox -P app -new-instance http://URL (e.g. firefox -P app -new-instance https://askubuntu.com/q/487936/178596), you should get a Firefox window like this:

Also, when you open Firefox by running firefox or clicking the Firefox button, it should open your normal Firefox profile with the tab and nav bars.

Works in Firefox 30.0, 40.0, partially tested in 52.

Create Launcher

You probably want to create a launcher to open your app from the menu - you can do so using this template:

[Desktop Entry]
Name=<APP NAME>
GenericName=<APP NAME>
#Comment=Browse the Web
Exec=firefox -P app -new-instance <https://URL>
Icon=<ICON>
Terminal=false
Type=Application
#MimeType=text/html;text/xml;application/xhtml+xml;application/vnd.mozilla.xul+xml;text/mml;x-scheme-handler/http;x-scheme-handler/https;
StartupNotify=true
#Categories=Network;WebBrowser;
Keywords=<KEYWORDS>

Where:

<APP NAME> is the name of your app
<https://URL> is the URL you want shown by default on launching the app. -new-instance is optional but allows the Firefox App to be run as the same time as normal Firefox. See also: Mozilla Developer - Command Line options and the output of firefox --help.
<ICON> is the name of a icon /usr/share/icons or ~/.local/share/icons, or the path to a icon file (preferably PNG or SVG I think).
<KEYWORDS> - Relevant keywords delimited by ;, you can include words you can use to search for the launcher in the Dash/Menu - e.g. Paper;Ink;Toner; - Optional: comment it out with a # at the beginning of the line if you don't use this.

For more info on how .desktop files work, you can read this

You can also follow both above steps, and create various different app profiles, just remember if you use a different name to app - e.g. gmailapp, you need to use that name consistently instead of app.

Also, I'm not sure the -new-instance option is needed much any more, I have left it in anyway.

See also:
 - https://superuser.com/questions/468580/create-application-shortcut-chromes-feature-in-firefox

Alternatively...

I was looking for a solution to create a script so I could run a command and create Firefox apps (so without extensions etc), and the following userChrome.css works well at hiding all the toolbars:

@namespace url("http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul");
#TabsToolbar,
#PersonalToolbar,
#BookmarksToolbar,
#MenuToolbar,
#tabbrowser-tabs,
#nav-bar,
#TabsToolbar { display: none !important; }

I haven't tested it too much yet, thought it will be annoying to use since it hides all the open tabs....


Headset microphone not working on Ubuntu 20.10 with Realtek ALC289 codec

Also not working for me either, though it DID work when I first had Ubuntu installed. After upgrading bluetooth drivers and maybe installing some other sound packages, it stopped working. Input shows, and very tiny pickup of static noise, but nothing else.


Virtual Machine (Ubuntu) cannot connect to internet

1- edit the file " interfaces":

sudo nano /etc/network/interfaces

2- then make sure this line is in that file :

iface eth0 inet dhcp

3- run dhclient

4- run ping 8.8.8.8


How do I change a document's extension / file extension / file format?

Forget about the concept of "file extensions" that thing is completely made up and useless. For example somebody could rename a music file on your system to garbage.gbr and since windows interprets extensions literally as file types it wouldn't even know that the file was a music file.

In Ubuntu on the other hand, you can name a file whatever you wish. You don't even have to choose an extension if you don't feel like it. Ubuntu will read the MIME type of the file and understand what type it is. Based on the file type it will associate it to the appropriate program to open it. You still have all the control you need. You can change the default program associated with a MIME type in several ways.

To change default program association of a file type, just right click on a file with that type and choose Properties and go to Open With tab.

Now that being said, I should mention that extensions are not completely useless in Ubuntu. They still provide a standard way to tag a file for easy identification of its type -- but they don't set the file type. The only exception to this is when saving a file in some applications that support saving in several different formats. When you provide a file name in those application it can read the extension you provided and based on that decides how to create and save your new file with the correct mime type. For example if you open a JPEG file in GIMP and then choose save as ... and enter image.png, GIMP opens the PNG file dialogue and lets you save the file with PNG MIME Type.


Sound coming from both speakers and headphones on ubuntu 14.04

In Alsa mixer, under "Auto Mute" tab change the selection to "Line out"
It must have been "Disabled" before. Worked for me.


Can't boot Windows 8 after installing Ubuntu 13.10 in legacy mode

If you have a Windows re-install disc you can use dism to re-write your Windows bootloader, however this will Disable your ability to boot Ubuntu and require you to re-install ubuntu.

In WINDOWS command prompt type:

"bcdboot C:\Windows /s E: /f UEFI" (C is your windows location, change accordingly. E is your UEFI partition, change accordingly as your drive letters may differ). To see what drive letters to use type "notepad" into the command prompt then "File/Open" to browse so you can see what letters are in use. If your UEFI parition isn't mounted which it likely won't be then you will need to do so by in command prompt typing "diskpart", "list disk", "select disk 0" (or whatever disk it's on), "select partition 0" (or whatever partition it is), "assign letter=q" (or whatever letter you want to use that is currently free).

If you don't have a windows re-install disc you can always download the Windows 8.1 - Enterprise X86-64 iso file. Registration is required.

http://technet.microsoft.com/en-ca/evalcenter/hh699156.aspx?ocid=wc-mscom-ent


16.04: Filezilla crashes when performing any remote action

I had set up the "deb http://archive.getdeb.net/ubuntu xenial-getdeb apps" repo.  Then I installed Filezilla.  On 03/27/2018 that gave me Filezilla 3.21.  I was using sFTP.  It crashed every second and it never successfully transferred any files.  (I never tried old FTP.)

Anyway, I removed the "deb http://archive.getdeb.net/ubuntu xenial-getdeb apps" using the Ubuntu SW Center.  Then removed Filezilla.

sudo apt-get purge filezilla
sudo apt-get autoremove
rm -fr ~/.config/filezilla

Then I reinstalled filezilla from the default deb repo.

sudo apt-get install filezilla

This gave me version 3.15.  It works fine so far.


using tar showing, "No Such file or directory"

You forgot the file extension. The correct command is:

tar zxvf jre-8u151-linux-i586.tar.gz


How to download audio from web page other then youtube from command line?

Download all music files off of a website using wget -

wget -r -l1 -H -nd -A mp3 -e robots=off http://example/url

This will download all files of the type specified after "-A" from a website. Here is a breakdown of the options:

-r turns on recursion and downloads all links on page

-l1 goes only one level of links into the page(this is really important when using -r)

-H spans domains meaning it will download links to sites that don't have the same domain

-nd means put all the downloads in the current directory instead of making all the directories in the path

-A mp3 filters to only download links that are mp3s(this can be a comma separated list of different file formats to search for multiple types)

-e robots=off just means to ignore the robots.txt file which stops programs like wget from crashing the site...

Source


Seahorse shows several suspicious (null) "Personal certificates"

There's an issue #299 for this on the Seahorse issue tracker.
TL;DR: these are distrusted certs marked as such for your protection in your distro's list of root CA's.
Seahorse doesn't handle those well. It's a cosmetic problem, not a security one.
Long Version
Over the years, there have multiple incidents in which CA certs have been  abused (hacked, used irresponsibly, etc'). Since your browser trusts any cert issued by these CAs, these are very serious compromised in terms of security.
In order to protect you from MiTM attack, these certs are included in your distro's list of certificates and explicitly marked as blacklisted/rejected/invalid.
Most distros source the list from the one maintained by Mozilla upstream as part of the nss project.
One example of such a bad cert is the cert(s) issues as part of the Trustwave controversy. Here's the Mozilla issue marking these certs untrusted.
If you look at the mozilla file, you'll see there's an entry called "MITM subCA 1 issued by Trustwave", and it is marked as untrusted.
This and several others example show up as (null) in seahorse because they include enough information for disregarding them, but does not include the actual CA certificate. So, seahorse display them in this strange way.
The 7 entries which correspond to the null certificates are:

"MITM subCA 1 issued by Trustwave"
"MITM subCA 2 issued by Trustwave"
"TURKTRUST Mis-issued Intermediate CA 1"
"TURKTRUST Mis-issued Intermediate CA 2"
"Distrust: O=Egypt Trust, OU=VeriSign Trust Network (cert 1/3)"
"Distrust: O=Egypt Trust, OU=VeriSign Trust Network (cert 2/3)"
"Distrust: O=Egypt Trust, OU=VeriSign Trust Network (cert 3/3)"

