Microphone - external sound card noise suppression

In my case the headphone appears in the port list for "Built-in Analogue Stereo" itself and I can choose it in pavucontrol to let echo-cancel use it.

For your case I think you may need to explicitly point echo-cancel to the external source. You can specify the "source_master" argument to the module as per the documentation here.

So find out the name of the external source pactl list sources | less, then search for required external device e.g. "Audio Adapter Analog Mono" as above (there might be entries for monitor devices for that as the description will show so skip those; the real device will have "alsa_input." prefix in name). Get the name of the required external device and add to the line in /etc/pulse/default.pa:

load-module module-echo-cancel source_name=echosource aec_method=webrtc source_master=alsa_input.pci-0000_00_1b.0.analog-stereo

(change the name in source_master as found before). I couldn't find a way to change this to internal mic or back to external mic dynamically other than unloading+loading module again using pactl/pacmd.

BTW, in my case the noise cancellation takes a few seconds to take affect and first few seconds in Skype have noise which smoothens out quickly.


My guess is that you have a bad burn or the downloaded iso is corrupt. Check the md5sum of the iso from the link I gave you and if it looks good try another burn.

FWIW you need to "burn" this iso image onto a CD and not copy it.

See: https://help.ubuntu.com/community/BurningIsoHowto

There are reports of similar boot errors with hardware problems (faulty ram , faulty power supply) but I am assuming your computer "works"


Durning make，I meet the same problem as yours at the point of 48%.
You need to change
Molsketch-0.2.0-Source/libmolsketch/src/stereocenteritem.cpp line  66 as: std::vector<OpenBabel::OBStereoUnit> units = FindStereogenicUnits(obmol, symmetry_classes);
When compile reach 90%,I meet another problem：

  Molsketch-0.2.0-Source/molsketch/src/mainwindow.cpp:22:28: fatal
  error: QAssistantClient: No such file or directory

My Qt version is 4.8.5.Qt remove QAssistantClient after 4.7+.My solution is,comment every line related to QAssistantClient in mainwindow.cpp and mainwindow.h.


If you haven't re-used the disk space, you should be able to recover the partition with TestDisk. After recovering the partition in this way, the NVRAM-based boot manager references might or might not work any more, so you may need to recover the system to bootability in one way or another. One way would be to use my rEFInd boot manager on a USB flash drive or CD-R to do a one-time boot and then create a new boot entry with efibootmgr. The command would be something like this:

sudo efibootmgr -c -d /dev/sda -p 1 -l \\EFI\\ubuntu\\shimx64.efi -L ubuntu

This creates a new boot entry for the EFI/ubuntu/shimx64.efi boot loader file on /dev/sda1. Change the -d, -p, and -l options as necessary for your system.

A caveat: The rEFInd USB flash drive and CD-R images I provide do not support Secure Boot. If it's enabled, you'll need to either disable it or jump through some hoops to get rEFInd to work with Secure Boot active. You can temporarily disable Secure Boot and then re-enable it later, if you like.

If you have overwritten the part of the disk that used to hold the ESP, your task is harder. You can still do a one-time boot using rEFInd, but you'll then need to create a new ESP and populate it with boot loaders for both Ubuntu (probably GRUB, but you could use rEFInd or something else) and Windows. If you have a backup of the ESP, restoring it should work. If not, you could use Boot Repair to install a fresh GRUB or install rEFInd from its Debian package or PPA. For Windows boot recovery, you'll have to ask about this on a Windows forum. If possible, do the Windows recovery first, since Windows will set its boot loader as the default, and it won't provide an option to chainload to Ubuntu. GRUB and rEFInd, by contrast, both provide options to boot either Ubuntu or Windows. (Or they should; sometimes this doesn't work correctly.)


How can I change the icon of a fogger app

Well you could open the Fogger-App with an editor like Scratch and change the icon. This should look like:

[Desktop Entry]
Name=Google Music
Comment=Google Music
Categories=Network;WebBrowser;
Exec=/opt/extras.ubuntu.com/fogger/bin/fogger 2c9d692a576395c5d7a2c91b5a101d09
TryExec=/opt/extras.ubuntu.com/fogger/bin/fogger
Icon=/usr/share/icons/eNumix-uTouch/apps/48/google-musicmanager.svg
Terminal=false
Type=Application
StartupNotify=true
StartupWMClass=fogapp-2c9d692a576395c5d7a2c91b5a101d09
Keywords=fogger;fogapp;

You will have to change two app files one for the Launcher and one for fogger.

I use Slingshot on elementary OS Luna and had to changes these app files:

Fogger:
    /home/USERNAME/.local/share/fogapps/

Slingshot:
    /home/USERNAME/.local/share/applications


You are probably talking about /etc/gnome/defaults.list which has nothing to do with monitors as far as I know.

You should be able to find /etc/gnome/defaults.list.dpkg-old or /etc/gnome/defaults.list.dpkg-new depending on which file you choose to install during upgrade.

You can also search for the package that contains the particular file:

$ dpkg  --search /etc/gnome/defaults.list
desktop-file-utils: /etc/gnome/defaults.list

Reinstalling should also work:

$ sudo apt-get install --reinstall desktop-file-utils

How can I restore configuration files?

As always, it's important that you know the exact error message. The system keeps logs for you: Can I look at the upgrade log after a distribution upgrade?


What's the difference between 'sudo [command]' and 'sudo sh [command]?

If the file is not marked as executable you need to call a command shell interpreter to execute it.

Examples:

sudo sh foo will open foo with sh using sudo privileges.
sudo bash foo will open foo with bash using sudo privileges.
sh foo will open foo with sh using your user's privileges.
bash foo will open foo with bash using your user's privileges.

If you mark a file as executable you just need to call it with ./foo and because it is marked as such it will be read with the defined command shell interpreter and executed without the need to define one.

ls -F will list files and mark executables with *.

To enable the execute bit on a file (and make it executable as such) use the command chmod +x foo.

In your case to make the file you are using executable you would then use the command

chmod +x VMware-Workstation-9.0.1-894247.x86_64.bundle

and then you will be able to run it with either

sudo sh ./VMware-Workstation-9.0.1-894247.x86_64.bundle or just by typing sudo ./VMware-Workstation-9.0.1-894247.x86_64.bundle.


Find and download a package without sudo using aptitude

As mentioned in one of the comments, use apt-get just to download, then dpkg -i to install.

mkdir $HOME/.local
apt-get download <package_name>
dpkg -i --force-not-root --root=$HOME/.local <package_name.deb>

Note: what's nice is that apt-get automatically picks the package that fits your Ubuntu distribution and your architecture.


There are at least a hundred thousand million different ways of approaching this but here are the top contenders:

The Bash for loop

for f in ./*.doc; do
    # do some stuff here with "$f"
    # remember to quote it or spaces may misbehave
done

Using find

The find command has a lovely little exec command that's great for running things (with some caveats). Find is better than basic globbing because you can really filter down on the files you're selecting. Be careful of the odd syntax.

find . -iname '*.doc' -exec echo "File is {}" \;

Note that find is recursive so you might want to use -maxdepth 1 to keep find in current working directory. -type f can be used to filter out regular files.

If we're just renaming doc to txt...

The rename command is sed-like in searching. Obviously this won't do anything to convert the format.

rename 's/doc$/txt/' *.doc


nvidia-prime extended desktop stopped working

The compiz fix suggested here solved the problem for me.

Francisco Gouveia (fgouveia87) wrote on 2015-03-10:
After days lost with replacing NVidia drivers and manually editing xorg.conf
file, I finally found this!
Rockwalrus (rockwalrus) solution works!
On CompizConfig Settings Manager, go to "General Options", then
"Display Settings" and do the following:

Uncheck "Deteck Outputs"
In the Outputs array, set the resolutions of each of your screens. The numbers after the resolution "1920x1080+0+0" are the offset. It's
important to add this offset according to your needs. I have two full
HD screens, so I added the following configuration: 1920x1080+0+0
1920x1080+1920+0

The second output has an offset of 1920, because it is on the right
side of the first output, which has a width of 1920.


How to resolve a request on /folder to a separate documentroot on Apache 2.4 and pass php to two fpm pools

According to "Question 1)":

you should add an alias:

Alias /site2 /var/www/site2
<Directory /var/www/site2>
    Require all granted
    AllowOverride all
</Directory>

The DirectoryIndex directive reads the statements as 'absolute' filenames. I mean with this syntax:

DirectoryIndex /index.html index.html

DirectoryIndex will check if index.html, located in DocumentRoot=/, exists and will display it if yes, and will ignore next statements. So if this record (/index.html) is not intended it is wrong. Some examples here.


Is it possible to install Ubuntu on a Mainboard Asus P8H67-M with UEFI BIOS?

As far as I can tell it should have the same BIOS/UEFI as my ASUS P8Z68-V and that works just fine.


How do I install Ubuntu on an HP Touchsmart 600?

Try using nomodeset during the install. When you pop in the cd, try pressing F6 and select nomodset or press F4. If that doesn't work, try using unetbootin and install via USB. A third option would be the text installer.


Discover how your system sees those keys, using the command xev and pressing the keys whose id you want to discover.After entering the xev just press page up and then press alt+t then you will get the following results. Then use the key code you got on pressing alt+t keys in the command at the end. that's all it will be done. I did this on my laptop and got the below results and so i gave it for reference only. You have to perform action to get your own result as these results vary with computer.

Pressing Up produces keycode 111, assigned to action Up:

KeyPress event, serial 34, synthetic NO, window 0x3a00001,
root 0xa5, subw 0x0, time 13739005, (165,-16), root(170,32),
state 0x0, keycode 111 (keysym 0xff52, Up), same_screen YES,
XLookupString gives 0 bytes:
XmbLookupString gives 0 bytes:
XFilterEvent returns: False

Pressing Pg Up key gives the following:

KeyPress event, serial 32, synthetic NO, window 0x2400001,
root 0xc3, subw 0x0, time 13714833, (61,151), root:(63,236),
state 0x10, keycode 112 (keysym 0xff55, Prior), same_screen YES,
XLookupString gives 0 bytes:
XmbLookupString gives 0 bytes:
XFilterEvent returns: False

Once you know the keycode of the keys you would like to use, and the name of the actions you want to perform, you can assign the desired actions to the chosen keys.
The following four commands will produce the desired change, valid only for the present X session:

xmodmap -e "keycode 112 = Up"

To get these changes for every session, after issuing the commands above, create a file called .Xmodmap (or whatever), with the following command:

xmodmap -pke > .Xmodmap

Then, create a file called .xinitrc in your home directory, containing just the following line:

xmodmap .Xmodmap

Enjoy!

Refer to the site for any doubts: http://wiki.linuxquestions.org/wiki/...txkbmap_Method


Well, I think you can use this link

Here you can see how to download and install the driver... and I think this is the link in the epson page
where you can download the driver...

Hope it helps...


Check if NTP Client Daemon is Working properly Using NTPDC

Type ntpdc -c peers into terminal. Or ntpdc -p should do it as well.

Both commands effectively print out a list of the peers known to the server as well as a summary of their state.

