During the installation, I was asked if I wanted GRUB to be installed on the harddrive to simplify dual boot. Somehow it was installed on the USB instead of the harddrive. Because of this, every time I tried booting from the USB, it bypassed the live-usb and kept on booting the server instead.

To solve it I just created a new live-usb.


SSH cannot find user directory and fails to login

The way a simple SSH command work is as follows:

ssh user_name@host

If you omit user_name and just run ssh host it will assume that you mean the same user that is currently logged in to your machine. Let's say your login is jdoe, then it will become equivalent to ssh jdoe@host.

Please note that the user that you are logging in as must be a valid user to be logged on to that computer. With some exceptions, that probably do not apply in this case, you should be able to go to that machine and log in locally by using that particular user name and the password that you have entered.

If you control both machines and wish to create a user on the remote one, you need to run:

sudo adduser user_name

Just change user_name to the name that you wish your user to be, once again if that is jdoe you would type sudo adduser jdoe. You will be asked for password, name of the user, etc.

Alternatively you can use useradd command, but it is a lower level command, and should probably be avoided. Especially if other stuff that i wrote here sounds new to you.

There is no need to create the home directory yourself, it will be created for you.


How to fix my monitor which is always out of range

Since the cause of the problem might have been a sudden power outage, I'd try checking the file system for errors. Boot from the CD again, open a terminal window and run sudo fdisk -l (that's a small L, not one) to identify the Ubuntu partition. The output will look something like this:

~$ sudo fdisk -l

Disk /dev/sda: 80.0 GB, 80026361856 bytes
255 heads, 63 sectors/track, 9729 cylinders, total 156301488 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x4d384d37

   Device Boot      Start         End      Blocks   Id  System
/dev/sda1   *          63    57978584    28989261    7  HPFS/NTFS/exFAT
/dev/sda2        57978880   156301311    49161216   83  Linux

...and /dev/sda2 is the Ubuntu partition in my case. If there is more then one, and you aren't really sure which one to check, check them all, it shouldn't get any worse.

Now type sudo fsck -vy /dev/sdXY, substituting correct credentials for X and Y.


Juju Subordinate Charm: Vault mysql-router

I stumbled today upon the same problem. I was following this tutorial: https://docs.openstack.org/project-deploy-guide/charm-deployment-guide/latest/install-openstack.html. When I looked into the logs in the /var/log/juju directory on the vault-mysql-router/0 machine (juju ssh vault-mysql-router/0) I saw that there was no package candidate in the repository. My guess is that juju by default deploys bionic ubuntu, for chich mysql-router is not available (https://jaas.ai/mysql-router shows some other series but not bionic).
I restarted the whole installation by destroying the controller and bootstrapping it using --bootstrap-series focal switch. Later on for each deploy I added --series focal which deployed all the charms using the newest Ubuntu LTS. For that the mysql-router installed correctly. This also solves the problem where some LXD containers had focal series whereas rest had bionic (which is no good according to the documentation).
I do not know however if whole installation will work. I'm in the middle so far (after the RabbitMQ step) and so far it looks good. I had to follow the steps described in https://docs.openstack.org/project-deploy-guide/charm-deployment-guide/latest/app-certificate-management.html to generate self signed CA certificate and reissue them as ovn didn't want to get one even thou the vault was unlocked and keystone got its certificate.


How to make speech-dispatcher work with variables?

I think you mean this:

spd-say "$(date)"


Install the same version of ubuntu on each old computer.
Use the same account name and setup ssh public key auth on each.
Install distcc following the instructions here: https://code.google.com/p/distcc/

That gets you "power to compile" exactly as you asked for.

Using the storage as a big nas is a bit more challenging. There are many approaches you could take. You could use cephfs or glusterfs or another distributed file system, but those tend to be complex and have a steep learning curve and take some time to configure and maintain.

Most nas devices expose things with SMB. You could use samba's DFS features to transparently redirect clients which connect to some head node, to various other nodes, depending on the path used. Its not really unified storage, but it may suit your needs.


How to change the workspace navigation keyboard shortcuts?

Use compizconfig-settings-manager (ccsm). The package to install this is calles compizconfig-settings-manager and in software center it can be found on compiz' details page.
In ccsm edit the settings for the "Desktop Wall". There you can adjust the keybindings you want to modify.