You can use your favorite search engine to find out more about the stories behind these (also, DigiNotar and Comodo) and to learn how badly broken the CA trust system actually is.
On Fedora the CA cert list (derived from the mozilla file) lives at /usr/share/pki/ca-trust-source/ca-bundle.trust.p11-kit).
I've tried reporting this to the seahorse developers on their Gitlab, but gave up after 16 captchas, 30 minutes, and one insta-block.
Links:

https://gitlab.gnome.org/GNOME/seahorse/-/issues/299
https://hg.mozilla.org/releases/mozilla-beta/file/tip/security/nss/lib/ckfw/builtins/certdata.txt
https://bugzilla.mozilla.org/show_bug.cgi?id=724929
https://threatpost.com/final-report-diginotar-hack-shows-total-compromise-ca-servers-103112/77170/
https://www.vice.com/en_us/article/78kkwd/a-controversial-surveillance-firm-was-granted-a-powerful-encryption-certifica
https://www.bleepingcomputer.com/news/security/cybersecurity-firm-darkmatter-request-to-be-trusted-root-ca-raises-concerns/
https://security.stackexchange.com/questions/174474/why-is-diginotar-ca-still-in-my-mozilla-firefox


katoolin issue in Ubuntu 18.04 - "/usr/bin/katoolin: No such file or directory"

Open the terminal and type:

git clone https://github.com/LionSec/katoolin.git
sudo cp katoolin/katoolin.py /usr/bin/katoolin
sudo chmod a+x /usr/bin/katoolin
cd /usr/bin/ # change directories to the directory where katoolin is located
sudo ./katoolin # execute the katoolin script


how to connect server using linux terminal?

If you have SSH installed on your server, you can connect very easily. Use the below command skeleton to sign on through a terminal.

ssh username@remotehost.example.com

If you're using SSH keys, be sure that you have them in your ~/.ssh folder. You may need to register them. Otherwise, the system will just ask you for your password upon login.

To get more information about SSH and the command, type man ssh into your terminal.


how to fix "'Error:BrokenCount>0'" after a failed attempt to install virtualbox-5.1

Try opening a terminal and run the following commands:

sudo apt-get update
sudo apt-get -f install

I see this kind of problems most often when my apt databases are pointing to older versions of package files that have since been removed, so cannot be downloaded anymore.

If this is not already the solution then the apt-get -f give you some more output that points into the direction of the cause for this problem.


Running Apache and Tomcat together on different subdomains?

Try:

VirtualHost 'app.example.com:80'

instead of

VirtualHost '*:80'


It depends of your desktop environment. For GUI best variant is vim-gnome.

sudo apt-get install vim-gnome


rkhunter checking for hidden ports skipped

It is disabled by default because it depend on unhide-tcp and this is generally not installed (it is listed when installing rkhunter as optioinal).

sudo rkhunter --enable hidden_ports

will have it scan for hidden ports. It will error out if unhide-tcp is not installed. unhide is in the software center so ...

sudo apt-get install unhide

will install it or see Software Center:


This usually happens in chromium and there is no relation on which websites you visit so I suggest you to make sure you are using the latest version. And if you find a bug refer to http://www.chromium.org/for-testers/bug-reporting-guidelines in order to report it.

It's also useful if you tell us more about your system, which Ubuntu release are you using? And please include the version of your Chromium/Google Chrome.

Complete removal of the software and reinstalling Chromium/Google Chrome with the latest version is recommended and usually solves a lot of issues like this.

Good luck!


Firefox won't integrate with unity launcher

This works for me:

Completely quit Firefox (File | Quit)
Remove your existing Firefox launcher from Unity
Hit Alt+F2, type 'firefox' to filter results, and drag the result into the Unity bar

[edited to replace earlier not-working solution]


According to This forum post the problem could be with failed distro-upgrades. After converting my physical disk to a VM and updating it there it worked with a test script: test.sh

echo run > run.txt

I then put back in my original script and it still didn't work. Taking the advice of Wazoox:

  Yes obviously the "start_bt" script copy files around and run commands from a defined place which isn't / (from which /etc/rc.local is run). You should probably add a line like this : cd /home/[redacted]/Desktop/rtl8723bs_bt/ right after the line echo "Using device $TTY for Bluetooth"

By adding cd /home/[redacted]/Desktop/rtl8723bs_bt/ to the script fixed the problem of it not running. To fix this problem on the physical computer I will need to reinstall Ubuntu, which wasn't a problem for me.


How to install ubuntu in a particular drive?

You can just make some free space for ubuntu in windows and start installing ubuntu.
During the installation select install ubuntu alongside windows

Ubuntu will be installed in the free space created.


If this is a drive that used to be a RAID drive, and you want to use it as a regular drive, you can remove that information with the dmraid you suggest (I checked in the manual man dmraid). See also this link,

Re: Ubuntu/Linux install problems with RAID

So I am rather sure that it will work, but editing this kind of thing is always risky. Installing an operating system is also risky. So there are strong reasons to backup all important data.

It is a good habit to backup your important data regularly. You never know, when your drive will fail or be lost. It is easy to reinstall linux, but the family pictures?


Shim prompts "Verification succeeded" on every startup

I had the same issue and solved this by running mokutil --set-verbosity false.


How could I increase root partition size?

You should backup your important data first
Boot into windows and change locations of some folders such as Downloads, Documents, Music, Videos, Pictures, Desktop folders replacing C by D, so your C (/dev/sda2 partition) will become less used
Reduce C partition size from windows
Prepare Ubuntu installation USB flash drive and boot into it without installing (Try without Ubuntu installing option in previous Ubuntu releases 19.10-)
Run GParted
Do swapoff on linux-swap partition
Extend your Ubuntu's root partition size
Do swapon on linux-swap partition
Apply changes
Reboot

I've not tested it with GPT/EFI disks, so make sure you have backed up your important data or wait for more reliable answer or investigate it yourself


Chrome is the brand product by Google - the base browser AND specific modifications. It generally does a lot of things that are widely considered to be violating the privacy of its users or the fundamental principles of free & open software - hence is not the default choice for Ubuntu users.

Chromium is the software base of all the non-Google-related browser features which is shipped with fewer phone-home features and not many modifications beyond the base browser.

If you wish to find out why they are performing differently, you want to one-by-one disable all Google-specific features in Chrome. You may or may not be able to disable the delinquent, which may be among plugins, codecs, error reporting or search features.

https://chromium.googlesource.com/chromium/src/+/master/docs/chromium_browser_vs_google_chrome.md


How can I change the user during a bash script execution?

sudo -u karthick 'echo \'user_pref("toolkit.networkmanager.disable", true);\' >> ~/.mozilla/firefox/*.default/prefs.js`'

Most likely your problem can be solved more elegantly by some other means. Perhaps if you described that we could help solve the larger problem.


Unbinding USB Interface to use Chrome Web USB API

So basically you have to do this for "8devices".

/sys/bus/usb/drivers/usb_8dev$ echo "1-1:1.0" > unbind

in long:

cd /sys/bus/usb/drivers/usb_8dev
echo "1-1:1.0" > unbind

You will find a file called something similar to "1-1:1.0" in /sys/bus/usb/drivers/usb_8dev so just do a ls to get the correct file and then exchange "1-1:1.0" for this value.

Also don't forget to set sudo chmod -R -v 777 ./ to the driver(ex. usb_8dev) folder.

Also recommended: Disconnect and reconnect ttyUSB0 programmatically in Linux


How to fix terminator not starting anymore?

Check your Python default version with:

python -V

Terminator does not work with Python 3. In my case that was exactly the problem. My default Python command was pointing to version 3 instead of version 2.

You can check your current default python with:

which python

As I already had Python 2.7 installed, as soon as I ran:

sudo ln -sf /usr/bin/python2.7 /usr/bin/python

Terminator started to work again.


That's a messy Unity.

As far as I know, Gnome Shell is by default included in the Ubuntu 11.10 CD so you actually did not need to install it. The excess packages can be automatically cleaned up by executing

sudo apt-get autoclean

and/or

sudo apt-get autoremove


Ubuntu dualboot install not recognizing unallocated space

I was able to solve the problem by going into BIOS and changing my SATA options from RAID to AHCI and afterwards I had to rename some file in my USB installer to get the boot going again. Thanks all for pointing me to the right direction.