Observe output and confirm whether or not the daemon is working properly.


Terminal improper output, unprintable character

After a brief conversation in the comments...

we checked the output of the date command
we checked the date format configuration in the /etc/vnstat.conf file
we checked the Terminal app preferences in the encoding tab
we checked the language settings in System Settings/Language Support

It was found that by setting the Language Support regional format (from India) to English (US) and applying it system wide, fixed the problem with vnstat displaying odd characters in the date field.

A log out may be necessary for the changes to take effect. :)


Can I write a bash script and add it into right-click list of the graphical file explorer?

Yes you can. The file manager Files (nautilus) has a feature "nautilus scripts". When this folder exists and contains executable scripts, a "Scripts" entry will appear in the right-click menu that will include these scripts. See the Ubuntu Community Help Wiki to see how you can use predefined variables containing the selected file names, the current directory, etc.


Ubuntu boot stuck with after installing amd gpu pro graphics drivers showing no gui

Please do check if you've downloaded the correct driver. It should be for Ubuntu 18.04 and not for 20.04. Secondly, try to load Ubuntu in a recovery mode. To boot Ubuntu in recovery mode you either have to hold the shift key or press escape key. It will show you a black screen with option from there choose "Ubuntu Advance Option/Ubuntu Recovery mode". Then you've select start Ubuntu to launch Ubuntu with minimal driver setup. After login try the following command.
sudo nano /etc/default/grub

Then edit the below line
GRUB_CMDLINE_LINUX_DEFAULT="quiet splash"

To:
GRUB_CMDLINE_LINUX_DEFAULT="quiet splash amdgpu.dc=0"

Then press "ctrl+x" and then press "Y".

sudo update-grub
Then reboot.


Brightness is reset to maximum on every restart

You could try adding a line to /etc/rc.local that will set the desired brightness level. To edit the file, run

sudo -H gedit /etc/rc.local

and add the following

echo X > /sys/class/backlight/intel_backlight/brightness

so that the end result looks like this

#!/bin/sh -e
#
# rc.local
#
# This script is executed at the end of each multiuser runlevel.
# Make sure that the script will "exit 0" on success or any other
# value on error.
#
# In order to enable or disable this script just change the execution
# bits.
#
# By default this script does nothing.

echo X > /sys/class/backlight/intel_backlight/brightness

exit 0

Substitute X by the desired brightness level.

In case /etc/rc.local doesn't exist, as is the case with new Ubuntu releases, you'll need to create it, and make eecutable with the following commands:

printf '%s\n' '#!/bin/bash' 'exit 0' | sudo tee -a /etc/rc.local
sudo chmod +x /etc/rc.local

PS: Alternatively, there may be /sys/class/backlight/acpi_video0/brightness instead of the above. Brightness levels vary wildly, and may range from 0 to 10 or to 1000. To find the maximum value, try

cat /sys/class/backlight/acpi_video0/max_brightness
or
cat /sys/class/backlight/intel_backlight/max_brightness


Can't boot Ubuntu 17.10: [Firmware Bug]: ACPI region does not cover the entire command/response buffer

Seems to be a BIOS bug.

Try to switch off TPM and ACPI in the BIOS.


ubuntu 16.04.5 boot fail, what shoud I do next?

It looks most like an unattended update gone wrong. Try those steps first.

 sudo dpkg --configure -a


I have got the same Problem. It occurred after clean install Ubuntu 16.04. I have looked several hours for any information and tried several things. Nothing helped. It was really annoying. In Ubuntu 15.10 the shutdown was: switch and off in less than 1 sec. Now it took at least 1,30 sec. Finally I figured out, after lots of troubleshooting, that (after disable the Ubuntu boot splash screen) a certain stop-job was running that made the shutdown slow. (Thanks to Alex!) Then I got this error report: "a stop job is running for make remote cups printers available locally" Then I tried this:

sudo systemctl stop cups-browsed.service
sudo systemctl disable cups-browsed.service

and to verify:

sudo systemctl status cups-browsed
sudo systemctl is-enabled cups-browsed

and it finally worked! Shutdown was now as good and fast as ever. (you can find this troubleshooting on: "The Annoying Cups Browsed" at the ec-cwang´s Blog!)

This might be important for those this solution is not helpful: How to find out your running stop jobs, just look up: "How do I disable the boot splash screen" on Ask Ubuntu. Then, if you start Ubuntu you get the typical Linux running command signs. If you shut Ubuntu down, mention the output. It shows you at the end what kind of stop job slows down your shutdown procedure.


problem to use plasma-nm on xubuntu 16.04 (Solved)

The answer was simple . i didn't need to install any thing to create an acces point supported by android phones . i used the stock network to create hotspot  and it's working . so it seems it's now embedded in the system and no need to install another package


If you are not behind a router, you can find it out using ifconfig.

If you are behind a router, then your computer will not know about the public IP address as the router does a network address translation.  You could ask some website what your public IP address is using curl or wget and extract the information you need from it:

curl -s https://checkip.dyndns.org | sed -e 's/.*Current IP Address: //' -e 's/<.*$//'

or shorter

curl https://ipinfo.io/ip


The solution is here (in portuguese)

To install according to Arnet never works on linux.

Have to install manually.


I recommend using Gparted its very easy to use and one of the best partition manager out there , yeah even comparing windows paid apps here is the LINK to live cd or install locally using sudo ap-get install gparted  and for partition recovery there is a awesome free tool called testdisk and photorec utility for data recovery,it gets installed with testdisk metapackage

to install testdisk

sudo apt-get install testdisk

LINK for testdisk usage

LINK for photorec usage


According to this answer, gksu is now deprecated. And according to a couple of Ubuntu bug reports, it appears this is the case.
You can just use sudo to open vmware player as root:
% sudo -i vmplayer &

To open vmware workstation as root:
% sudo -i vmware &

Another options is to just switch to su:
% sudo su
% vmplayer &

Or workstation:
% sudo su
% vmware &


18.04 with VirtualBox 6: Need Help installing alfa awus036ach USB attached WiFi

You could install the latest drivers from this GitHub repo: https://github.com/aircrack-ng/rtl8812au.git

As per the repo, this is how you can install the drivers using DKMS method:

sudo apt update
sudo apt install dkms
git clone -b v5.6.4.2 https://github.com/aircrack-ng/rtl8812au.git
cd rtl8812au
sudo ./dkms-install.sh

Your USB WiFi adapter should be working now.


The same problem I have faced.In my case I Restarted my client system(windows 10) and then tried to access share,it worked for me.I think it will work for you.


Wallpapers are merged with multiple images after suspend

This sounds like a bug. When this happens, try pressing Alt+F2, type r and press enter. This will re-initiate your GNOME session without logging out or closing any applications.


Can not upgrade Ubuntu server to 13.04 using command line

The -d switch is not required in this case. At the time of the question, 13.04 was stable not development. The -d switch indicates to do-release-upgrade to install the latest development version, but at the time no distribution was on development. A normal sudo do-release-upgrade will upgrade your system.


Does the /dev/null file actually have a fixed size?

/dev/null is not really a file. It's a character device!

$ ls -l /dev/null
crw-rw-rw- 1 root root 1, 3 Apr 10 09:53 /dev/null

The first letter c of the permissions string (crw-rw-rw-) indicates this. For regular files, it would be a - instead.

So in easy words: /dev/null is not a file but a virtual device mapped to this path in the file system, which has the only purpose to swallow and vanish data - like a black hole.
It can also be used as input though, then it acts like an empty file (size 0) and immediately returns an EOF (End Of File).

Therefore you can not really say that /dev/null has a specific file size, as it's not a regular file on any storage medium.


pidof <insert process name>

ex:

user@localhost:~$ pidof firefox
31838


How can I prevent someone from resetting my password with a Live CD?

A quick and easy way to do this is to disable booting from CDs and USB sticks in your BIOS and set a BIOS password.

According to this wiki page:

  Placing passwords or locking menu items (in the Grub configuration files) does not prevent a user from booting manually using commands entered at the grub command-line.

However there's nothing stopping someone from just stealing your hard drive and mounting it on another machine, or resetting your BIOS by removing the battery, or one of the other methods that an attacker can use when they have physical access to your machine.

A better way would be to encrypt your drive, you can either do this by encrypting your home directory, or encrypting the entire disk:

How do I encrypt my home partition?
https://help.ubuntu.com/community/FullDiskEncryptionHowto


how do I restore my account after upgrade to 11.10

It sounds like unity may have got a bit broken on upgrade. You can try fixing it by opening a terminal and typing:

unity --reset

If it doesn't work, please add the output of that command to your question.

Also it might be worth uninstalling the nautilus-open-terminal package if you had it installed - this caused compiz crashes (launchpad bug) which might lead to your problems. The fix is currently in the oneiric-proposed repository, and should be generally available soon, but not quite yet.

Alternatively, this answer suggests:

  I found the workaround here:

sudo rm /usr/share/GConf/gsettings/pythonconsole.convert
gsettings-data-convert
gnome-settings-daemon

  Then, to solve definitely at every login, I had to create a launcher
  to gnome-settings-daemon in my home folder and add it to my startup
  applications.


You can create multi boot usb with multisystem: MultiSystem – Create a MultiBoot USB from Linux
Download the script, your favourite linux iso and using the multisystem transfer the isos to the usb. It will create a separate Grub menu on the USB with multiple choices.

It can boot Windows iso also.
When you have a dos or windows iso, you can find the menu entry under GrubforDOS.


Gnome shell hangs if network disconnect with cifs mount on

What you are describing is a use case for a systemd automount.

You accomplish that by adding an entry into /etc/fstab that in your case would look something like this:

//network-adr/logs /home/bruno/mylocaldir/log cifs username=me,password=pass,noauto,x-systemd.automount,x-systemd.idle-timeout=10 0 0

Then make systemd happy by running:

sudo systemctl daemon-reload
sudo systemctl restart remote-fs.target

noauto = prevents the share from mounting at boot.

x-systemd.automount = will mount the share when the mount point is accessed - on demand

x-systemd.idle-timeout = sets the time in seconds when the system will automatically unmount the share when it detects no activity.

It is all fairly seamless to the user. Click on the mount point and it mounts without user intervention. If it's not used in 10 seconds ( or 20, 30, ..etc.. ) it will unmount without user intervention.

Anything will trigger the automount: You accessing the mount point in your file manager, some script you may create that accesses the mount point or subfolder of that mount point, etc..


Does the Sleep and Charge feature of USB 3.0 in Samsung 5 Laptop work with Ubuntu 12.10?

I have finally tried to boot ubuntu 12.10 alongside windows 8. Sleep and Charge is BIOS Feature Hence Irrespective of the OS Installed, it would work Fine. Confirmed working fine on Samsung Series 5 NP550PC S03IN.


Removing Skype 4.2 (from the Ubuntu Software Center) and installing the latest version (4.3) from skype.com (I selected Ubuntu 12.04 as distribution) worked for me

alex


Using revtex on Ubuntu 14.04 (texlive-publishers installed)

It works for me (Ubuntu 16.04, TeXLive 2015) if I change the snippet into:

\documentclass{revtex4-1}
\begin{document}
\end{document}

It outputs a warning:

Class revtex4 Warning: No Society specified, using generic APS style.