How can I make audio input work with Intel NUC5i3RYK

I managed to solve the problem by using a simple splitter, similar to this one: http://cdn3.volusion.com/yuyf4.pmrj2/v/vspfiles/photos/KM-IPHONE-2TRS-A22-2.jpg
For a reason that is still unknown, my NUC did not want to accept input when I was connecting the microphone cable directly to its jack socket. I simply connected it through that additional splitter cable and voila :). It works :).


Script to find executable based on extension of a file?

I grabbed a Linux expert in the office and we found a reasonable solution:

#!/bin/bash
EXTENSION=$1
SAMPLENAME=$HOME/~webdavhelpersample.$EXTENSION
touch $SAMPLENAME
CURMINE=$(xdg-mime query filetype $SAMPLENAME)
rm $SAMPLENAME
CURDSK=$(xdg-mime query default $CURMINE)

if [ -f /.local/share/applications/$CURDSK ]; then
    TRUEDSK=/.local/share/applications/$CURDSK
elif [ -f /usr/local/share/applications/$CURDSK ]; then
    TRUEDSK=/usr/local/share/applications/$CURDSK
elif [ -f  /usr/share/applications/$CURDSK ]; then
    TRUEDSK=/usr/share/applications/$CURDSK
else
    echo "Sorry no executable found for $1"
    exit 1
fi

WHATTODO=$(grep "^Exec" $TRUEDSK | head -1)
echo $WHATTODO

Once we figured that there are only 3 locations for the desktop files it was not hard anymore.


Newest kernel 3.13.0-33 causes boot problems

Open Terminal and Type :- dpkg --list | grep linux-image After this It will show all linux kernels installed in your system.

Now type :- sudo apt-get purge linux-image-x.x.x.x-generic Replace x.x.x.- With the kernel you want to remove

eg:-

 sudo apt-get purge linux-image-3.13.0-33-generic

After Deleting kernel Type :- sudo update-grub and reboot


Why is the minimum video memory for a virtualbox machine so large?

Simple Answer: Yes.

If you experience lag just adjust it. Even though I use just the console I adjust it to way more than 1MB just because im always flying all over the place.

The default recommended video memory for SERVERS on VB is ~9MB


How to make a live Ubuntu 18.04 USB with a persistent storage of more than 4GB

I suggest that you try mkusb. It can create a persistent live drive with a casper-rw partition almost automatically (it is an option in the graphical user interface).

The size of the casper-rw partition is only limited by the size of the USB drive (and the size of a 'competing' usbdata partition (for exchange of data with Windows) that you may give drive space). You can select 100% (of the remaining space, when the system files are installed) for persistence and use most of the drive space for the casper-rw partition.

If you run standard Ubuntu live, you need an extra instruction to get the repository Universe. (Kubuntu, Lubuntu ... Xubuntu have the repository Universe activated automatically.)

sudo add-apt-repository universe  # only for standard Ubuntu

sudo add-apt-repository ppa:mkusb/ppa  # and press Enter
sudo apt-get update
sudo apt-get install mkusb mkusb-nox usb-pack-efi

Links

help.ubuntu.com/community/mkusb

help.ubuntu.com/community/mkusb/persistent

Quick start manual mkusb version 12 alias mkusb-dus


Your processor does not appear to be official Ubuntu certified Hardware, but that doesn't mean Ubuntu won't run on it. You may want to do a Google search with your laptop name and "Ubuntu installation" to get tips and tweaks for installation on your specific Laptop. You should Download Ubuntu x64 and put it onto usb stick. Boot to the usb stick and select "Try Ubuntu". This will let you run Ubuntu without installing it to your machine. Test it out and make sure everything works. If it works well in this mode, it will probably run well when it is installed. To install double click the "Install Ubuntu" shortcut on the desktop. The Ubuntu installer will step you through the installation of Ubuntu.


unable to remove the lubuntu desktop environment

Run those commands:

sudo apt-get purge lxde
sudo apt-get autoremove lxde
sudo apt-get purge lubuntu-desktop
sudo apt-get autoremove lubuntu-desktop