Battery draining on Ubuntu touch on BQ M10

I wrote an email to support center of bq for that problem.

They gave me some tips how to calibrate the battery in case that the battery  has to less power:

When the battery is completely empty, load the battery for 8 hours.
Repeat this 3 times.


Install an old OpenShot release in Ubuntu 18.04

You can install whatever version you want by going to the repo you want and finding the needed .deb file.

For example for the OpenShot 1.4.3 you can download it from here

A quick way to install it:

wget https://launchpad.net/openshot/1.4/1.4.3/+download/openshot_1.4.3-1_all.deb -O openshot.deb
sudo dpkg -i openshot.deb

After that, if you have any missing dependencies run

sudo apt-get -f install

To install all the needed ones


how to copy updates from 1 linux box to another using cli remote serial and usb drive

You have the following options for installing packages without an internet connection:

Using Keryx

Keryx is a portable, cross-platform package manager that provides a graphical interface for gathering updates, packages, and dependencies for offline computers.
Using the Synaptic package download script

Synaptic package manager has built-in feature to generate a package download script.
Using apt-offline

apt-offline is an offline text based apt package manager.
Installing downloaded packages

.deb packages (here fits the part from the question relating to the installation of Google Chrome)
.tar.gz and .tar.bz2 packages
.rpm packages

Source: https://help.ubuntu.com/community/InstallingSoftware


After recreating a VM with Ubuntu 16.04.3 LTS, I was able to install paramiko on python3.

Thanks for the help


Ubuntu Live 14.10 Default Password for ubuntu-Desktop-next

(the username is "ubuntu-desktop-next" - without the quotes - , and the password is blank which means you must simply hit the enter key)

Source: http://www.webupd8.org/2014/06/ubuntu-desktop-next-unity8-1410-utopic.html


You could try with booting from a live CD and

sudo apt install smartmontools
sudo smartctl --all /dev/YOUR_DISK

or the GUI version "gsmartcontrol".


Wireless network adapter manufacturers with best Linux compatibility record?

Edimax and Tp-Link are probably the most linux compatible wireless network adapter manufacturers. They are also easy to purchase. For more information about specific models browse this page. When you find something that interests you note the chipset and go to WikiDevi. On the bottom of the main page there are links to specific chipset manufacturers like Ralink, find chipset and on the right there is a link to list of all adapters that use that specific chipset.

Few examples:

TP-LINK TL-WN821N v3 and TP-LINK TL-WN822N v2 on chipset Atheros AR9287+AR7010 2,4GHz supported by driver ath9k_htc
TP-LINK TL-WN721N and TP-LINK TL-WN722N on chipset Atheros AR9271 supported by driver ath9k_htc
TP-LINK TL-WN7200ND, Edimax EW-7711USn and Intellinet Wireless 150N USB Adapter on chipset RALINK RT3070 supported by driver rt2800usb

In case of mini pciE cards you should look for Atheros and Intel products (intellinuxwireless.org).


You can do that in the system configuration under network

system settings > network > proxy

In case you need set by hand your proxy:

If your school uses a auto configuration proxy file:


Open terminal with multiple tabs and execute application which uniquely modifies PS1 variable for each tab

As is the case with most programming, solving the problem was extremely hard. I had to study a bunch about Bash variables, and how to use export and source (or the POSIX dot operator, .), and how bash loads, and what interactive -i bash mode was, etc etc.

I found man bash and man test to also be useful. Here's how to do what I want to do, which is:

Write a script to open 3 tabs.
cd into a different folder in each tab (ie: run a unique command).
get each tab to have a unique title by modifying its local PS1 variable
Ensure each tab stays open after the script is run

1st, add this to the bottom of your ~/.bashrc file:

# Function to allow a user to arbitrarily set the terminal title to anything
# Example: `set-title this is title 1`
set-title() {
    # Set the PS1 title escape sequence; see "Customizing the terminal window title" here:
    # https://wiki.archlinux.org/index.php/Bash/Prompt_customization#Customizing_the_terminal_window_title
    TITLE="\[\e]2;$@\a\]"
    PS1=${PS1_BAK}${TITLE}
}

# Back up original PS1 Prompt 1 string when ~/.bashrc is first sourced upon bash opening
if [[ -z "$PS1_BAK" ]]; then # If length of this str is zero (see `man test`)
    PS1_BAK=$PS1
fi

# Set the title to a user-specified value if and only if TITLE_DEFAULT has been previously set and
# exported by the user. This can be accomplished as follows:
#   export TITLE_DEFAULT="my title"
#   . ~/.bashrc
# Note that sourcing the ~/.bashrc file is done automatically by bash each time you open a new bash
# terminal, so long as it is an interactive (use `bash -i` if calling bash directly) type terminal
if [[ -n "$TITLE_DEFAULT" ]]; then # If length of this is NONzero (see `man test`)
    set-title "$TITLE_DEFAULT"
fi

2nd, create this script to open 3 unique tabs with 3 unique cd commands and 3 unique titles:

open_tabs.sh:

gnome-terminal --tab -- bash -ic "export TITLE_DEFAULT='title 1'; cd ..; exec bash;"
gnome-terminal --tab -- bash -ic "export TITLE_DEFAULT='title 2'; cd ../..; exec bash;"
gnome-terminal --tab -- bash -ic "export TITLE_DEFAULT='title 3'; cd ../../..; exec bash;"

Now open up a terminal and run the open_tabs.sh script:

./open_tabs.sh

Voila! It's magical! These 3 new tabs are now shown at the top of my terminal, and each has done the proper cd command I set, and each has the proper title I set!

This will all be placed into my dotfiles project: https://github.com/ElectricRCAircraftGuy/eRCaGuy_dotfiles.

Full and final solution: see here: Open Terminal with multiple tabs and execute application


Unable to adjust screen brightness on acer extensa 5635z (ubuntu 13.10 )

Try to follow the steps in another askubuntu question, that is :
Brightness issue in a Lenovo ThinkPad Edge LR236W5

or additionally in this page there are three steps you can follow:
https://sites.google.com/site/easylinuxtipsproject/display


What package provides the functionality to suggest which package to install when the user types an unknown command?

command-not-found  is what you are searching for :)


The commands listed here doesn't work on my Ubuntu v17.10 either. If you still wish to use sticky notes, better alternative is to install 'xpad'.

The steps and commands to install xpad are as follows:

Update the packages and repositories:

sudo apt-get update

Install xpad using the command:

sudo apt-get install xpad

Once the processing is done, 'xpad' gets installed successfully on your linux system. To check the same, you can use this command:

sudo dpkg -l xpad

I hope you find 'xpad' as the best alternative to sticky notes.

Regards.


Is it possible to install two kernels and choose one on startup?

You can install both kernels :Generic Ubuntu kernel linux-generic and Low Latency Ubuntu Studio kernel linux-lowlatency. On boot press Shift, to get Grub boot menu, then choose advanced.

If you have installed Ubuntu Studio, install generic kernel:

sudo apt-get install linux-generic

If you have installed Ubuntu Desktop, then convert it to Ubuntu Studio if you like (skip it if you don't want, you can install just the kernel)

sudo apt-get install ubuntustudio-*

Install low latency kernal:

sudo apt-get install linux-lowlatency


Ubuntu runnung painfully slow and hot on laptop

My laptop is almost identical to yours and installing the standard Catalyst drivers did not   fix the problems with the fan and temperatures. (In fact, it caused a new problem of booting into low graphics mode.)

This is because the Catalyst drivers currently have problems with the switchable graphics. The problems with the fan and temperatures were fixed only after following the instructions at: Workaround for Radeon Switchable Graphics in the Ubuntu Community Documentation.

Here are the instructions:

1) First open a terminal window. You can use ctrl + alt +  t

2) Then copy and paste the following commands one at a time into the terminal. Press Enter after each command. To paste into a terminal window, right click and use the paste command from the context menu or click the mouse wheel or middle button. (Note that ctrl +  v will not work.)

sudo apt-get purge fglrx*
sudo add-apt-repository ppa:andrikos/ppa
sudo apt-get update
sudo apt-get -y upgrade
sudo apt-get --reinstall install xserver-xorg-video-intel
sudo apt-get -y install fglrx-updates fglrx-amdcccle-updates
sudo aticonfig --initial -f

3) After the first command, you will be prompted for your password.