So probably it needs some options to tailor it for the journal. You can see the documentation with

texdoc revtex

(if texdoc doesn't work, search for a file named aipguide4-1.pdfin your system)

So for example for Journal of Applied Physics you should use:

\documentclass[aip,jap]{revtex4-1}


Installing Ubuntu Server on separate partition

After some looking around I came to the conclusion to run a virtual instance via VirtualBox and have it running in the background so that I can access it via the server itself or externally if needed. Until, or if, Windows gets support to be able to look into Linux files without complications, this will work


Windows 8 laptop keeps alternating between the Windows 8 bootloader and Grub2

You should be able to go into the BIOS and select the Ubuntu partition as your boot partition:

You can do this. by hitting one of the f keys (I never remember which - I think each PC is different anyway) as your computer is restarting. You just select your primary boot partition as the one you want.


Where is the ISO file to burn image to CD

I'm afraid you will have to download the entire file ; most CD burner programs will not burn a disk from a file on the internet, and even if they would, unless your connection is very fast, and very stable, you'd probably end up with a bad CD anyway.

Other ways to get a bootable copy of Ubuntu would include purchasing the 8GB Mini USB with Ubuntu Precise (sadly, not available yet).


you should consider installing jupiter

you can select power modes with it, its very easy to controll, and I just set it to power on command, you wont notice that your laptop is on, until you start using heavy apps

open terminal and do this.

add the repository

sudo add-apt-repository ppa:webupd8team/jupiter

update

sudo apt-get update

install jupiter

sudo apt-get install jupiter

and to other people reading this and are using an Asus EEPC netbook, install this asswell

sudo apt-get install jupiter-support-eee

Have a nice day :)


My laptop has no operating system is it possible to download Ubuntu into my phone and transfer it to my laptop?

If you are using an Android phone, there is an app on the Google Play Store called DriveDroid that claims you can use your phone as a live USB and allows you to boot your PC from ISO/IMG files stored on your phone. This application requires root. I have no personal experience with this, but it could be worth a shot.


I am not an expert, but did you try this?

echo "options snd-hda-intel model=generic" | sudo tee -a /etc/modprobe.d/alsa-base.conf

https://www.linuxuprising.com/2018/06/fix-no-sound-dummy-output-issue-in.html

This has fixed a similar problem on my computer (Ubuntu 18.04).
Best regards.


You should not use the dpkg command directly to manage packages in general, but should use the apt-get command instead. It is generally safe for the ubuntu-desktop package to be removed, as it is a meta-package that only depends on other packages. Nothing should be depending on it.

Simply doing sudo apt-get remove --purge evince will show you what packages exactly will need to be removed as a result of evince's removal. You can accept or deny the transaction. If you accept, then evince and ubuntu-desktop will both be purged, as will any other packages which apt-get lists as needing removal when you run the command.


Just install version 12.0 instead of 12.1. It is (still) available on Citrix site (http://www.citrix.com/site/SS/downloads/details.asp?downloadId=2316611&productId=1689163) and works just fine.

Or you can extract the package:

dpkg -x icaclient_12.1.0_amd64.deb /some/folder
mkdir /some/folder/DEBIAN
dpkg -e icaclient_12.1.0_amd64.deb /some/folder/DEBIAN
vi /some/folder/DEBIAN/postinst

In line 2648, change the text between double quotes ("i[0-9]86") for "[0-9,x]86" an then run the following:

dpkg -b /some/folder

It will correct the bug in the postinst script that tries to figure out the architecture of your processor. The 'dpkg -b /some/folder' will then recompile (build) the package. All you need now is to install the recompiled package, which will be named after the folder you used to extract it. I just don't know why Citrix haven't done it yet, for it is a relatively old bug, and with a very simple solution.

If you are not interested in doing the dirty job, just download the version I corrected from https://dl.dropbox.com/u/3207848/icaclient_12.1.0_amd64.deb.

Hope I helped!


"bash: ./eclipse: cannot execute binary file" when trying to install Eclipse

I found my problem.
I had downloaded the 64-bit version but my system was 32-bit. When I tried the 32-bit version of Eclipse, extracted it and in the eclipse folder wrote in terminal
./eclipse

it worked.


How do I revert back my changes in compiz opacity settings?

I am sorry for asking such a simple question. For noobs like me here how I fixed it.
I navigated to user directory from another user session and renamed compizconfig

mv ~/.config/compiz-1/compizconfig  ~/.config/compiz-1/compizconfig.old

and when I logged into my current session windows can be seen.


device = next(Path("/sys/class/rc/").glob("rc*/input*/event*/"),None)
if device == None:
    devpath = None
else:
    devpath = f"/dev/input/{device.name}"


Why is System76 not mentioned on the Ubuntu certified hardware partners page?

We don't submit our Computers to Canonical for Validation testing for a number of reasons.

We have a very rapid hardware development cycle, and submitting to Canonical for validation would slow that testing and development down and reduce our ability to launch new product quickly.
We do a large suite of in-house testing to ensure that Ubuntu runs flawlessly out of the box on all of our computers. This that instead of needing a validation to tell you it works, simply buying System76 from the start guarantees compatibility with Ubuntu, since that's all we work with.


Setting up Postfix with amavisd-new, spamassassin, clamav, and SPF checking?

That guide is all about filtering spam out of your incoming mail. There's not really any setup required on your system apart from saying you'd like to check SPF and DKIM.

If you invoke that checking, then when your server gets an email from IP address 123.123.456.456 claiming to be from fred@example.com, it will look for a TXT record in the DNS entry for example.com to see if that IP address is listed as a valid source of mail for example.com

DKIM just adds some more complexity on top of this


How do I tell the system that the service has started?

from systemd.daemon import notify, Notification

# Send READY=1
notify(Notification.READY)


Booting Stuck at "Loading Initial Ram Disk..."

It looks like your updated kernel is causing the problems. Not sure how, but you can purge it and use your older kernel.


I want to learn SQL and PL/SQ, what database should I use?

PL/SQL is a procedural language used in Oracle: http://en.wikipedia.org/wiki/PL/SQL

So, if you want to learn PL/SQL, then Oracle is your only choice.

If you want to learn SQL in general, then PostgreSQL, MySQL or even SQLite are quite suitable for the task.


Check the value of the list_visible parameter in .purple/prefs.xml, if it is 0, close pidgin, edit and change it to 1, then restart pidgin.

<pref name='list_visible' type='bool' value='1'/>

You can also try the same with 'blist_autohide'

<pref name='blist_autohide' type='bool' value='1'/>


Can't install Skype from partner repository

Skype isn't available from the Ubuntu repositories. To install it on a 64-bit system, open a terminal (press Ctrl+Alt+T) and run:

wget https://repo.skype.com/latest/skypeforlinux-64.deb
sudo apt install ./skypeforlinux-64.deb
rm skypeforlinux-64.deb


searching for specialized patterns using grep in a json file

Adding -z to your grep options will make grep treat newlines as null terminating characters (\0) as opposed to separate lines however they do not seem to be matchable in the regex. The workaround for this is to simply match everything (.*) up until the end of your desired pattern (in your case "created_at").

Next you can add -o to have grep only output what is actually matched, otherwise it outputs the whole file (since it is now essentially one giant line). Alternatively if the only purpose of outputting to a file is to later wc -l I would instead suggest you use grep's -c option which will print the number of matches rather than the match itself.

This translates to the following command:

grep -wirnEzc '},.*created_at' *

Expanding on this to include your previous pattern as well we get:

grep -wirnEzc '},.*created_at":\s"Wed Oct 19 2(1:[0-5][0-9]:[0-5][0-9]|2:([0-2][0-9]:[0-5][0-9]|30:00)) .* 2016' *


Can't type properly use AltGr after updating to Ubuntu 20.04

Somehow I just fixed it just by installing gnome tweaks tool and disabling the compose key under keyboard & mouse. Now I can use special characters like © or ª º


Video quality too bad while playing (any) videos in Intel GM965/GL960 Integrated Graphics Controller Ubuntu 12.04

I have a Dell desktop, running Ubuntu 12.04 (Unity 2D), with a Intel 82865G integrated video and it suffers the same thing.

That being said, I did install the drivers from Stefan Glasenhardt's PPA and the graphic quality of videos improved. Still not 100% but a lot better. Not sure if you had tried these or not; but they did make an improvement for me.

The PPA is: ppa:glasen/intel-driver and details for the PPA can be found at: https://launchpad.net/~glasen/+archive/intel-driver

Hope it helps. If you have tried it; sorry to waste your time.


Share Ethernet connection with second NIC (SmartTV)

If you are using a GUI: (Only works for IPv4)

Go in to the Network Connections setting
Click Add
Select Ethernet then click create
Use the drop-down list by the device option to enp6s0, or the desired device.
Click the IPv4 Settings tab
Click on the drop-down box beside Method, and change it to Shared to other computers
Click Save, then Close

Note: The TV, in this case, will not get an IP address registered by the router. It will still be able to access other LAN computers & the Internet, but other computers can't (without tunneling) access it.


error when using `sudo update alternatives`

I believe this:

sudo update-alternatives --install "usr/bin/java" "java" "usr/lib/java/jdk1.8.0_144/bin/java" 1

should be:

sudo update-alternatives --install /usr/bin/java java /usr/lib/java/jdk1.8.0_144/bin/java 1


I found a blog post that references an alternate download location. That location is on a dynamic DNS host, currently somewhere in Japan, likely a personal page. In case it goes down, I'll reference the download links below. They're all files in Google Docs.

While the instructions from the blog work for me, YMMV. I have the following disclaimers:

I have NO way to tell what the origin of these files is. They may be perfectly legitimate, or they may contain malware.
This appears to be a build of Moonlight v3, which the mono site describes as an upcoming release. It may not be what you expect.

With that, here are the current links:

Chrome

novell-moonlight-3.99.0.3-i586.crx
novell-moonlight-3.99.0.3-x86_64.crx

Firefox

novell-moonlight-3.99.0.3-i586.xpi
novell-moonlight-3.99.0.3-x86_64.xpi


Errors were encountered while processing: /var/cache/apt/archives/libc-bin_2.26-0ubuntu2_amd64.deb

Upgrading 14.04 to 17.10 isn't supported.

The package you are trying to install requires a more recent version of dpkg
 than the one you have. Try to download the .deb package from https://packages.ubuntu.com/artful/dpkg and install it using dpkg:

sudo dpkg -i dpkg_1.18.24ubuntu1_amd64.deb

(you may need to replace the file name and path). Maybe that works.

Consider doing a fresh install of 17.10.


How to fixed erlang unmet dependancy on ubuntu?

I got same error after installing old elixir and then manually adding the latest erlang repo on their website. Deleting the old version helped me:

sudo apt-get purge elixir
sudo apt-get purge erlang

After the purge, I could successfully install the:

sudo apt-get install esl-erlang


How to make the extra keys on my Sun Type 7 keyboard work in kubuntu 18.04?