If the above doesn't solve your ptoblem totally then try this command:

sudo apt-get remove abiword abiword-common abiword-plugin-grammar abiword-plugin-mathview ace-of-penguins audacious audacious-plugins audacious-plugins-data blueman catfish chromium-browser chromium-browser-l10n chromium-codecs-ffmpeg elementary-icon-theme fonts-lyx galculator gdebi gdebi-core gecko-mediaplayer giblib1 gnome-desktop-data gnome-icon-theme-full gnome-mplayer gnome-system-tools gnome-time-admin gnumeric gnumeric-common gnumeric-doc gpicview gtk2-engines-pixbuf guvcview hardinfo indicator-application-gtk2 leafpad libaacs0 libabiword-2.9 libass4 libaudclient2 libaudcore1 libavcodec53 libavformat53 libavutil51 libbinio1ldbl libbluray1 libbs2b0 libcddb2 libcolamd2.7.1 libcompfaceg1 libcue1 libdca0 libdirectfb-1.2-9 libenca0 libept1.4.12 libexo-1-0 libexo-common libexo-helpers libfaad2 libfluidsynth1 libfm-data libfm-gtk-bin libfm-gtk-data libfm-gtk3 libfm3 libgdome2-0 libgdome2-cpp-smart0c2a libglade2-0 libgmlib0 libgmtk0 libgmtk0-data libgoffice-0.8-8 libgoffice-0.8-8-common libgsf-1-114 libgsf-1-common libgsm1 libgtkmathview0c2a libgtkspell0 libguess1 libid3tag0 libimlib2 libindicate-gtk3 libjpeg-progs libjpeg-turbo-progs liblink-grammar4 libloudmouth1-0 libmenu-cache1 libmms0 libmodplug1 libmowgli2 libmp3lame0 libmpg123-0 libmusicbrainz3-6 libnet-dbus-perl libobrender27 libobt0 libonig2 liboobs-1-5 libopts25 libots0 libpisock9 libpostproc52 librarian0 libresid-builder0c2a libschroedinger-1.0-0 libsdl1.2debian libsidplay2 libswscale2 libtidy-0.99-0 libtie-ixhash-perl libts-0.0-0 libuniconf4.6 libva1 libvdpau1 libvpx1 libvte-common libvte9 libwebcam0 libwv-1.2-4 libwvstreams4.6-base libwvstreams4.6-extras libxfce4ui-1-0 libxfce4util-bin libxfce4util-common libxfce4util6 libxfconf-0-2 libxml-parser-perl libxml-twig-perl libxml-xpath-perl libxvidcore4 lightdm-gtk-greeter link-grammar-dictionaries-en lm-sensors lp-solve lubuntu-artwork lubuntu-artwork-12-10 lubuntu-core lubuntu-default-settings lubuntu-desktop lubuntu-icon-theme lubuntu-lxpanel-icons lubuntu-software-center lxappearance lxappearance-obconf lxinput lxkeymap lxlauncher lxmenu-data lxpanel lxpanel-indicator-applet-plugin lxrandr lxsession lxsession-data lxsession-edit lxshortcut lxtask lxterminal mplayer2 mtpaint ntp obconf openbox openbox-themes pcmanfm pidgin pidgin-data pidgin-libnotify pidgin-microblog plymouth-theme-lubuntu-logo plymouth-theme-lubuntu-text python-pysqlite2 python-support python-xklavier rarian-compat scrot sylpheed sylpheed-doc sylpheed-i18n sylpheed-plugins synaptic system-tools-backends transmission tsconf uvcdynctrl uvcdynctrl-data wvdial xfburn xfce-keyboard-shortcuts xfce4-notifyd xfce4-power-manager xfce4-power-manager-data xfconf xfonts-100dpi xpad xscreensaver xscreensaver-data && sudo apt-get install ubuntu-desktop && sudo /usr/lib/lightdm/lightdm-set-defaults -g unity-greeter


If the whole partition were encrypted, resizing would be complicated, but that's not the case. It's perfectly safe to resize it.


How do I know if my web camera is linked to Ubuntu?

Use lsusb to list devices, assuming the camera is listed you could use cheese (it should be in the repos) to test that it is working


When will packages uploaded to PPA by dput available?

dput ppa:warlock/spell (or whatever)
Wait for email from Launchpad, whose subject should say (hopefully):

[PPA warlock-spell] [ubuntu/precise] oohitsmagic 1.2.3-4~ppa1precise1 (Accepted)

or if you messed something up:

[PPA warlock-spell] oohitsmagic_1.2.3-4~ppa1precise1_source.changes rejected
If the upload is successful, then you can check the status on the PPA page, where it should say 2 packages waiting to build (or similar), and you can click on them to see what the approximate wait-time is before the builds for the different architectures begin.
Unless you want to keep pressing F5 (hey, I did that for my first PPA upload :), go get a coffee, take a nap, etc., but keep your eye out for the Launchpad email sent if your build fails, with a subject like:

[Build #1234567] i386 build of oohitsmagic 1.2.4-4~ppa1precise1 in ubuntu precise RELEASE (warlock-spell PPA)
If the build succeeds, that will be show in the status bar for your PPA on the right; note that even after this, you must wait for the binaries to be published in the PPA before you can go around apt-getting them (a green gear means wait, a check mark means published).