4) When you are finished, you will need to reboot.

As an aside, it's apparently common for the brightness controls to not work out of the box with HP DV6. If you find this is the case on your laptop, see:
Brightness not working on HP DV6


How can I organize mixed mp3 files in natty?

You could use something like Banshee to move the MP3's into a consistent folder structure, although you can't do it by genre. You just need to select "copy files to media folders when importing" in the preferences and make sure the directory you are importing from isn't the same as the directory you are importing to.


How do I clean install windows 7 on the "other" partition?

Would you go to this site and follow the instructions on how to get the boot-info URL to post?
https://help.ubuntu.com/community/Boot-Info

I will be able to look at everything I will probably need to see to help you troubleshoot this better.

Thanks,
Chris


How do I prevent ATI Graphics Card from over heating?

There is no way to fix it without installing proprietary drivers.

They can be installed by running in terminal

sudo apt-get install fglrx-updates


How to detect flash process in Google Chrome?

I have found a solution to disable xscreensaver when flash playing in Chrome.

Firstly, disable shockwave flash plugin  at '/opt/google/chrome/PepperFlash/libpepflashplayer.so' in chrome://plugins as follows:

Then the command can detect flash process in chrome:

flash_process=`pgrep -lfc "chrome --type=plugin --plugin-path=/usr/lib/flashplugin-installer/libflashplayer.so"`

I have forked the script from github, and push the new one with Chrome flash detection.  Here is the new script.

Well, the version of my google Chrome:


List of Twitter clients that support Oauth?

If you don't insist on using free software - twhirl and TweetDeck (Adobe AIR apps) support Twitter's OAuth. Note that both of them support multiple accounts and can be used with status.net instances too.


Gnome 14.04 64-bit: HDMI Resolution 1920x1080 but displayed as 640x480

And suddently it hit me, scaling factor! I set my scaling-factor to 1 which it fixes:

gsettings set org.gnome.desktop.interface scaling-factor 1

That fixed it! After that command, only my titles where still too big. But a reboot fixed that too.


Where can I get a self loading CD with Ubuntu OS?

You can get the CD / DVD images here.

Burn it to DVD with your favorite CD Burning program and you have self starting CD / DVD.


Error encountered compiling kernel 2.6.35-25.44

One of the kernel package scripts wasn't working right, so it was trying to copy crypto.master and failing. Below is a patch I made to fix it, although the source package still doesn't include the debian and debian.master folders outside the tar archive like the official Ubuntu kernel source packages.

--- /usr/share/kernel-package/ruleset/targets/source.mk 2009-08-21 09:47:53.000000000 -0400
+++ /usr/share/kernel-package/ruleset/targets/source.mkmod  2011-02-28 14:42:22.000000000 -0500
@@ -64,12 +64,10 @@ debian/stamp/install/$(s_package):
 ####
 ######################################################################
 ifneq ($(strip $(int_follow_symlinks_in_src)),)
-   -tar cfh - $$(echo * | sed -e 's/ debian//g' -e 's/\.deb//g' ) |       \
-   (cd $(SRCDIR); umask 000; tar xpsf -)
+   -(umask 000; find . -mindepth 1 -maxdepth 1 -not -name '*.deb' -not -name 'debian*' -exec cp -Lr {} $(SRCDIR) \;; )
    (cd $(SRCDIR)/include; rm -rf asm ; )
 else
-   -tar cf - $$(echo * | sed -e 's/ debian//g' -e 's/\.deb//g' ) |         \
-   (cd $(SRCDIR); umask 000; tar xspf -)
+   -(umask 000; find . -mindepth 1 -maxdepth 1 -not -name '*.deb' -not -name 'debian*' -exec cp -r {} $(SRCDIR) \;; )
    (cd $(SRCDIR)/include; rm -f asm ; )
 endif
    $(install_file) debian/changelog      $(SRCDIR)/Debian.src.changelog


1 MB "free space" partition is an EFI partition?

Something is confused here. You do not need this "Reserved BIOS Area" Normally. A 1Mb empty space is normally created before or after partitions because of partition padding, it has nothing to do with booting.

Are you using MBR or GPT partition table? It should be GPT.
Is the medium you are trying to install from, UEFI-compatible and is it actually booting in UEFI mode? For example, my Ubuntu USB stick is represented by 2 lines in F8 menu: "Verbatim" and "UEFI Verbatim"


It looks like your initramfs image may be corrupt, or missing. To recreate it, first check your file system for errors, and then run update-initramfs. Note that I've placed comments after each command that you don't need to type, it's just for your information.

boot to the GRUB menu
choose Advanced Options
choose Recovery mode
choose Root access
at the # prompt, type:

sudo fsck -f / # check your file system for errors
sudo mount -o rw,remount / # remount your hard disk read/write mode
sudo update-initramfs -c -k "$(uname -r)" # recreate initramfs image
sudo update-grub # update the grub boot loader
reboot # to reboot the computer

Update #1

boot to the -71 recovery mode, and at the root access # prompt, type:

sudo mount -o rw,remount /
sudo update-initramfs -c -k 4.4.0-72-generic # note the -72
sudo update-grub
reboot # then use the normal Ubuntu boot choice in GRUB

Update #2

boot into whatever recovery mode that you can, prefer -72 or -71
sudo mount -o rw,remount /
ls -al /etc/cryp*

if you see any cryp* files, then cat /etc/cryp{the complete name here}

ls -al /etc/fstab
sudo pico /etc/fstab

arrow keys to move cursor
control-o to save changes
control-x to quit pico

change this line: /dev/mapper/cryptswap1 none swap sw 0 0

to this: #/dev/mapper/cryptswap1 none swap sw 0 0

save and quit pico

reboot (try booting either -72 or -71 kernels)


Is it necessary to install virtualization or VM ware to use Ubuntu on a PC laptop?

Necessary? Certainly not. You can replace your laptop's operating system with Ubuntu and that works well for a lot of people.

But if you're happy with your existing operating system and just want Ubuntu for testing a Rails stack, virtualisation offers a quick, easy and non-permanent method for getting going.

There are even pre-built "virtual appliance" images for testing Ruby which might be the quickest way to get developing but I would strongly advise against pushing these to production.


Need guidance to understand setup of SSHD password / pubkeyauthentication

Questions and Answers:

About the keys: Is there a preferred format? RSA, DSA?

DSA is very old 1024 bit format. 1024 bit keys are not considered secure any more.
ecdsa and ed25519 are more modern key formats. They all have positives and negatives, you have to decide which you want to use.

Preferred bits: 2048? 4096?

Bigger is always better! At least that's my opinion. :-) Note, new formats like ed25519 are not like DSA or RSA. These formats donot accept size option while they are generated. Yet they are considered more secure.

Is there any difference between the private and public keys generated
with "git bash" ssh-key-gen, and PuTTY key generator?

I believe PuTTy stores the keys in a different format, as compared with the Linux openssh client. keys generated with "git bash" may be more compatible with Linux servers.

Is the OpenSSH key format acceptable? Old format or new?

OpenSSH is the standard SSH for Ubuntu. Either old or new format are fine.

I have been confused about using ssh-copy-id to send a public key from
client to server. The server needs to allow password auth in order to
save .ssh/authorized_keys. What's the usual way of getting the public
key into a server if we have password auth turned off ... specifically
because we're trying to implement 100% pubkey auth?

By default Ubuntu ssh servers accept both connections. You may change the sshd_config file to accept only public key once all your users have uploaded their public keys. Or you can ask them to send the public key to you, for example via email, and you can append that key to the authorized_keys file in the server they are allowed to ssh into.

I'd like to get more control over .ssh/known_hosts:
Does this file get updated with every host used for a given SSH pubkey
user?

In this context the host is the ssh server. The known_hosts file resides in the client's computer, which may by PuTTy. For example, say you give me permission to ssh into the server you are setting up. First time I try to login, my computer will note that I have never logged into your computer before and ask me if I trust this host? If I type yes it will add that information into my 'known_host file in my computer.
Now if a hacker somehow manages to divert all request to connect to your computer to another computer. Then when I try to ssh into your computer again, I will be redirected to the hacker's computer. But the information on the known_host file in my computer will not match the hacker's computer. If I am careful, I will see that warning and know something is wrong.