First, I noticed that various Sun keyboards are listed in System Settings/Input Devices/Keyboard/keyboard model. So I chose mine, Type 7, with a UK layout.
Then I used xev and noticed that when I press any of the special keys, they are recognised and a keycode, the correct name and a keysym are displayed.
Also poking around the various X11 keyboard files it is clear that Sun keyboard support is definitely supposed to be there, at least in X.
After a lot of faffing around, in the end I used xmodmap to assign high-numbered function key values to the special keys. I put the commands in a script file I call sunkeys, which contains:
#!/bin/bash

# Assign F13 to F23 to the special extra Sun keyboard keys so that an action
# can be assigned to them. But Cut, Copy and Paste seem to work anyway.

if [[ -n "$1" ]]; then
  sleep "$1"
fi

setxkbmap -option ctrl:ralt_rctrl # Right Alt === Right Ctrl

xmodmap -e "keycode 146 = F13" # Help
xmodmap -e "keycode 136 = F14" # Stop
xmodmap -e "keycode 137 = F15" # Again
xmodmap -e "keycode 138 = F16" # Props
xmodmap -e "keycode 139 = F17" # Undo
xmodmap -e "keycode 140 = F18" # Front
#xmodmap -e "keycode 141 = F19" # Copy
xmodmap -e "keycode 142 = F20" # Open
#xmodmap -e "keycode 143 = F21" # Paste
xmodmap -e "keycode 144 = F22" # Find
#xmodmap -e "keycode 145 = F23" # Cut

(I'll come to the sleep bit in a moment.)
The function keys F13 to F23 are not on the keyboard but are in the X system and kubuntu System Settings knows about them, and when they are pressed it allows things to be assigned to them.
The setxkbmap line reprograms the right AltGraph key to be a right control key.
But although running sunkeys from the command line programs the keys ok, when I put sunkeys at the end of my ~/.profile file, the keys did not get programmed when I rebooted. It turns out for some reason there needs to be a delay before you run xmodmap, hence the sleep business in the script above. So at the end of my ~/.profile file I now have the line
~/bin/sunkeys 15 &

This makes the sunkeys script sleep for 15 seconds before it does the xmodmap commands. The & at the end of the sunkeys line tells the shell to continue booting while sunkeys sleeps. Without the &, you type your password when logging in and then the system then appears to hang for 15 seconds.
I now have all the extra keys doing the obvious useful functions. I assign Ctrl+S (= save in most applications) to the big Help key. And Ctrl++ and Ctrl+- for soom in and out to the unobvious Front and Props keys as they are next to each other.
As a bonus the Compose key actually does what it is supposed to with no further changes: to enter café I type c a f Compose e '.
Update: I did a quick test booting from a kubuntu 20.04 USB stick and it appears that System Settings sees most of the special keys, and displays their names correctly, with the exception of Front and Props. So when I eventually upgrade I will still use this technique.


cannot install application from source using tar.gz archive

try install autoreconf by following:

sudo apt-get install autoconf


# sudo su
# export LD_LIBRARY_PATH=$LD_LIBRARY_PATH:/lib/x86_64-linux-gnu:/lib/i386-linux-gnu
# apt --fix-broken install


Sublevel version mismatch when trying to compile current kernel

I had similar problem. The trouble lies with the method how you obtain the kernel source and how you "build" the kernel. There is a link to what the official way of doing it. I followed it from https://help.ubuntu.com/community/Kernel/Compile. By the look of it, it appears to be out of date and long reading.

Based on the situation I want to use the official released Ubuntu kernel (not from anywhere else) apt-get source xxxxx. It is a folder with Debian folder and a tar ball. Then I follow partial instructions from Trying to build kernel on 18.04. No editconfigs option

Download kernel sources (deb-src should be uncommented in /etc/apt/sources.list)

$ apt-get install linux-source kernel-package

Go to folder with kernel sources and untar

$ cd /usr/src/linux-source-x.x.x
$ tar jxvf linux-source-x.x.x.tar.bz2

Move content to current folder

$ mv linux-source-x.x.x/* .
$ rm -rf linux-source-x.x.x/

Get necessary packages

$ apt-get build-dep linux-source
$ mkdir debian/stamps

Then I can run fakeroot debian/rules clean and fakeroot debian/rules binary-headers binary-generic binary-perarch. In the middle I have to manually copy one amd gpu header file to the missing location, otherwise the compilation failed. This way the fakeroot debian/rules is using your running kernel configuration (uname -r).

If I use the make menuconfigure and .config, I end up the same problem as you. So you can use my sample to use official released Ubuntu kernel and fakeroot debian/rules to compile. The version of the module could match.

My version is Ubuntu 18.04, and my uname -r is 5.3.0-51. I use apt-get to get source around 2020-4-15.

I believe there are other ways to use make instead of fakeroot debian/rules, and it could help to build in-tree modules.


Server error (-5 - No address associated with hostname)

Per Charles' comment:
"dns-namservers" should be dns-nameservers (you missed an "e").


Problems dual-booting Windows 10/Ubuntu 14.04

I had the exact same problem and tried everything you did too. Finally this is what helped. I opened CommandPrompt as administrator and ran the following:

bcdedit /set {bootmgr} path \EFI\ubuntu\grubx64.efi

Hope that helps.


Login to Ubuntu and use Ctrl + Alt + F1 to enter TTY. Next, enter user name, password, and run the following command.

Code:

unity --reset

Wait until the process is complete and your user name appears again. Use Ctrl + Alt + F7 to renter the desktop environment.

If there is error reporting wait until finished. If Unity doesn't appear within a minute or two restart and login to Ubuntu and see what happens.

Try this for Ubuntu 14.04:

sudo apt-get install unity-tweak-tool

To reset Unity, do

unity-tweak-tool --reset-unity

Hope this will help.


Permission Stuck to read-only in my second Disk

You will need to learn about linux permissions. By default, a user can only write in his home folder, or in folders of removable drives mounted automatically under /media/.
Make sure the second volume is automatically mounted on startup. This can be set using the utility "Disks", or by manually editing the configuration file /etc/fstab yourself.
Then, you will need to change owners and/or permissions to what is desired. You can change the owner of the entire second drive if you wish that a single user can write to it. If there are multiple users, then you can create separate directories for each user and change the owners of each of them. To change owners, use the chown command:
sudo chown newuser:newuser /path/to/folder

will change both user and group of the folder /path/to/folder to user newuser and his group.


The same error occurred in my installation of Ubuntu 18.04 this is how I resolved it,

sudo apt install smbclient

I don't remember exactly but the same problem in my friends laptop resolved after running the following command python3-smbc is the package that was mentioned in the Ubuntu store error

sudo apt install python3-smbc


My mouse extra buttons' behavior just changed... help?

Setting Forward And Back Buttons
If all you want to do is set your four or five button mouse to use the extra buttons as "forward" and "back" buttons, you may have success with performing only a single action: edit /etc/X11/xorg.conf in the mouse section, and add the following two lines:

Option "Buttons" "7"
Option "ButtonMapping" "1 2 3 6 7"
Make sure to backup the file first, and restart X to have the effect take place. Assuming you are one of the fortunate people who only wants these functions and whose mouse buttons map as the "standard" behavior, you'll be all set.

From https://help.ubuntu.com/community/MouseCustomizations#Setting_Forward_And_Back_Buttons


How can older executables be run in Ubuntu 14.04?

The same rings true. You need to install what it needs. You can usually find out what it needs by running it in a command line and interpreting the errors and just installing the :i386 versions of those packages.

In this case...

sudo apt-get install libqtgui4:i386 libgl1-mesa-glx:i386

... Should be enough.


Low quality image rendering in gthumb/eog

This is bug 665897 in Gnome.

https://bugzilla.gnome.org/show_bug.cgi?id=665897


How to write cloud-specific application upon ubuntu cloud infrastructure?

Your question is very broad, but I'll try to answer it the best I can. Ubuntu provides you an OpenStack cloud, this handles your infrastructure. As far as how you're going to write your application on top of the cloud is really up to you.

Since AWS is a popular cloud here are some architecture documents that you can scan that give you an idea on how to design your infrastructure for a certain need. Though these apply to AWS and use AWS-specific services you can easily adapt it for OpenStack or any other cloud.

In this example AWS shows how to design a web application at scale. Applying this to your infrastructure OpenStack provides the ability to set this up, and Juju would deploy the services you need. So moving from front to back Juju would provide you a load balancer (by deploying HAProxy) your webservers (Depending on what technology you use, lets assume nginx), more load balancers (HAProxy), your application servers (depending on what technology you use, let's say a Rails app), and then your databases (pick one).

Ubuntu provides the means for you to deploy and run these services, and Juju provides a way to manage and orchestrate them. As far as to how to write a cloud application, people have written entire books on the subject so you might be better off starting with one of them.

See also:

http://www.infoworld.com/d/cloud-computing/developing-cloud-apps-whats-different-675?page=0,0
https://stackoverflow.com/questions/8244328/openstack-hello-world


Web login to college wifi network is not working anymore

Do you have to type the password in yourself?

If so, please don't forget that ubuntu keyboard works a little differently than a Windows keyboard does - namely, caps lock won't include punctuation or numbers.

Might be irrelevant, depends on the password, but it did cause me some trouble yesterday when I installed ubuntu 12.04 and tried to log in.


I had asked the same question today and got this answer:

https://askubuntu.com/a/910630/621017

It worked for me, but I had to reboot after uninstalling and only then reinstalled TB.


If your laptop is already connected to Internet then go to System Settings -> Network and then in the Wireless section, click on "Use as hotspot".
After the security notification, it will show you the network name and the wep key needed to connect to this network (those informations can be customized).
For more details, you can also check here.


What operating system do you have?

Mysql 5.5 is not officially available in Ubuntu 16.04.

This page shows how it is installed but I do not recommend installing it as a current version or at least version 5.6 is better.

https://gist.github.com/ahmadhasankhan/48fc9fc9a19807daef1622751a56884b


According to this reddit thread you can install FL Studio 12 on Ubuntu 16.04.

Here are the required steps from that thread:

Download playonlinux. sudo apt-get install playonlinux
Run it and make sure it launches. playonlinux
Go to Tools -> Manage Wine Versions. In Wine versions (x86), install the version 1.9.15. Select the version in the left box and click ">".
Click Install and then Install a non-listed program.
Click through the welcome screen.
Select "Install a program in a new virtual drive".
Pick a name for your virtual drive (like "flstudio").
In the next window, don't check anything and click Next.
Select "32-bit Windows installation". Then wait a minute while your drive is being created.
Next click Browse and look for your FL Studio installation .exe. One thing to note is that your main file system in Wine is always mapped under the disk letter Z:.
Click through the installation. Once you reach the "Choose which features of FL Studio 12 you want to install", uncheck Desktop icons and Asio4All. Install everything in its default directories.
In the final screen, select "FL" as your shortcut.
Once FL Studio is installed, try to run it and make sure it launches. You will most likely not see any text and the program will not be registered.
To fix the no text issue, select the FL in your playonlinux main window, go to Configure -> Install components and install the Microsoft Core Fonts and tahoma packages.
To register your copy of FL Studio, go to Configure -> Wine -> Registry Editor. Then go to Registry -> Import Registry File... and navigate to where your registration key is located. Then exit the registry editor.
Launch your FL Studio and verify that everything works (for instance, open newstuff.flp).
Open audio settings and set your sound driver to FL Studio ASIO.