My npm version is 5.0.3 and I have the same problem when I use any npm command:

The command is working fine but this code keeps showing up for no apparent reason.  I've updated from 5.0.3 to 5.2.0 with these commands:

sudo chown -R $USER:$(id -gn $USER) /home/sagar/.config

npm install -g npm or npm i -g npm.

Now npm is working fine.


How do I get quick lists in unity shipped in 11.10?

One way to help with this is to file a wishlist bug on the component that you want a static quicklist for and include the .desktop file. Then tag the bug with quicklist so we can keep track of the bugs.

We're tracking the status of these bugs on this page.

For programs that might not live in Launchpad a friendly wishlist request in their bug tracker with the snippet from the .desktop file could work.

However I only recommend doing that for the "long tail" of little programs that people are using. Large programs that we ship by default, like Nautilus and Firefox, will need support for dynamic playlists instead.

So for example we can't just ship a .desktop for Nautilus with the handy shortcuts. We need Nautilus to support any shortcut the user defines in the program so that it's always showing the user's favorites, even if the change them. For browsers they'll need to do like "the last X websites" or "last X tabs you closed" or whatever their design criteria is.

However for most little tools a static quicklist can be a nice little bit of Unity integration so contacting app authors and showing them the work you've done would be quite useful.


Installing Multiple OS and prepare the Partitioning

It is possible to have 3 or more operating systems on your HD.

You must first of all install windows, and after that install the other Linux operating systems (in any order you prefer).

When you install Ubuntu, Mint or Fedora, they also install grub, the multiboot boot-loader, that checks if there are already one or more operating systems and allows the multi-boot.

If you install windows after linux, the boot-loader is overwritten by windows and you can't access to linux again, but only to windows.

When you install linux for the first time, there is the possibility to manually manage the partitions, so you can:

resize the windows partition (it has an NTFS file system, or FAT for older versions)
add one or more partitions for linux (you should choose the "ext4 with journaling" file system).
You must also add a SWAP partition, that is needed by linux systems. This partition should be at least as big as the RAM memory of your system.

Summarizing, you need:

1 swap partition (at least as big as your RAM memory)
1 ext4 partition for every linux OS you want to install
1 ntfs partition for windows
(optional) 1 ntfs partition for keeping data shared among different operating systems (as suggested by oldfred)

If you want to prepare the partitions at the begininning, you can use gparted in linux or partition magic in windows (but I suggest you to do it in linux).

I think the easiest way is to create a USB pendrive with the linux distribution, start you pc from this pendrive and start the installation process, during which you can create all the partitions you want of the size you want.


How can I avoid the PC from shutting down from heat

You cannot change the maximum temperature for hardware components.

Here is a list of useful application indicators for Ubuntu 11.10.

You should install CPUFreq (to manually lock your CPU to a lower value, to be sure your temperatures are not growing) and Hardware Sensors Indicator (to see the many temperatures of your system components).


I had issues with shadows and speed when I upgraded from 11.04
Runs much better after a clean install. I absolutely recommend you try this instead of an upgrade.


no sites loading in mozilla : Secure connection failed issue

I did the steps as mentioned in my comment above (i.e. in about:config, I made " security.ssl.enable_ocsp_stapling " to false. But this did not resolve the issue in my machine (Ubuntu 15.10 and firefox 47.0).

So then, from the help menu in Firefox, I just did "Restart with Add ons Disabled." and now I got back to a normal functioning Firefox.

If the above does not work for you below are some pages that may be of help

https://support.mozilla.org/en-US/questions/1081813
https://support.mozilla.org/en-US/questions/1073420
https://support.mozilla.org/en-US/questions/1081813


How to install Nvidia 319.12 driver on an optimus system

Try installing the new beta version of Nvidia 319.12 with bumblebee.

sudo apt-get remove bumblebee-nvidia nvidia-current nvidia-settings
sudo apt-get install bumblebee-nvidia nvidia-319 nvidia-settings-319

Link http://orkultus.wordpress.com/2013/04/20/how-to-nvidia-319-12-drivers-in-ubuntu-based-systems-with-bumblebee/


What do I select for “GRUB install devices” after an update on a VM?