Should we load the file manually to accept connection from a specific
host?

I don't know.

If so, what is the source of that data?

In my computer, the source of that data is all the hosts that I regularly login using ssh. I won't like it if you manually overwrite that file.
See What is actually known hosts? for more.

Ideally I'd like the client application to decide how it's going to
authenticate: If the client is set for pubkey and it has a valid
private key, allow the login. If the client app is set to use a
password, prompt for a password.

This is the default behavior of the ssh server in Ubuntu.

Finally, looking at sshd -T | sort I've been confused when I see a
password prompt in the client while passwordauthentication is "no" in
the server and pubkeyauthentication is "yes". I'm guessing the pubkey
auth is failing and its falling back to password.

Something is missing here. Are you trying to login as root?  Note, you have to restart the sshd service every time you change the sshd_config file. Otherwise the changes you made won't take effect until you restart the computer.
Additional Answers to related questions
See When exactly does SSH-agent use my private_key to connect to a remote server? for my explanation on how private and public keys work.
See Connect two computers with SSH in a home LAN for the basics of ssh setup.
See Key based SSH login that requires both key AND password for double security of both.
Hope this helps


Stuck on Select drive while installing Ubuntu 14.04

Start and continue installation

select something else on this window

now u can see your 500GB and all your drives hard disk
in my case virtual hard disc size is only 8GB capacity it has no partitions in it.

select 30GB drive carefully and delete only that partition by pressing '-'
you can see sizes there so dont worry

now you will see 30 GB  free space and all of your other drives

create new swap area and root partition in free space by selecting freespace and pressing +

first create swap area of size twice of your RAM size (for eg. 1GB
for 512MB)

put remaining size as root partition make sure Ext4 filesystem is selected
in my case (8590-1000=7590MB) but you have to select numbers wrt 30GB and RAM size as I mentioned above.

after that you can see a tick mark on root partition then you an
continue and finish install


How to download songs from Amazon's Cloud Player?

The .amz files downloaded from Amazon's Cloud Drive are actually (subtly) different than the .amz files downloaded from their .mp3 store.  Banshee's Amazon downloader wasn't able to recognize and open these files in Banshee 1.9.6, but this has been fixed.  The fix is in Banshee 2.0, which is in 11.04.


Can I install another linux os without bootloader?

You can let Ubuntu replace grub with Ubuntu's or keep the old one. This is the default, and works well. You will be able to boot the other linux system(s) too.

In BIOS mode, if you want to keep the old one, you should select 'Something else' at the partitioning page, where you can select to install grub to the partition instead of the head of the drive. This does not work in UEFI mode: even if you select correctly, it will use the default settings.

If you keep the old bootloader, you will not see the new system (Ubuntu) until you run

sudo update-grub

in the old system (and reboot).


Finding files deleted from shared partition

Files "deleted" in other partitions should be temporarily be moved in a .Trash-1000 folder within the same partition they were "deleted" from while pending a "definitive deletion"; this is a hidden folder, so try the following:

Open Files
Open the partition in which the file was deleted
Hit Ctrl+h
Open the .Trash-1000 folder and browse its content

The "deleted" file should be somewhere inside this folder.

If it's not, you can try to recover it with testdisk:

Open a Terminal by hitting Ctrl+Alt+t
Install testdisk: sudo apt-get install testdisk
Run testdisk: sudo testdisk
Choose No Log
Select the drive containing the partition from which the file was deleted and choose Proceed
Choose the partition table type
Choose Analyse
Choose Quick Search
Select the partition from which the file was deleted and hit p
Browse both the folder which used to contain the deleted file and the .Trash-1000 folder and see if your file is listed in red; if it is, select it and hit c
Browse to a folder in which you can copy the recovered file and hit C
Quit testdisk

This should recover the deleted file and copy it in the location specified, altough the file might have been overwritten (and be corrupted) since his deletion from the filesystem entries.


There are many reasons why this may be occurring. Being that you said that you use it to boot many distributions it may be that your file system is incorrect, and it is causing you the issue. The other reason why it may not be working is because the USB disk is flat out worn out. Constantly reading and writing over time can lead to the end of the USB's life.


Files are avaliable only when they are executable on Ubuntu 14.04

The directory you copy the files into does NOT have execute persissions.

From that directory do

cd ..
sudo chmod 775 {directoryname}


Can't decrease/increase brightness on Samsung NP300V3A more than 1 step

This question was solved by the OP:

I have found a way to fix it! One must edit /etc/default/grub and add acpi_backlight=vendor to GRUB_CMDLINE_LINUX_DEFAULT.

And then run update-grub. The keys work now!


Could it be possible to make a hot copy of a system?

There are several options that each have tradeoffs.  You can not use dd to clone a filesystem while it is mounted read/write or the clone will end up corrupt since the source is being changed during the copy so the destination will be partially out of date and partially not.  If you really want to be able to use dd to hot copy a partition, you can do so with LVM snapshots.  This requires that you have installed the system using LVM in the first place, but then you can create a snapshot at any time, and since the snapshot is frozen and not mounted, you can safely dd the snapshot, then remove the snapshot.  The other down side to using dd is that it wastes time copying all of the unused space in the volume, and requires the destination be at least as large, even if most of the source is unused.

Rather than use dd, you can simply use traditional backup tools such as tar or dump to backup the snapshot.  This has the advantage of not wasting time copying free space, and can be restored to a smaller partition as long as it has space for the files.  You can also extract only some of the files to do a partial restore.  You also don't have to use LVM with this method: as long as you are reasonably sure that no files are being modified when you make the backup, it is safe to do on a mounted filesystem.  The worst thing that can happen is that an individual file that is modified during the backup will be corrupt, rather than the entire backup being corrupt, as can happen with dd.

As you seem to have realized, after restoring the filesystem, you still need to reinstall grub to get the system to boot.  I'm not sure why you got that error when you tried, but it seems you were using grub-legacy, since grub2 does not have a stage1.


Can't install 19.04 on UEFI laptop (GRUB install error)

Yes. I made it. Basically the disk I was trying to install Ubuntu on needed to be formatted completely so that Ubuntu could create a new partition table as gpt instead of msdos (the drive was used as storage for Win10). Once I did this I was able to install Ubuntu in UEFI mode dual boot.


The "-F" option allows changing Awk's "field separator" character. Awk regards each line of input data as composed of multiple "fields", which are essentially words separated by blank spaces. A blank space (or a tab character) is the default "field separator". In some cases, the input data may be divided by another character, for example, a ":", and it would be nice to be able to tell Awk to use a different field separator. This is what the "-F" option does. To invoke Awk and specify a ":" as the field separator, we write:

awk -F:  ...

In this case, the field separator is a "."


How to prevent certain websites in my browser

One option for you is to block the websites through DNS. On Ubuntu, you may follow the instructions on this answer. You may need to clear your DNS cache from Ubuntu to make sure all DNS query are executed again, thus creating a new cache without the blocked websites. This will not prevent the access to the website itself, but it'll make impossible for your browser to translate www.exemple.com into 67.23.11.1, for instance.

You may apply those rules on your router to further improve the block.


Ubuntu 21.04 Intermittently no Wi-Fi adapter found

It was a hardware hardware issue -- from the evidence so far. I opened up the laptop (after disabling the battery via the bios), disconnected the cables from the wifi adapter, took the adapter out and reconnected everything again. Now the wifi is working and has survived 3 restarts of the system.
Thanks @Akash for pointing me in this direction, I would have looked for software solutions for quite a while longer.
PS: After the reconnection, sudo lshw -C network also shows the adapter again:
  *-network
       description: Wireless interface
       product: Wi-Fi 6 AX200
       vendor: Intel Corporation
       physical id: 0
       bus info: pci@0000:03:00.0
       logical name: wlp3s0
       version: 1a
       serial: a8:7e:ea:ba:87:3b
       width: 64 bits
       clock: 33MHz
       capabilities: pm msi pciexpress msix bus_master cap_list ethernet physical wireless
       configuration: broadcast=yes driver=iwlwifi driverversion=5.11.0-16-generic firmware=59.601f3a66.0 cc-a0-59.ucode ip=192.168.1.102 latency=0 link=yes multicast=yes wireless=IEEE 802.11
       resources: irq:88 memory:fd600000-fd603fff


Ubuntu doesn't "load previously opened applications on start-up" out-of-the-box.