For more info regarding the known issues and errors please refer to the thread.

And if that is not working for you , the most probable solution will be either to use a windows virtual machine or dual boot ubuntu with windows , if you are not interested in going the either way , the best possible solution will be a combination of lmms and audacity.


How do I switch default root authorization app?

The policykit dialogs are unrelated to gksu.
You will have to purge the package:

    polkit-kde-1

The gtk+ dialog comes from package:

    policykit-1-gnome

if you accidentally removed it while installing KDE.


Configure Caps Lock as AltGr and Arrows like in vim

1. add a new XKB partial file
sudo vi /usr/share/X11/xkb/symbols/altgr_vim

with this content:
partial keypad_keys
xkb_symbols "altgr-vim" {
  # replace Caps with AltGr
  key <CAPS> { [ ISO_Level3_Shift            ] };
  # Add vim cursor keys to be accessed with AltGr
  key <AB02> { [ x, X, Delete, Delete        ] };
  key <AC02> { [ s, S, KP_Enter, KP_Enter    ] };
  key <AC03> { [ d, D, Next, Next            ] };
  key <AC04> { [ f, F, BackSpace, BackSpace  ] };
  key <AC06> { [ h, H , Left, Left           ] };
  key <AC07> { [ j, J, Down, Down            ] };
  key <AC08> { [ k, K, Up, Up                ] };
  key <AC09> { [ l, L, Right, Right          ] };
  key <AD07> { [ u, U, Prior, Prior          ] };
  key <AE03> { [ 3, section, Home, Home      ] };
  key <AE04> { [ 4, dollar, End, End         ] };
};

2. include the partial in your language file
for example for german it is /usr/share/X11/xkb/symbols/de (where /de is your language) add this inside the first block (xkb_symbols "basic"):
include "altgr_vim(altgr-vim)"

Note: This part has to be repeated after every distribution update
3. reload the window session
Press ALT+F2, enter "r" to reload the gnome session or just log out and in again. Now the new key compositions will be available
4. solve some problems

Some applications don't accept the settings, for example: sublime which can be replaced by atom.

Some applications need extra settings, e.g. in yakuake the key-bindings are set to "XFree 4", if you set them to "Linux" or "Solaris", then the XKB settings works there also:

remaining problems:

some apps still don't accept those settings
after an upgrade, where the symbols file is updated, you have to repeat step 2


Get GRUB prompt after adding Ubuntu 18.04 to dual boot with Windows 10

It sounds like there is some kind of problem with grub, the bootloader. Try booting off the USB stick again and use boot-repair as outlined here. That usually fixes most issues.

If that doesn't work, please post a link to the summary report boot-repair creates.

Good luck!


According to FHS standards documentation files are usually installed in /usr/share/doc.

For groovy you will find these files in /usr/share/doc/groovy-doc. The documentation can be viewed in any browser by opening

file:///usr/share/doc/groovy-doc/groovy-jdk/index.html


Change the complete KDE Desktop Look like a Theme?

There is a KDE4 desktop theme manager in the advanced tab of the settings panel. But if you need to change things outside of that then you need to talk with the kde developers in order to make something more complete and cohesive. So far people on http://kde-look.org/ probably have the most advanced ideas on how to publish and deploy entire themes.

Anything they don't know, probably doesn't exist.


Can't login due to unity/gnome config problem

Seperate your login issues from X issues.

First try logging in to a VTY. Press Ctrl + Alt + F1 and login.

Once logged in try running sudo X :2 & you should be taken to a black screen with a X for a mouse pointer. If you do then X is fine, and your problem is your configuration of either lightdm or your desktop. This is common with large upgrades.

If X doesn't start then back at the terminal (etrl + alt + f1) run cat /var/log/X.2.log | grep EE that will return all errors. We will need that to really go any further down this path.

If X did start then go back to the terminal (ctrl + alt + f1) and create a new user, then try to log in using that user. sudo adduser testing will create a new user called testing.

If you were able to log in as testing, then your personal configuration is borked. If you could not log in as testing (in X) then lightdm is borked.

To fix your login the best way is to just delete (after backing up of course) your home directory contents. Then copy back the files you need from backup. This will reset all your settings but is a sure fire way to make sure your config issue is addressed. You could also delete just the .config directory, or all the hidden directories. However make sure you have backups.

To fix lightdm, you can probably just do sudo dpkg-reconfigure lightdm. If it's still lightdm and still causing the issue, we will need the full lightdm log (/var/log/lighdm) use pastebin or something to add it to your question.


How to remove duplicate imported photos in Shotwell

Sort of spamish, but I found myself with the same problem a few monts ago, and I wrote a small utility that does just that:

https://github.com/jesjimher/imgdupes

It's a python script that scans a directory tree looking for duplicates. Its syntax is intentionally similar to fdupes, with the difference that imgdupes ignores all metadata and analyzes only the image data chunk of a JPEG file. This means that two different versions of the same image, with different tags, rotation flags, dates, etc., will be reported as duplicates even if physical files are different (and thus not detected as duplicates by fdupes/shotwell).

It was recently renamed to jpegdupes, and is now on Pypi repos, so scanning a tree for duplicated images might be done like this:

sudo pip install jpegdupes
jpegdupes -d ~/Photos/ (or whatever your path is)

It would look for JPEGs which are actually the same picture (differing only in metadata), and would interactively show differences and ask for which version to keep.

Hope it helps.


For me it was two places causing motd to be displayed twice:
1) pam.d
2) sshd

~> cd /etc/pam.d
~> grep -i motd *
and then editing /etc/pam.d/sshd  (may differ from version to version so confirm with grep output)
and hash out these two lines:

session    optional     pam_motd.so  motd=/run/motd.dynamic
session    optional     pam_motd.so noupdate

My /etc/ssh/sshd_config also had #PrintMotd=yes (default is yes so it was active even if it was #'d out)

In the end I set /etc/ssh/sshd_config MOTD option to PrintMotd=no (not removed the # and set to no to replace the default) and enabled the /etc/pam.d/sshd motd lines so the /etc/ssh/sshd_config option printlastlog=yes will print the last login information after the pam.d motd is displayed.

Pam will also use the options in /etc/update-motd.d/ to customise the /etc/motd as well which sshd will not do as it will simply display what is already there.


This was easy:

boot into a console or start a tty
sudo mount /dev/sda5 /mnt    (sda5 is the drive where / is mounted)
ls -l /mnt

now you should see a /mnt/@ which is the new system and a /mnt/@snapshot... which is the old system. Exchange the new system with the old system:

sudo mv /mnt/@ /mnt/@failed
sudo mv /mnt/@snapshot... /mnt/@

and reboot. That was it.


This answer assumes that you have a separate boot partition.
The Update is asking for more space in boot partition.
Your screenshot is giving the details of root partition.
How to solve?
Install GParted (Available in Software Centre).
You will be able to see detailed information about the partition sizes using GParted.
It has a nice Graphical Interface that will let you compress or expand the partitions as per your need.
Note: You need free-space on either side of a partition to expand it.
If you don't have free space, you will have to compress the nearby partition to expand it.
Check out detailed tutorial on GParted here.


ecryptfs-recover-private mounts wrong filesystem

ecryptfs-recover-private error handling is seriously lacking.  My version has a bug where it returns success even when you give the wrong mount password. It also gives success when you try to mount just about any directory, regardless of whether it actually contains ecryptfs data or not.

Your problem is you are trying to do the obvious thing and mount home/username/.Private.   That won't work!    Instead, you need to mount home/.ecryptfs/username/.Private.

Try this:

ecryptfs-recover-private /mnt/externalhdd/home/.ecryptfs/user/.Private/

Follow the prompts and use the login passphrase for your old account, or the mount passphrase if you have it.

Once the mount is complete, you should be able to access the contents of your old account.


Plotting multiple sets of data in libreoffice calc

You can do that easily. This is not an ubuntu question though, I think.

Anyway, in libre-office calc go to "Insert - Chart".

After creating a chart (XY (scatter) probably), right click on it and click on "Data ranges". A menu will pop out. Go to the tab "Data series", and add as many data series as you want. Each data series consists of a graph. Looking at your link, you'll probably want 3 data series, 1 for each solution! The lines will have different colors, and you should edit their legend for easier comprehension.


gcc "no such file or directory" error when attempting compilation

Case is important, test.c is not test.C.
gcc will actually    accept either case .c, if it exists.
gcc by default rejects extensionless files, but steeldriver showed you how to override that (which is certainly not standard practice).
gcc can produce an output for a name you supply, -o test.out using your example.  The standard user setup includes a bin directory in the home directory, and this is the usual place to add private scripts because it is already in your PATH.  For instance, in ~/bin, add a file named mygcc containing
gcc -o "$1".out ${1}.c
to compile your files anywhere with the new command mygcc test
Alter to fit your needs -- pass explicit names executables, pass the entire test.c name, etc.
Running from the local directory without the ./  (as ./test.out) is
    made possible by adding "." to the PATH variable (edit the .profile
    in your home directory to do this)

The .profile file in your home directory is just a text file owned my you, so any editor will work, but choose one which will not wrap lines for you.  The PATH variable is usually set up near the bottom, so you may add the :. to the end of an existing PATH=... line, or make a new one like

PATH=${PATH}:.

Adding the . to the end is "safer" than at the beginning, so it cannot override any system programs of the same name.  Running any non-system program entails some risk, (where did it come from, what does it do,...?) but if the program is one you are creating (source and all), those risks are less.  It may be worth the convenience to test new compiled programs, your choice.


Can OO Presentation go full-screen to the secondary monitor?

Yes it is possible.

Go to Slide Show -> Slide Show Settings... and select the desired display as your Presentation display.

Now if you start your presentation using F5 it will be displayed on the selected display.

The same applies for LibreOffice.


Ubuntu 12.04 stereo duplex sound problem

Setting the soundcard profile was limited in gnome-control-center for a simpler user experience (see bug #972554). This also affects the switching to Analog stereo from Analog duplex stereo. We can still do this with pavucontrol . This may also improve the noise you are experiencing when no device is plugged in the input jack.

From the log files attached to bug #1027570 we can see that we try to switch to the microphone port but fail. We may disable the automatic switching by commenting out the following line in /etc/pulse/default.pa to look like this:

# load-module module-switch-on-port-available

This requires editing this file as root (e.g. by running gksu gedit /etc/pulse/default.pa). To take effect we need to restart pulseaudio with

 pulseaudio -k

If that does not help please remove the # again to re-enable switching audio to a new audio port when it becomes available.


Does using -v (verbose) slow commands down?

Yes, the -v flag slows down the command.

Most, if not all softwares(or commands) would check if a flag is provided, and then execute a bunch of code related to the flag. In case of the -v flag, they would likely execute a bunch of output commands(like echo or printf), which they rather would have skipped without the flag.