Assuming you're not using UEFI, and I see no reason as to why you should be. Also assuming you didn't set it up in some fancy pancy way originally, then yes, the first option is the correct one. By selecting /dev/sda it will be installed to the MBR of /dev/sda, which a BIOS should be able to boot.


I installed libxft, libfreetype, libgtk,libm17n and recompiled emacs. This linked things up!


Can 'avahi' handle IP address lookups as well as host name lookups?

Yes, avahi supports reverse IP address lookups for the .local names that are registered on the local network. However, most of the commands for performing test queries contact DNS servers directly without using avahi. In order to confirm that this is working at the command line, you have to use the getent hosts command instead of nslookup, dig, or host.

For example, you can look up an IP address using the following commands:

$ nslookup 192.168.0.1
$ dig -x 192.168.0.1
$ host 192.168.0.1
$ getent hosts 192.168.0.1

Only the getent hosts command will return the corresponding name because it is the only command that uses avahi to perform the reverse lookup.

(Actually, this also applies to looking up names, but it is usually simpler to just type ping hostname.local which performs a name lookup using DNS or avahi and checks connectivity at the same time.)


Some claim on the internet that persistence reduces lifespan of the USB stick

Is this true?

Yes it is true, particularly compared to a cloned live-only boot drive with a read-only iso9660 file system, which is never written until a new Ubuntu system is flashed into it. I think it is also true, compared to a standard storage device, where you store files manually.

If Yes, Why is this true?

The flash memory cells of USB sticks have a limited number of write cycles to the expected end of life, and this number is lower than those of an SSD and the magnetic memory of a hard disk drive.
Persistence in an installed system as well as in a persistent live drive makes it possible to write to the memory.

A standard installed system writes a lot, but the writing can be reduced.
A persistent live system writes too, but it is designed so that it writes less to the USB stick than an installed system. It works with a file system, that resides in RAM.

Anyway, it is important to backup the persistent data regularly, if you want to avoid loss of data.

How reduced is the lifespan?

It is difficult to say how much the lifespan is reduced. It depends on the number of write cycles, and the time can differ a lot between use cases. I have persistent live drives that have been working for years, but I use them carefully. Only one of my USB pendrives has failed, and very early (not because of too many write cycles).

But I know of several cases, where SD memory cards have failed, I think because of excessive wear, when they have been used as system drives in Raspberry Pi computers. These are normally installed systems, tweaked to reduce the wear. SD cards have the same kind of memory cells as USB sticks.
Also, the quality of the memory cells and the wear leveling methods have improved over the years, so warnings that are several years old would be exaggerated now.

Links,

Pendrive lifetime
Installed system - Final system tweaks
Boot Ubuntu from external drive
Can't format my usb drive. I have already tried with mkdosfs and gparted - Analysis of the problem


Change color scheme for xfce4 terminal manually

XFCE4 terminal stores user preferences in $XDG_CONFIG_HOME/xfce4/terminal/terminalrc (typically, ~/.config/xfce4/terminal/terminalrc - might not exist if you haven't changed any preferences). I found that XFCE4 Terminal watches this file and reloads settings when it changes, so you can write to this file to change settings.

However, there is no single entry you can edit to change the colours. The various palettes are actually a set of settings. For example:

$ cat /usr/share/xfce4/terminal/colorschemes/solarized-dark.theme
[Scheme]
Name=Solarized (dark)
Name[bg]=Златисто (тъмно)
Name[fr]=Solarisé (foncé)
Name[nl]=Overbelicht (donker)
Name[th]=ในแสงแดด (มืด)
Name[uk]=Золотистий (темний)
ColorForeground=#839496
ColorBackground=#002b36
ColorCursor=#93a1a1
TabActivityColor=#dc322f
ColorPalette=#073642;#dc322f;#859900;#b58900;#268bd2;#d33682;#2aa198;#eee8d5;#002b36;#cb4b16;#586e75;#657b83;#839496;#6c71c4;#93a1a1;#fdf6e3
ColorBold=#93a1a1
ColorBoldUseDefault=FALSE

And terminalrc will look like:

$ cat .config/xfce4/terminal/terminalrc
[Configuration]
ColorForeground=#839496
FontName=Ubuntu Mono 12
ColorBackground=#002b36
ColorCursor=#93a1a1
ColorBold=#93a1a1
ColorBoldUseDefault=FALSE
ColorPalette=#073642;#dc322f;#859900;#b58900;#268bd2;#d33682;#2aa198;#eee8d5;#002b36;#cb4b16;#586e75;#657b83;#839496;#6c71c4;#93a1a1;#fdf6e3
TabActivityColor=#dc322f
TabActivityColor=#dc322f

As can be seen, there's no way to easily identify which palette the colours came from.