Try this: open the terminal by pressing Ctrl+Alt+T log off and log on again: the terminal doesn't open automatically and if it does on your system, you have an application installed that does that for you. (but I wouldn't know which: check your system settings.

If your question is "How should I add applications to the autostart", then please edit your question to make this clearer and then you have two possibilities:

Using the GUI

Go to the dash, type Startup Applications and any application you want opened at login.

Using the command line

Have a look here for the file locations of these commands.  You can then add those programmatically.


You can reinstall grub and that would fix the problem I guess. http://sosaysharis.wordpress.com/2011/06/29/recovering-grub-after-installing-windows-using-ubuntu/


If I enable ufw, and disable ssh. Is my base install Ubuntu 12.04 safe from the outside world?

You are "safe" a clean Ubuntu installation doesn't have any daemons listening by default.

What you need to do is define safe


unable to boot, gets to initramfs and can't go further

Type the exit command and find out which drive is your / root drive. Then run following commands:

fsck -y /dev/sda1            # (in your case sda1 will be something else)
reboot


Change the parameters to

cache=loose

With one serious comment from the manual page:

  cache=loose can cause data corruption when multiple readers and writers are working on the same files.

cache=

Cache mode. See the section below on CACHE COHERENCY for details. Allowed values are:

    • none: do not cache file data at all

    • strict: follow the CIFS/SMB2 protocol strictly

    • loose: allow loose caching semantics

The default in kernels prior to 3.7 was "loose". As of kernel 3.7 the default is "strict".


Can't find Ubuntu drivers for the HP Envy 4520 printer

I just had to configure Ubuntu 19.10 with HP envy 4520. I had no issues with 18.04, 18.10, and 19.04, as it used to auto-discover both the printer and the scanner over Wi-Fi with no human intervention. However, in 19.10 I had to do it manually.

To add the printer, in Applications, go to Printers and click Add. This should automatically find the printer and add it to the list. You can double check by printing a document. Adding a scanner is a little trickier.

To add the scanner, based on HpAllInOne, I had to run sudo hp-setup. If you get error: hp-setup requires GUI support, you need to run sudo apt-get install python3-pyqt5. Retry sudo hp-setup, and it should open a GUI window1. From there, it wouldn't auto-detect the scanner over Wi-Fi, as it couldn't find any scanners. So, click Back and on the start page, click Advanced. Enter your printer's IP2 and confirm. Now if you go back to Printers utility, you should see your scanner there.

1If that didn't work, refer to the link above. You may need to install python3-pyqt4.

2You can find the IP in at least two ways: (1) if your printer is already detected, go to Printers, click the gear icon, then Printer Details, and you'll see the Address there; (2) in your printer's interface, go to network settings and look for the IP address. It goes without saying, but you should be connected to the same Wi-Fi network!


Example Wordpress content from github missing for juju charm

What it means is that the content you want as YOUR wp-content needs to be able to be found in a publicly accessible repository and this configuration field needs to have the full path to that. The url in question is only an example value.


After much experimentation, I found that putting the display to sleep (e.g. when the screen is turned off after a period of inactivity), waking it, and then restarting pulseaudio makes the sound work until the next reboot.

I'm using the PC as an HTPC that loads kodi at bootup, so I automated this by creating a little script to launch kodi:

#! /bin/sh

xset dpms force off
sleep 1
pulseaudio -k
sleep 1
/usr/bin/kodi -fs

In earlier attempts at fixing the issue I set pulseaudio to never let the sound device sleep (commented out load-module module-suspend-on-idle in /etc/pulse/default.pa), and also set the default sampling rate to 48000 (default-sample-rate = 48000 in /etc/pulse/daemon.conf). Not sure if these settings contributed to the fix, but they are not sufficient on their own.

I also reported a bug against Ubuntu 16.04:

https://bugs.launchpad.net/ubuntu/+source/pulseaudio/+bug/1709708


Control keyboard backlight indicator in Ubuntu 17.10

To avoid the flashing backlight icon, download and install the latest system updates to Ubuntu.

This has now fixed my issue with flashing backlight. As it's not a direct answer to the question -- how to control whether the backlight indicator shows at all -- I'll consider marking another answer correct if one is written. For me, however, this is no longer an issue.


Can I switch between workspaces with middle click?

I think you cannot do it using the mouse middle button.
The mouse middle button in Ubuntu 12.04 is used to switch between open applications.
Applications such as compiz might give you the ability to accomplish this.


It weirdly looks like a "common" problem for Australian users going to the Australian mirrors: https://bugs.launchpad.net/ubuntu/+bug/162865  Per the bug ticket, contact mirrors@ubuntu.com with your traceroutes and debugging.
In the meantime, you can swap out the mirrors in your /etc/apt/sources.list for a non-Australian mirror.


how do I install windows 10 alongside with ubuntu16.04?

Use a bootable Software Like partition wizard or ease us tool ...which can be used to create unallocated disk... (Download.iso and burn into pendrive) after unallocating disk..make a new partition of NTFS format only...again make bootable disk of win 10.iso ,boot and install as regular process..since u r installing win10 after Ubuntu... windows bootloader will overwrite grub and Ubuntu will not be booted...to solve that problem Ubuntu boot-repair program can be used to restore grub and menu will be given to choose in between Ubuntu and window boot loader :) that's it..


Ubuntu wifi roaming problem: how do I set wireless sensitivity on ubuntu?

I think the better way to approach that problem is to run:

nm-tool

Find the MAC address for the access point you want with the highest signal strength. Then Edit Connections in Network manager to tell NM that is the MAC, also known as BSSID, you want. Please see attached. It should then stay on that MAC and not roam to others.


If you installed the Atheros network driver (or any kernel module) from source, then after a kernel upgrade, you must recompile and reinstall the module against the new kernel version.

In your specific case, note that recent 12.10 kernels have got built-in support for various Atheros cards, including the AR8162 which is likely to be in your G580. This card is supported by the alx kernel module.

If you previously had a module installed from source, you may want to attempt to sudo make uninstall it, to (hopefully) undo any blacklistings its installation script may have put in place.


unable to unmount encfs encryped folder in cryptkeeper

My educated guess is that encfs is mounted as a FUSE module. For that Nautilus is a bit confused as on how to unmount it.

Try using fusermount on the commandline:

fusermount -u /path/to/mountpoint

Where /path/to/mountpoint should be /home/xxxxx/Encrypted in your case.

Make sure you've closed all applications (including Nautilus) using that volume before attempting to unmount it.


After update to Ubuntu 17.10, my mounted drive not working

The cifs option for version 1 is vers=1.0, not ver=1.0.


Try this:

@hourly (date; rsync -avc --delete /DirA/ /DirB/) &>  /home/job.txt

Note that I used &> /home/job.txt which redirects both the standard output and the standard error to the log file. That way you will also see any errors produced. Then, I use the date command to generate a timestamp before running the rsync. Placing the commands in parentheses makes the two run in the same subshell and allows the redirection of both commands' output at once.


Surface Book 2 - CPU1 always at 89-91% usage (hot) [18.04]

I just have the exact same issue as you. I install Arch Linux on my Surface Book 2, and kworker/acpi_notify always eat a CPU core.

In your ps -eo pid,comm,%cpu output, kworker also consumes high CPU.

Workaround:

add acpi=off to the kernel parameters. But this may be not acceptable since all acpi functionalities are lost.

Solution:

The issue is the ACPI notify module, use this patched kernel to fix the issue:

  https://github.com/jakeday/linux-surface/

For Ubuntu, you can just use the pre-built kernel directly.

If you want to compile from source on a non-ubuntu system, try this guide or the above Github repo.


Considerations for using `/tmp` directory on multi-user systems

Generally if you wish to store the state for each user the easiest way is to just create a dedicated directory for the application in the users home directory:

CFGDIR="${HOME}/.mycoolapp"
mkdir -p ${CFGDIR}
# read / write files in ${CFGDIR} here..