This means more instruction cycles for the processor and thus more execution time.

It is better if you don't use -v flag if you are not going to read/need the messages.

On the other hand, the CLI would/should be faster than GUI, assuming that you don't include time required to type the commands and pressing the Enter key.

From this blog of superuser this image explains the slowness very well

For the specific command in question, the results of the time command are

//with -v
real    0m8.753s
user    0m0.816s
sys     0m2.036s

//without -v
real    0m1.282s
user    0m0.124s
sys     0m1.092s

this was done with the directory containing 100000 empty files


How do I create a file and mount it as a filesystem?

Your procedure is correct, but when mounting a file image as a filesystem you have to add the -o loop option to the mount command:

mount -t ext3 -o loop file /media/fuse

Also, the -t ext3 option is not strictly required, because mount can automatically determine the filesystem type.


'Clearing orphaned inodes' and state lost on hibernation resume

Well, I am surprised nobody suggested this as I have been having this problem for quite some time. The answer it seemed was staring right in my face. Apparently my swap partition was roughly the same size as my memory. Also, I hadn't added the link to my swap partition's UUID in my grub file. After increasing the swap partition size to double that of the memory and adding its UUID in the grub file the hibernation resume is working normally for the past few days. Although, the resume from hibernation takes a tad bit longer but I'm not complaining.

You need to make sure that your swap partition is defined in the following files:

/etc/initramfs-tools/conf.d/resume
/etc/default/grub

UPDATE

Using low level interface uswsusp as default hibernating mechanism drastically improved my resume time to under a minute !!!

sudo apt-get install uswsusp

Create file /etc/pm/config.d/00sleep_module and add following line:

SLEEP_MODULE="uswsusp"


VMWare Virtual Machine Monitor Failed in Ubuntu 16.04 LTS

I solved this problem.

Ubuntu 16.04, VMware Workstation 12.1.0 build-3272444

Disable Secure Boot in my BIOS.
Run

sudo su -
vmware-modconfig --console --install-all


Keeping old Gnome 2 while upgrading to newer versions

You have many disparate issues here I want to address.

Ubuntu Server is (as far as is important for your use) just Ubuntu without the graphical desktop packages installed. That is to say, if you want a clean install of Ubuntu Server with a graphical desktop, you might as well just install the Ubuntu spin for that desktop (eg Ubuntu Mate, Kubuntu, etc) and then install things like LAMP (or whatever server tasks you need) with tasksel or Apt.

The Ubuntu desktop of the 2010 era is long gone. It moved onto Unity. If you upgrade the ubuntu-desktop metapackage will pull you onto Unity. You could just uninstall those packages before upgrading (and run an apt-get autoremove) and then install whatever -desktop metapackage (probably mate-desktop) when you're done upgrading the core system.

10.10 has been dead for years. As has 11.04 and 11.10. You'll need to upgrade through all of those to get to 12.04 and from there you should be able to LTS-hop to 14.04. That's another reason for getting rid of any non-essential packages (less to upgrade).

Honestly, I'd be weighing up whether it's not best to back-up and do a fresh install of Ubuntu Mate (or whatever desktop spin takes your fancy - there are many now). It'll be much faster for you and will likely leave you with a better result.


Is there a workaround for the RFC 5961 Linux TCP flaw?

Note: The Workaround section has been kept for historical reasons, however please skip down to the Fix section below.

Workaround:

As stated here:

  The good news -- and, yes, there is good news -- is it's easy to fix.
  First, Linux itself is being patched to stop the attack vector in its
  track. Next, you simply raise the 'challenge ACK limit' to an
  extremely large value to make it practically impossible to exploit the
  side channel problem that enabled the attack to work.

As this issue affects both the client and server, or in fact any two Linux machines talking over the network, it is important to implement the workaround in both, and the fix as soon as it is released.

In order to implement the workaround do the following:

Open the config file with: sudoedit /etc/sysctl.conf
Insert the line net.ipv4.tcp_challenge_ack_limit = 999999999 into the file and save it
Run sudo sysctl -p to update the configuration

You can also do the operation directly from Terminal:

sudo bash -c 'echo "net.ipv4.tcp_challenge_ack_limit = 999999999" >>/etc/sysctl.conf'

Or:

echo 'net.ipv4.tcp_challenge_ack_limit = 999999999' | sudo tee -a /etc/sysctl.conf

Then run:

sudo sysctl -p

Fix:

As stated here:

net/ipv4/tcp_input.c in the Linux kernel before 4.7 does not properly
determine the rate of challenge ACK segments, which makes it easier for
man-in-the-middle attackers to hijack TCP sessions via a blind in-window
attack.
...
sbeattie> fix is going to land in Ubuntu kernels in this SRU cycle,
with a likely release date of Aug 27. Earlier access to the kernels
with the fix will be available from the -proposed pocket, though they
come with the risk of being less tested.

And a fix has now been released:

linux (4.4.0-36.55) xenial; urgency=low

  [ Stefan Bader ]

  * Release Tracking Bug
    - LP: #1612305

  * I2C touchpad does not work on AMD platform (LP: #1612006)
    - SAUCE: pinctrl/amd: Remove the default de-bounce time

  * CVE-2016-5696
    - tcp: make challenge acks less predictable

 -- Stefan Bader <stefan.bader@canonical.com>  Thu, 11 Aug 2016 17:34:14 +0200

Run:

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

To make sure you have the latest version. Or use the Software Updater if you would prefer to update through the GUI.

You can check which version you are running and which is available with:

apt-cache policy linux-image-generic


Ubuntu 16.04 32-bit does not boot after sudo apt upgrade

I would suggest to disable plymouth. Having acces to the console it is easy.

Log in the console.
Edit /etc/default/grub (as root, for example sudo nano /etc/default/grub)
Change the line

GRUB_CMDLINE_LINUX_DEFAULT="quiet splash"
to

GRUB_CMDLINE_LINUX_DEFAULT=""
And then update grub and reboot

sudo update-grub && sudo reboot


This might not be exact solution that you want, but could try this:
If you install JDK by this method:

Linux Jdk installation

Adds PPA for JDK

sudo add-apt-repository ppa:webupd8team/java

Updates PPA

sudo apt-get update

Installs JDK

sudo apt-get install oracle-java7-installer


how to restore missing video folder in nautilus

Edit the file ~/.config/user-dirs.dirs and change the line XDG_VIDEOS_DIR to

XDG_VIDEOS_DIR="$HOME/Videos"

You may need to restart your session


The Dock keeps opening if mouse is scrolled to the left in Minecraft

I'm running Minecraft 1.15 on Ubuntu 20.04, but have experienced this problem since Ubuntu 18.04. One less than great solution, which improves (but does not eliminate) the issue:

Increase the pressure required to unhide the dock with the dconf-editor. Setting is located at /org/gnome/shell/extensions/dash-to-dock/pressure-threshold, I found that 275.0 is about as much as you can increase it without becoming annoying outside of Minecraft.

But finally it seems there is a better way to do this! Minecraft recently added some new mouse settings to the control menu, and I was able to eliminate the issue entirely by disabling raw input in my Minecraft mouse settings. Can also be done by editing ~/.minecraft/options.txt and setting rawMouseInput:false. You can still access the dock with Minecraft maximized by opening the menu and moving your cursor to the dock location, like normal.


Installing ubuntu and drives partitioning

This is link for installing Ubuntu Here

During installation  choose the ’Something else’ option to create partition.

All if you want install Ubuntu & after that you want to create partition  than use Gparted or also you can first boot using USB or Live CD than create partition using Gparted.
Gparted

I hope this is help you.


Picked up _JAVA_OPTIONS: -Dawt.useSystemAAFontSettings=gasp

As mentioned by @ByteCommander above, it is set by either one of those file, but it could also be in {netbeans-installation-dir}/etc/netbeans.conf under netbeans_default_options. You can just remove it to get rid of the message, but note that you might have blurry text in some swing applications.


Segmentation fault when I try to launch unity-control-center

The error is possibly due to nvidia graphic card.
To mitigate the error I used the following command:
prime-select intel.

Try opening the unity-control-center now. My unity-control-center was working fine under nvidia graphic drivers but stopped when I changed the xorg.conf by switching to intel graphic drivers for screen. It might be the possible cause of introduction of this error.


Do not expect the same performance using Wine compared with Windows. Wine as you probably know is used to emulate all layers necessary to run Windows applications, it will never be the same as you have in a Windows system.

For increasing the FPS I would suggest running all your gaming sessions under Unity2D, that is important because you do not have the composite desktop taking part of your graphics card performance.

For World of Warcraft as you said changing from D3D to OpenGL helps in most cases bit in the end you will have to eventually lower the graphic details options to run the game.

Try a lower resolution, decrease the graphic details a bit and them some more until you are happy with the performance.

When I played World of Warcraft on my Ubuntu system I noticed 2 things always: lag and ping to server was much better and graphics quality always had to be much lower than the one I used in Windows.


How do I get a Canon PIXMA iP3600 printer to work?

I found the solution here:

http://www.hrupin.com/2010/12/linux-ubuntu-10-04-driver-for-canon-ip3600-ij-printer

All is OK there, only that the installation of the deb drivers must be done with the command: sudo dpkg -i --force-all *.deb

The procedures I used forced the printer (Canon PIXMA iP3600) to work, but I met problems to install other soft because of the unmet dependencies. Finally I run the command the system recommended:

sudo apt-get -f install

without any packages and accept everything. This corrected the problem of dependencies but deleted the printer drivers I installed before (off course!).

Finally, the solution was to let the system install the printer when  a connect it to the computer and then going in to "System Settings" > Printing rigth click in the printer, select Propierties adn then, in the line of Make and Model click on Change. The system will offer a lot of drivers (in my case I selected Canon list), so I tried all the PIXMA ip drivers up than 3000 (The system recommends PIXMA ip3000 but it doesnt work for the ip3600). Finally the driver PIXMA ip4600 worked for me, it prints the Test page.


Create live wallpaper slideshow that changes based on date rather than duration

You can try using conky. If the tool can create a calendar or clock on desktop maybe it can also change the background?


Your processor is Intel Pentium N3540. This is affected by the c-state bug, where the processor attempts to go into unsupported sleep states. This happens with many Baytrail devices when using newer kernels. I have the same problem.

There is a simple workaround for this until it gets properly fixed upstream. You just need to pass a kernel boot parameter and the random freezing stops completely.

You do this by editing the configuration file for GRUB

sudo nano /etc/default/grub

Find the line GRUB_CMDLINE_LINUX_DEFAULT="quiet splash"

This needs to be changed to include intel_idle.max_cstate=1

So after your edit it reads

GRUB_CMDLINE_LINUX_DEFAULT="quiet splash intel_idle.max_cstate=1"

If you have other boot parameters already besides quiet and splash, just leave them alone.

Now save the file and exit, and run

sudo update-grub

After reboot, the problem will be fixed.


How to rename more than one files in ubuntu?