If you just want a temporary storage for one instance of the script, a good approach is to use mktemp. For example:

TMPDIR="$(mktemp -d)"
# read / write files in ${TMPDIR} here..
rm -rf ${TMPDIR}


Getting screen resolution correct with nvidia drivers

I was in exactly the same situation as the original poster: original UBUNTU 10.04 installation had 1680x1050 resolution; installing the proprietary driver reduced maximum to 1280x1024.

I installed the proprietary driver because I noticed that with the original driver the display was obviously "painting" the display (from top to bottom) on changes instead of "instantaneously" updating the screen image.

Adding the "magic incantation" of

           Option"ModeValidation" "NoMaxPClkCheck"

in the Device section and   PRESTO   all the missing resolutions re-appeared (in the /usr/bin/nvidia-settings configuration program).

source: found on http://fedoraforum.org/forum/printthread.php?t=185230&pp=15&page=3


How to get "Total" Disk read/writes per process in ubuntu from terminal command?

One you can try is iotop

sudo apt update
sudo apt install iotop

Then just run sudo iotop

Total DISK READ :       0.00 B/s | Total DISK WRITE :     894.43 K/s
Actual DISK READ:       0.00 B/s | Actual DISK WRITE:     925.27 K/s
  TID  PRIO  USER     DISK READ  DISK WRITE  SWAPIN     IO>    COMMAND
  497 be/3 root        0.00 B/s   65.54 K/s  0.00 %  1.05 % [jbd2/dm-1-8]
21539 be/4 root        0.00 B/s    0.00 B/s  0.00 %  0.25 % [kworker/~s_unbound]
22873 be/4 terrance    0.00 B/s   15.42 K/s  0.00 %  0.02 % firefox [~T~s #2451]
 9991 be/4 terrance    0.00 B/s  813.47 K/s  0.00 %  0.00 % firefox [DOM Worker]
    1 be/4 root        0.00 B/s    0.00 B/s  0.00 %  0.00 % init splash
    2 be/4 root        0.00 B/s    0.00 B/s  0.00 %  0.00 % [kthreadd]
    3 be/0 root        0.00 B/s    0.00 B/s  0.00 %  0.00 % [rcu_gp]
    4 be/0 root        0.00 B/s    0.00 B/s  0.00 %  0.00 % [rcu_par_gp]
    6 be/0 root        0.00 B/s    0.00 B/s  0.00 %  0.00 % [kworker/~s_highpri]
    8 be/0 root        0.00 B/s    0.00 B/s  0.00 %  0.00 % [mm_percpu_wq]
    9 be/4 root        0.00 B/s    0.00 B/s  0.00 %  0.00 % [ksoftirqd/0]
   10 be/4 root        0.00 B/s    0.00 B/s  0.00 %  0.00 % [rcu_sched]
   11 rt/4 root        0.00 B/s    0.00 B/s  0.00 %  0.00 % [migration/0]
   12 rt/4 root        0.00 B/s    0.00 B/s  0.00 %  0.00 % [idle_inject/0]
   14 be/4 root        0.00 B/s    0.00 B/s  0.00 %  0.00 % [cpuhp/0]
   15 be/4 root        0.00 B/s    0.00 B/s  0.00 %  0.00 % [cpuhp/1]
   16 rt/4 root        0.00 B/s    0.00 B/s  0.00 %  0.00 % [idle_inject/1]
   17 rt/4 root        0.00 B/s    0.00 B/s  0.00 %  0.00 % [migration/1]
   18 be/4 root        0.00 B/s    0.00 B/s  0.00 %  0.00 % [ksoftirqd/1]
   20 be/0 root        0.00 B/s    0.00 B/s  0.00 %  0.00 % [kworker/~s_highpri]
   21 be/4 root        0.00 B/s    0.00 B/s  0.00 %  0.00 % [cpuhp/2]

If you want to see Total since iotop started per process use -a for accumulate:

sudo iotop -a

Total DISK READ :       0.00 B/s | Total DISK WRITE :       0.00 B/s
Actual DISK READ:       0.00 B/s | Actual DISK WRITE:       0.00 B/s
  TID  PRIO  USER     DISK READ  DISK WRITE  SWAPIN     IO>    COMMAND
  464 be/3 root          0.00 B    940.00 K  0.00 %  0.12 % [jbd2/sde1-8]
31167 be/4 root          0.00 B      0.00 B  0.00 %  0.11 % [kworker/~le_power_]
 1689 be/4 root          0.00 B      0.00 B  0.00 %  0.10 % [kworker/~s_unbound]
31999 be/4 terrance      0.00 B      2.72 M  0.00 %  0.02 % firefox [~torage #1]
 1541 be/4 root          0.00 B      0.00 B  0.00 %  0.01 % [kworker/~s_unbound]
32119 be/4 terrance      0.00 B    528.00 K  0.00 %  0.00 % firefox [~torage #9]
32060 be/4 terrance      0.00 B    264.00 K  0.00 %  0.00 % firefox [~torage #4]
32006 be/4 terrance      0.00 B    196.00 K  0.00 %  0.00 % firefox [~torage DB]
32005 be/4 terrance      0.00 B    132.00 K  0.00 %  0.00 % firefox [DOM Worker]
31939 be/4 terrance     12.00 K    820.00 K  0.00 %  0.00 % firefox [Cache2 I/O]
  527 be/3 root          0.00 B     44.00 K  0.00 %  0.00 % systemd-journald
 2764 be/4 mongodb       0.00 B    284.00 K  0.00 %  0.00 % mongod --~onf [ftdc]
31992 be/4 terrance      0.00 B     56.00 K  0.00 %  0.00 % firefox [~taStorage]
32116 be/4 terrance      0.00 B    872.00 K  0.00 %  0.00 % firefox [~torage #8]
    1 be/4 root          0.00 B      0.00 B  0.00 %  0.00 % init nosplash
    2 be/4 root          0.00 B      0.00 B  0.00 %  0.00 % [kthreadd]
    3 be/0 root          0.00 B      0.00 B  0.00 %  0.00 % [rcu_gp]
    4 be/0 root          0.00 B      0.00 B  0.00 %  0.00 % [rcu_par_gp]
    6 be/0 root          0.00 B      0.00 B  0.00 %  0.00 % [kworker/~H-kblockd]
    8 be/0 root          0.00 B      0.00 B  0.00 %  0.00 % [mm_percpu_wq]
    9 be/4 root          0.00 B      0.00 B  0.00 %  0.00 % [ksoftirqd/0]

To get more options check the manpage

man iotop


Headphones Very Quiet with Realtek ALC663 (Intel HDA 82801JI)

Here's the best solution that I've found:

Open terminal and run
alsamixer

You will see the mixer. When you plug the headphones into the laptop note that the "Speaker" column becomes "MM" (muted). Raise the level in that column and you will hear the normal sound level.


Recent notebooks incompatible with ubuntu?

Yes, due to the fact that hardware developers often do not bother themselves with supporting anything but Windows, and often do not release specifications for the hardware, there may be sometimes a lag between a product appearing on the market and support for it added to Linux. The situation improved quite a bit over the last years though, with major hardware developers supporting Linux.

If you want to avoid problems with device support in Ubuntu, you're advised to buy a laptop with Ubuntu pre-installed from one of the manufacturers which sell such machines, or refer to Ubuntu Desktop certified hardware document.

If you have a particular laptop on your mind and it's not in the list of certified hardware - it does not mean it won't work with Ubuntu though, in many cases everything works just fine, but you need to search google to see if there any problems with that particular model.


The errors you see are symptomatic of a missing X authorization file. I've has a similar problem running any GUI application as root in Ubuntu 15.04, and I discovered that it was because Ubuntu was giving the root user an invalid environment variable.

So: from your Oracle user, see if "echo $XAUTHORITY" gives you a path that actually exists. If not, copy .Xauthority from your login directory to your Oracle user, issue "export XAUTHORITY=~/.Xauthority", and try creating your xterm again.

I realize this should be posted as a comment, but I don't have the requisite 50 reputation to do so. It's unfortunate that I have to break the rules to get this information to you.


Nope. Each process will have separate allocated memory.


What commands are needed to install Ubuntu Core?

All of those commands will require admin-rights. Easiest is to do sudo su to get a root console.

Archives like your core .tar.gz (this is oneiric, precise beta is here) are combined in one file (packed) and reduced in size (compressed).

gzip -d ubuntu-core-11.10-core-i386.tar.gz

will uncompress the core to ubuntu-core-11.10-core-i386.tar (no .gz
anymore; one big file).
To partition the device for core it's easiest to use a graphical
tool like gparted. When that's not available. See here. In
a nutshell - assuming you want to partition the device /dev/sda:

fdisk /dev/sda then press n p 1 <Return> <Return> a
1 w (for details please see link).

This creates /dev/sda1 partition.

mkfs.ext4 /dev/sda1

This creates an ext4 filesystem on the new partition. You can of course use mkfs.ext3, mkfs.ext2 as well.

Mount it: mount /dev/sda1 /mnt and go there cd /mnt
tar -xf /path/to/where/you/put/ubuntu-core-11.10-core-i386.tar

will unpack the core (many files).
grub-install --root-directory=/mnt /dev/sda

will install the bootloader (this is of course just one of many options).
cp /etc/resolv.conf /mnt/etc/resolv.conf

will allow network access after chroot-ing (in step 7) by copying the DNS resolver configuration
for f in /sys /proc /dev ; do mount --rbind $f /mnt/$f ; done ; chroot /mnt

will go to a chroot, see Is there an easier way to chroot than bind-mounting? for details about mount rbind
apt-get update && apt-get install linux-{headers,image}-generic

will install kernel ("linux")

Note: it's possible that apt-get update will not work because no network is present.
reboot and you're good to go.

I haven't got a machine to test this so the answer probably won't be complete. I will change my answer should you stumble across problems.


How can I show an icon in the panel if (and while) a certain process is running?

How to show an icon in the panel if a process runs

Based on (and explained in) this answer, we can fairly easily create an indicator, which runs on both Xubuntu and Unity or any other flavour, to show if a process, a script or an application runs or not.

script runs:

script doesn't run:

In the script (indicator) below, I added a thread to detect the process to the indicator:

#!/usr/bin/env python3
import subprocess
import os
import time
import signal
import gi
gi.require_version('Gtk', '3.0')
gi.require_version('AppIndicator3', '0.1')
from gi.repository import Gtk, AppIndicator3, GObject
from threading import Thread

# --- set the path to the script below
script = "/path/to/script.sh"
#---

currpath = os.path.dirname(os.path.realpath(__file__))

def runs(script):
    # function to check if the process runs
    try:
        return subprocess.check_output(["pgrep", "-f", script]).decode("utf-8")
    except subprocess.CalledProcessError:
        pass

class Indicator():
    def __init__(self):
        self.app = 'show_proc'
        iconpath = currpath+"/nocolor.png"
        self.indicator = AppIndicator3.Indicator.new(
            self.app, iconpath,
            AppIndicator3.IndicatorCategory.OTHER)
        self.indicator.set_status(AppIndicator3.IndicatorStatus.ACTIVE)
        self.indicator.set_menu(self.create_menu())

        self.update = Thread(target=self.check_runs)
        # daemonize the thread to make the indicator stopable
        self.update.setDaemon(True)
        self.update.start()

    def check_runs(self):
        # the function (thread), checking for the process to run
        runs1 = ""
        while True:
            time.sleep(1)
            runs2 = runs(script)
            # if there is a change in state, update the icon
            if runs1 != runs2:
                if runs2:
                    # set the icon to show
                    GObject.idle_add(
                        self.indicator.set_icon,
                        currpath+"/green.png",
                        priority=GObject.PRIORITY_DEFAULT
                        )
                else:
                    # set the icon to hide
                    GObject.idle_add(
                        self.indicator.set_icon,
                        currpath+"/nocolor.png",
                        priority=GObject.PRIORITY_DEFAULT
                        )
            runs1 = runs2

    def create_menu(self):
        menu = Gtk.Menu()
        # quit
        item_quit = Gtk.MenuItem('Quit')
        item_quit.connect('activate', self.stop)
        menu.append(item_quit)
        menu.show_all()
        return menu

    def stop(self, source):
        Gtk.main_quit()

Indicator()
GObject.threads_init()
signal.signal(signal.SIGINT, signal.SIG_DFL)
Gtk.main()

How to use

Copy the script below into an empty file, save it as show_proc.py
In the head section of the script, in the line:

# --- set the path to the script below
script = "/path/to/script.sh"
#---

set the path to your script or applications
Copy both icons below (right click -> save as), and save them in one and the same directory as show_proc.py, and exactly named as indicated below

green.png

nocolor.png

  <-- this is a transparent icon, but is is there :). move the cursor over it until the finger appears...
Now test- run show_proc.py by the command:

python3 /path/to/show_proc.py

and start up your script
If all works fine, add the following to sgtartup applications:

/bin/bash -c "sleep 15 && python3 /path/to/show_proc.py"


The protobuf package is called libprotobuf-c1 nowdays. The libev4 is there, if you can not install it, you have generic repository problems.
Your Ubuntu 15.04 is outdated, please upgrade to 15.10. This may be the cause of missing packages.


Can't turn on wifi, Hard-blocked 16.04, HP 14

First go into BIOS and reset it to defaults. If that does not help, then run in terminal

sudo tee /etc/modprobe.d/blacklist-hp.conf <<< "blacklist hp_wmi"

and reboot.


As was already pointed out, bash cannot handle floating point calculation by itself. You're doing a floor-division

(69-64)//11 = 5//11 = 0

Instead use bc

steps=12;ssize=$(bc -l <<< "from=69;to=64;(to - from)/$steps;"); echo $ssize $steps

The option -l will load the mathlib and with it set scale=20 telling bc how many digits after the period to handle. The default is 0, that's why you're also seeing only integer division when invoking bc without -l. Alternatively set scale manually

steps=12;ssize=$(bc <<< "scale=20;from=69;to=64;(to - from)/$steps;"); echo $ssize $steps


What determines default directory permissions?

Yes you are correct - the default permissions are determined by the umask of the creating process. Unfortunately (unlike the SAMBA mount options, which provide separate dmask and fmask), the shell's umask applies to both directories and files:
$ umask 0000
$ mkdir newdir ; touch newfile
$ ls -ld new{dir,file}
drwxrwxrwx 1 steeldriver steeldriver 512 Mar  2 17:22 newdir
-rw-rw-rw- 1 steeldriver steeldriver   0 Mar  2 17:22 newfile

In any case, you can't control the umask of other user's processes (especially not root's).


search for and kill all apt processes:

ps aux | grep -i apt
sudo kill -9 <process id>

you can also type

sudo killall -s9 apt apt-get


If you are talking about updating software then I recommend just opening a terminal and running sudo apt-get upgrade to update all packages. If you are talking about installing something I would recommend finding the package name and typing sudo apt-get install [package name] as I have found the terminal to be a lot more reliable and it provides and installation log should something hang.


How does the backup-button works and how can I use this under Ubuntu?

I have a drive with a button like this but due to my transient state the drive is in storage (I feel like there's a joke to be had there) and I have never researched the button before. What I'm about to say could be completely incorrect.

If I were to guess what was going on, I'd say the drive consisted of three things:

A USB hub controller
A USB storage controller
A simple USB HID device

You can check this with lsusb or sudo lshw | less.

The hub and storage device will be as standard as possible so that anything can use them. The HID button might work in Linux without a driver but it won't be connected up to any known event.  If it does automatically work, it should have registered a device in /dev/input/. If that's a case, it's fairly simple to hook an event around it.

If there isn't a device registered automatically, it might be a very non-standard USB device that needs a custom driver for itself. I can't help you past this stage.

In Windows, you would install some software that would likely include the driver for the HID device, add a listener and tie the lot together.


how to uninstal a program when graphical mode can not load

GRUB (GRand Unified Bootloader) is the bootloader used by Ubuntu. It's not the safe mode, but you can use it to enter Ubuntu's recovery mode.

To access the recovery root shell, press Ctrl+Alt+Del during Ubuntu boot. It will reboot to the GRUB menu. Now follow these steps:

Select Ubuntu ... (Advanced Options)
Select the root entry (root console for recovery)
Remount the system partition with R/W permission: mount -o remount rw /
Now remove/purge yourprogram: apt-get purge yourprogram && apt-get autoremove
Reboot: reboot