I'm not sure how you want them numbered, but the following Perl script should do it (haven't tested it out, but should probably work):

#!/usr/bin/perl
@a=glob("*.jpg");
$n=1;
for(@a){
    rename $_,($n++).".jpg";
}


Setting a greyscale (or monochrome) color scheme

Compiz has a few filters which supposedly can do what you want.

Install Compiz Config Setting Manager from Ubuntu Software Center    or with sudo apt install compizconfig-settings-manager.
Run it and under Accessibility category you'll find Color Filter and Opacity, Brightness and Saturation filters.
There you'll be able to enable them, assign a keyboard shortcut and edit the filters' settings.

Now, I have to admit that I wasn't able to test it since I only have Ubuntu in a virtual box without 3D acceleration, but hopfully it'll give you some pointers.

Also, please don't get too excited modifying Compiz settings - it is quite easy to break Unity by doing so. The filters I mentioned above should be quite safe though.


Single command to open various applications

Here's what I'd do:

for i in google-chrome nautilus gnome-terminal gedit ; do
    setsid "$i" >  /dev/null 2>&1
done

setsid or nohup can be used to daemonize a process, with setsid being preferred because it starts each process as new session leader, effectively disconnecting it from terminal.  See also, Difference between nohup, disown and &.

As for > /dev/null 2>&1 that just sends both normal and error streams from each program into /dev/null so that you can still use terminal normally. See also What does & mean exactly in output redirection? and What is the differences between &> and 2>&1

I don't remember command for system monitor off the top of my head, so I'll leave that up to you.

Feel free to turn this loop into either a function that can live in your ~/.bashrc or make a full-blown scripts. Up to you.


Ubuntu appears to have transitioned from hg-buildpackage to mercurial-buildpackage with the release of Ubuntu 10.04 (Lucid).

The manual for mercurial-buildpackage explains that it "originates  from  John  Goerzen’s  hg-buildpackage," but since it is not an exact replacement there is no transitional package to guide users who are looking for hg-buildpackage by name.


You can used sed :

[romano:~/tmp] % echo test >! test.c
[romano:~/tmp] % sed -i -e "1i #include" test.c
[romano:~/tmp] % cat test.c
#include
test

...just take care of the correct quoting.

More verbose: sed -i means to edit the file (the last argument) in place; the command "NiSomething" insert Something at line N.

PD this works on Linux and (GNU sed) 4.2.2 --- POSIX sed require a stricter syntax.


What metadata does Shotwell not add to photos?

Based on this page on their wiki, it appears that Shotwell can only write keywords, titles, ratings, and orientation. I've used all these and I don't know of any other user modifiable fields (besides adjusting date & time) that Shotwell can do. It looks like all the metadata that Shotwell can modify is written to the original file, if you enable that option in the preferences.

Here is another page from their wiki in which they are looking at metadata and interoperability with other programs and services. If any other fields become user-modifiable, they will probably be documented there first.

There is at least one Shotwell developer here using Ask Ubuntu, and you will probably get a more definitive answer soon. It looks like the original wording you quoted in your question just included a catch-all term that was not specific enough.

tl/dr YES, Any metadata you edit with Shotwell is written to the file, as of the current version.


Ubuntu 14.04 does not recognize sound card

I had the same problem. You can solve it using the following command:

sudo aptitude --purge reinstall linux-sound-base alsa-base alsa-utils linux-image-`uname -r` linux-ubuntu-modules-`uname -r` libasound2

Then just restart the computer.


clang and clang++ not found after installing the clang-3.5 package

It's there, but it's still called clang-3.5.

You can either execute it as clang-3.5 (or clang++-3.5) or setup a symlink to it like I did (installing regular clang didn't work):

sudo ln -s /usr/bin/clang-3.5 /usr/bin/clang
sudo ln -s /usr/bin/clang++-3.5 /usr/bin/clang++

Ugly work-around, perhaps; but at least it works for now :)


How do I enable VDPAU hardware video acceleration support for non Nvidia cards?

VDPAU is a programming interface (API) to allow offloading of graphics rendering to the Graphics Chipset rather than handling by the CPU itself.

It is opensource - produced initially by Nvidia themselves and supported on most of their current Graphics Cards.

Wikipedia has an excellent article on this:

  S3 Graphics added support for VDPAU to the Linux drivers of its Chrome
  400 video cards since version 14.02.17 of its device driver for Linux,
  it supports the S3 Chrome 430 GT, S3 Chrome 440 GTX, S3 Chrome 530 GT
  and the S3 Chrome 540 GTX hardware.

  Intel and ATI currently offer no support for VDPAU. Nvidia hopes these
  GPU designers will support the open source VDPAU library and provide
  drivers with VDPAU acceleration by mentioning example names of
  hardware specific drivers for Intel and ATI: libvdpau_intel.so and
  libvdpau_ati.so.

Intel currently support their own rival API called VA-API.

ATI/Radeon are concentrating their efforts on their Catalyst Drivers - again they have their own API called XVBA but is only supported through their Catalyst Drivers.

Phoronix over the last few months have been reporting the development of another API called the Gallium 3D State Tracker - this is intended to unify the main chipsets - Intel, ATI/Radeon and NVidia.  In simple terms (as far as I understand it) - it tries to overlay an API ontop of VA-API, VDPAU etc.  Thus you program to the Gallium API and it will translate this to the rival APIs for you.

Much of this is bleeding edge code - unstable and you will often have to compile code etc to keep up with the latest developments.  The X-Edgers PPA is a good source of latest developments - an article here described installing the opensource radeon driver and forcing the use of Gallium3D.

Back to topic... as you can see, graphics in linux is currently fractured (some call it a mess!) - thus the best solutions at the moment is to use media players that attempt to implement the rival API's such as MPlayer.

UPDATE

The above was the past ... 2011
At the present 2015, VDPAU is supported by intel and amd as well as archWiki page stats

You should install the following package for intel

sudo apt-get install libvdpau-va-gl1 i965-va-driver

but looks there is an open bug on Ubuntu 14.04 and on 14.10 as well, so the lib is not found ... so for ex. vlc through the following error:

Failed to open VDPAU backend i965_drv_video.so: cannot open shared object file: No such file or directory

There is a workaround in the bug page, I'm not coping it here because even if I apply it the video is not playing in vlc ( looks the library is broken )


Security - Apache's websites folder inside Home folder

The best way (my opinion) is to use a different user for apache (www-data, apache) and use the following method:

create an FTP location that has the subdirectories of your website. Chroot this location. For traceability I would use different users if there is more than 1.
setup a cronjob (/etc/crontab with the apache user as the one executing this) with a script that scans the directory for new content every few minutes. If new content found let it make a backup of the files on the apache side (compressed tar file with username and a timestamp in the filename) of the files found on the ftp side.
let the cronjob copy the files over. You could finish this off with  a confirmation mail that this was done by 'user' and include a diff of the differences.

In case something goes wrong you can

track who did it.
what this person did.
undo what he did.

Do not use the documentroot for development. 1 typo can kill the website and then someone has to find this typo and fix it.


Without knowing for sure, it sounds like you're attempting a Wubi installation.

If you are trying to install Wubi to the folder C:\Ubuntu, but that folder already exists and has files in it, the installer won't let you continue.  You need to delete that folder (and all its contents).

Open up your C:\ drive (open My Computer, double click on the C: icon.  It may make you click Show folder contents before displaying the folders).  Right click on the Ubuntu folder and select move to trash.   Alternately, you could rename it in case there are important files in there you don't want to lose.  (right click -> rename -> choose new name).

Here's a Wubi guide


How to restore a degraded drive back into a zpool?

I fixed it by experimenting (since export and import are no-destructive).

Looking at blkid, I could see that both drives had the same UUID:

root@gomez:/dev/disk/by-uuid# blkid
/dev/sda1: LABEL="OS" UUID="e82b3fae-dce5-4b41-bd87-1f7bbd5f8039" TYPE="ext4" PARTUUID="5805358e-01"
/dev/sdb1: LABEL="zpool_primary" UUID="9579775147971336578" UUID_SUB="6175940412684032547" TYPE="zfs_member" PARTLABEL="zfs-efd142ee34d8cfea" PARTUUID="018883e2-0067-ac4b-8126-a2c02d0cfa45"
/dev/sdc1: LABEL="CCTVPartition" UUID="6b35ec61-13aa-46f9-b6b7-dfd4b264318f" TYPE="ext4" PARTLABEL="primary" PARTUUID="a31f929b-0989-4baa-8faf-082be6fca607"
/dev/sdd1: LABEL="zpool_primary" UUID="9579775147971336578" UUID_SUB="15142782844563214281" TYPE="zfs_member" PARTLABEL="zfs-693944edaab7d9e6" PARTUUID="91203b94-8387-1e4e-8646-5ba2cb6c461f"
/dev/sdb9: PARTUUID="e18a4bf7-b4c9-2149-bcd2-19ab9ba2182c"
/dev/sdd9: PARTUUID="009580ae-4c61-ab4d-a923-b7dc6ba14faa"

I therefore imported the drive using the UUID (and validate the import using zdb):

root@gomez:/dev/disk/by-id# zpool import -d /dev/disk/by-uuid/ zpool_primary
root@gomez:/dev/disk/by-id# zdb
zpool_primary:
    version: 5000
    name: 'zpool_primary'
    state: 0
    txg: 1160981
    pool_guid: 9579775147971336578
    errata: 0
    hostname: 'gomez'
    com.delphix:has_per_vdev_zaps
    vdev_children: 1
    vdev_tree:
        type: 'root'
        id: 0
        guid: 9579775147971336578
        children[0]:
            type: 'mirror'
            id: 0
            guid: 17679195099076183548
            metaslab_array: 256
            metaslab_shift: 36
            ashift: 12
            asize: 8001548713984
            is_log: 0
            create_txg: 4
            com.delphix:vdev_zap_top: 129
            children[0]:
                type: 'disk'
                id: 0
                guid: 6175940412684032547
                path: '/dev/sdb1'
                whole_disk: 1
                create_txg: 4
                com.delphix:vdev_zap_leaf: 130
            children[1]:
                type: 'disk'
                id: 1
                guid: 15142782844563214281
                path: '/dev/disk/by-uuid/9579775147971336578'
                whole_disk: 1
                create_txg: 4
                com.delphix:vdev_zap_leaf: 131
    features_for_read:
        com.delphix:hole_birth
        com.delphix:embedded_data

The pool was up and running, just with unusual identifiers:

root@gomez:/dev/disk/by-id# zpool status
  pool: zpool_primary
 state: ONLINE
status: One or more devices has experienced an unrecoverable error.  An
        attempt was made to correct the error.  Applications are unaffected.
action: Determine if the device needs to be replaced, and clear the errors
        using 'zpool clear' or replace the device with 'zpool replace'.
   see: http://zfsonlinux.org/msg/ZFS-8000-9P
  scan: none requested
config:

        NAME                     STATE     READ WRITE CKSUM
        zpool_primary            ONLINE       0     0     0
          mirror-0               ONLINE       0     0     0
            sdb                  ONLINE       0     0     0
            9579775147971336578  ONLINE       0     0     1

I then exported it again, and finally reimported using by-id:

root@gomez:/dev/disk/by-id# zpool export zpool_primary
root@gomez:/dev/disk/by-id# zpool import -d /dev/disk/by-id/ zpool_primary
root@gomez:/dev/disk/by-id# zpool status
  pool: zpool_primary
 state: ONLINE
  scan: none requested
config:

        NAME                        STATE     READ WRITE CKSUM
        zpool_primary               ONLINE       0     0     0
          mirror-0                  ONLINE       0     0     0
            wwn-0x5000cca27ec5c30d  ONLINE       0     0     0
            wwn-0x5000cca252f6d327  ONLINE       0     0     0

errors: No known data errors

Hopefully this helps someone else. I learnt the hard way about building raids and fstab etc with dev/sdx identifiers. Won't be making this mistake again.


Ubuntu 12.10 can't adjust brightness on my laptop

To get working brightness key. try following

press Alt+f2 , execute gksudo gedit /etc/default/grub

Change this line

GRUB_CMLINE_LINUX_DEFAULT="quiet splash"

to something like below

GRUB_CMDLINE_LINUX_DEFAULT="quiet splash acpi_backlight=vendor"

Open a terminal by Alt+ctrl +T, Execute sudo update-grub and reboot . See if brightness keys are working.

If the above is not working set a fixed value for brightness. To do so,

Open a terminal by pressing Alt+ctrl+T.

Type ls /sys/class/backlight/*/brightness, copy the outputs to a separate text file

The possibility is there will be two paths,try the following for each path and replace accordingly

example paths will be like

/sys/class/backlight/acpi_video0/brightness

Run following commands in terminal,

For the above path Get the maximum brightness:

cat  /sys/class/backlight/acpi_video0/max_brightness

Try a lower value to set the brightness, say output is 16 so I will try with half of it

echo 8 | sudo tee  /sys/class/backlight/acpi_video0/brightness

If this works,  make this happen in each login automatically by doing the following

gksu gedit /etc/rc.local

Enter this line just before exit 0. It should look like

echo YOUR_VALUE_HERE > /sys/class/backlight/acpi_video0/brightness
exit 0

Also you can try with xdotool

More info here.


Which tools helps to start Ubuntu GUI when boot?

The ubuntu-desktop package should have depends on everything you need.


Can I set up GNOME Terminal to have a toolbar?

$ sudo apt-get install xfce4-terminal
...
The following NEW packages will be installed:
  exo-utils libexo-0.3-0 libexo-common libxfce4util-bin libxfce4util-common
  libxfce4util4 xfce4-terminal
After this operation, 10.0MB of additional disk space will be used.
...
$ xfce4-terminal &
$ gnome-terminal &

Ten megabytes is a little large for a terminal, but it does happily co-exist.


Installing postfix - Problems with apt-get

It appears that you don't have an internet connection. If you do have, try

ping us.archive.ubuntu.com

Incase that does not work, try

host -v us.archive.ubuntu.com

If there are any errors in you DNS connection, they'll show up here.


Change lock screen style on gnome classic desktop

Run sudo apt-get install lightdm. If it's already installed, run sudo dpkg-reconfigure lightdm, and choose lightdm. You can still log in to any desktop you've install by selecting the arrow in lightdm and clicking gnome classic.


Btrfs is actually supposed to react to new devices dynamically, through udev calling btrfs device ready/BTRFS_IOC_DEVICE_READY. See /lib/udev/rules.d/64-btrfs.rules. This logic obsoletes btrfs device scan which is inappropriate for a dynamic boot. According to this, Btrfs' messages to udev have a flag to tell when there's enough backing devices to mount the Btrfs filesystem on them.

However, I'm not sure that mountall (an underdocumented piece of software that scans /etc/fstab and calls mount) implements the rest. The solution involves either fixing mountall or hacking up something that could be specific to your system, putting the mount command in /etc/rc.local or a custom udev rule.


snap applications without permissions to write to home directory when using sssd

The issue is due to the user home folder being part of the domain.

$ sudo dpkg-reconfigure apparmor

Then, specify "/home/[DOMAIN]/" as an additional user home directory.
This should resolve the permission issue for all the applications


install ubuntu as a dual boot with windows 7

Go to the Lenovo BIOs/UEFI settings (F1 at power up, or thinkvantage button), and look at the preferences for boot mode.  Lenovo allows booting both ways, but you select which you prefer when both are possible.  Select "legacy" before "UEFI" and your install media will boot in legacy mode, without needing an EFI partition.

In legacy mode, no EFI partition is needed -- ignore any suggestion to create one.  Your new partitions may all be logical partitions within the extended partition.  The installer should create them as needed in the free space.


sulogin cannot read /dev/tty1 permission denied

Make sure your /etc/fstab is all correct and reboot. I would recommend commenting out all lines except the essential ones (by putting # at the beginning of the line) and trying to reboot. If it works, try uncommenting the lines one by one and rebooting between each try to see which lines is the problem.


how can i install adobe flash player 11.tar.gz file on ubuntu 13.04

You don't need to install the tar.gz file.

Following the instructions from How do I install Adobe Flash player? (in a nutshell search and install flash from the Software Centre).


What file managers are available for Ubuntu?

The Best Ubuntu File Managers are

1 Nautilus

This is default in Ubuntu-desktop but other flavors of Ubuntu  can get it with

sudo apt-get install nautilus

The default file manager in GNOME DE too, Nautilus has an intuitive interface and offers features like previews, sorting, three view modes (icons, list, compact), bookmarks. Nautilus can be expanded via plugins and it also supports context menus.

2 Dolphin

This is default in Kubuntu-desktop but other flavors of Ubuntu  can get it with

sudo apt-get install dolphin

Dolphin is the default file manager for KDE focusing on usability. The main features of Dolphin are:

Navigation bar for URLs, which allows to navigate quickly through the file hierarchy
View properties are remembered for each folder
Split of views and tabs are supported
Network transparency
File content previews
Support for version control system plugins
Integrated terminal
Searching for file content and meta information

3 thunar

This is default in Xubuntu-desktop but other flavors of Ubuntu  can get it with

sudo apt-get install thunar

4 Nemo

we can install it with

 sudo apt-get install nemo

5 Double Commander ( new )

sudo add-apt-repository ppa:alexx2000/doublecmd
sudo apt-get update

For gtk version

 sudo apt-get install doublecmd-gtk

for Qt version

sudo apt-get install doublecmd-qt

6 Pcmanfm

sudo apt-get install pcmanfm

7 Konqueror

Konqueror is one of the most advanced file managers for KDE. Thanks to the underlying KDE technologies it can transparently access FTP and SFTP servers, zip files (and other archives), smb (Windows) shares, and even browse and rip audio CDs.

sudo apt-get install konqueror

Update:

OMG! we have so many more! Click here for 20 File managers for Ubuntu


nvidia-smi stops working after reboot ununtu 18.04

This is most probably the nvidia graphics compatibility problem, so you shouldn't use the .run installer. Use the driver from ubuntu graphics ppa, then download the .deb and install cuda-toolkit.


Distorted display after upgrading the kernel to 5.4 on Ubuntu 18.04 32 bit

I just figure that out, but I am not sure whether my method would work for you. My system is Windows10-Ubuntu dual boot system with Ubuntu grub menu for selecting OS.
My environment: Ubuntu 18.04.5 64bit, kernel: Linux 5.4.0-70-generic
machine: Ryzen 7 5800x, rtx2060 super, MSI MAG b550 tomahawk, TPLINK WIFI 6 ax3000 PCIe WIFI card (this WIFI card is the reason I upgrade my kernel from 4.15 to 5.4)
In short, I solve it by installing proprietary driver for graphic cards in recovery mode.
The initial reason I do the upgrade is because kernel 4.15 does not support WIFI 6 and kernel 5 does. So I upgrade my kernel on Ubuntu 18.04 using (https://wiki.ubuntu.com/Kernel/LTSEnablementStack#Ubuntu_18.04_LTS_-_Bionic_Beaver)
sudo apt-get install --install-recommends linux-generic-hwe-18.04 xserver-xorg-hwe-18.04

When I reboot my machine, the screen was distorted with pepper noise pixels and did not response. Seems like it want to show some lines but it met some display problem. I restart my machine and in the grub menu, I select advanced options for Ubuntu and enter recovery mode for kernel 5.4. Just select resume and it just display the desktop correctly! I checked the kernel version, yes it is 5.4 and it was function normally in recovery mode. I added the nvidia PPA and installed proprietary driver 460 in additional drivers GUI. Reboot normally (not recovery mode), it works!
Afterthought: When I tried to install ubuntu 18.04 with bootable usb, I encountered exactly the same problem (pepper noise pixels). But it still displayed some message at that time, which is r8169 unknown chip xid 641. So it is probably related to this?
Hope this post would helps somebody out. Good luck with Linux!


How to add percent and remained time of download by aria2c via Sysmonitor Indicator?

I am fairly sure there isn't an indicator for aria2. You can however integrate aria2 with uGet and get an indicator. The uGet indicator doesn't have a progress bar but it does have indication of currently downloading and completion.

http://uGetdm.com


No sound from build-in soundcard after upgrading to ubuntu 16.04

I had the same issue with Ubuntu 16.04 in my acer aspire e15 laptop. One person suggest me to upgrade to 18.04, and it worked!


alt+tab, alt+`, show titles, switching between, open windows, example using Chrome

in ubuntu 16.04, alt+tab switches between [all open applications (window groups) - and not all windows] (has a very long delay to switch between windows within an app) -- and you cannot see all the open windows like you can in win10

The delay can be avoided if you use Alt+` once you've positioned the highlight of Alt+Tab  on the appropriate window group. For instance, you switch over to chrome group and immediately initiate switching with Alt+` . On most keyboards Tab and ` are close so I won't buy an excuse that those keys are too far to reach or it's two keys to type - people spend far more keystrokes on useless stuff ( like this sentence).

  how do you use alt+tab or any easy shortcut to SEE all open windows, and switch between [all open windows]

Use Super(aka Windows key)+W. This will open expo of all open windows. You can use either mouse or arrow keys to select the one you want.

All window titles cannot be shown in the expo,  only of the selected window. The way to get around this is to use mouse or arrow keys to highlight window, thus revealing its title.

  how do you use alt+tab or alt+` to switch between [all open windows - that are NOT minimised]?

That's not available. You can however put a feature request to Unity (which is the desktop name Ubuntu uses) developers.

  workspaces can be a possible solution IF it's easy to open chrome windows in different workspaces, and if workspaces reaches the goal presented

Yes, it's possible to do the same thing I described above ( Atl+Tab and then Alt++` ) but with workspaces the shortcut is Ctrl+Alt+Tab. The rules here change however - you can only show all chrome windows with Alt++`, but switching between them is still Tab while holding Ctrl+Alt

  I'm very surprised that ubuntu has these basic limits

If you're using Windows as standard - sure , these might seem as limits. Look at Ubuntu's work flow from a different perspective. You already figured out there's switcher for window groups. This is useful when you have tons of applications open - you don't want to switch between 35 windows just to reach the one you want. Got the Chrome group ? Got your window ? boom - done. So instead of looking at these as limitations, think of this as different standards.