Scripting this doesn't seem safe, but here's an inefficient attempt:

#! /bin/bash
if ! [[ -f /usr/share/xfce4/terminal/colorschemes/$1.theme ]]
then
    echo "No such colorscheme: $1"
    exit 1
fi
cd ~/.config/xfce4/terminal
# strip settings from any themes
grep -Fxvf <(cat /usr/share/xfce4/terminal/colorschemes/*.theme) terminalrc > .terminalrc.tmp
grep -v -e Name -e Scheme "/usr/share/xfce4/terminal/colorschemes/$1.theme" >> .terminalrc.tmp
cp terminalrc terminalrc.bak
mv .terminalrc.tmp terminalrc

Copy this to somewhere in your PATH (for example, ~/bin/xfce-color-switch). Then:

$ xfce4-color-switch dark-pastels

$ xfce4-color-switch solarized
No such colorscheme: solarized
$ xfce4-color-switch solarized-dark

You'll have to remember colorscheme names for this, but I'll add instructions on how to add tab-completion once I figure them out.


Booting to CD on the Lenovo G50-80

The installed OS (in this case Ubuntu) won't affect booting to the CD.  This is a function of the BIOS that happens before loading the OS.

This are steps from the Lenovo Forum for booting to the CD/DVD, and Entering Lenovo G5-80 Bios Setup (Youtube).  There is more than one method.  You may have performed a different method when you booted to the DVD to install Ubuntu.

It appears there is a Lenova Key on the left side of the Tablet to go into the boot menu.  The Youtube video shows the option for Selecting to make the Pendrive a bootable option.  You can use this as variants for selecting to boot to the DVD.  Further details can come from browsing the boot options you see while in the BIOS, along with Manufacturer's support.

Software Center Issues

Reinstalling Ubuntu might not be the best resolution.  Whatever problem you're having could come back to the new install.  You might best work with resolving the issue.

There are frequent glitches with the new Ubuntu Default Software Center.  I have experienced it on a number of installs.  On each occasion it was resolved with this commandline:

$ rm -r ~/.local/share/gnome-software

Other details of the issues with the Software center can be found at: Gnome Software Center Not Loading


"Hidden, superfluous data" because of improper mounting of home directory

Encryption does not double your disk usage, removing the encryption would make no difference. Some disk usage apps report encrypted data wrongly or confusingly, the best way to view your actual usage is with:

df -h


Maybe (some of) your custom keyboard shortcuts conflict with shortcuts which are already 'taken' by your system. Try changing your custom keyboard shortcuts so they are unique.


This behavior is caused by a notorious appmenu-qt5 bug. The bug report is here. It sets an environment variable for qt applications and this causes many applications menu item to be problematic in Unity. VLC is one of them.
The environment variable is QT_QPA_PLATFORMTHEME and is set in the file /etc/profile.d/appmenu-qt5.sh.
Workaround
To workaround this bug, You can unset this variable and start VLC then. From terminal you can use this command to start VLC without this bug.
env QT_QPA_PLATFORMTHEME='' vlc

As a permanent fix, first copy the vlc.desktop file to ~/.local/share/applicatons/
cp /usr/share/applications/vlc.desktop ~/.local/share/applications/

and then edit the line starting with EXEC to this line below
Exec=env QT_QPA_PLATFORMTHEME='' /usr/bin/vlc --started-from-file %U

Save the file. Now if you start VLC, the shortcut will work from start.
Update
As reported by Jonathan Y, it seems unsetting UBUNTU_MENUPROXY environment variable works too! So, you can use un-setting this variable in .desktop file.
Exec=env UBUNTU_MENUPROXY='' /usr/bin/vlc --started-from-file %U


Boot with a Live Ubuntu Disc
Mount the partition/s with Ubuntu file system, on /mnt
Example

sudo mount /dev/sdxx /mnt
sudo mount /dev/sdxy /mnt/boot
sudo mount /dev/sdxz /mnt/boot/efi

Where sdx=disk, sdxx="/" partition, sdxy="boot" partition,sdxz="efi" partition

then run

for i in /dev /dev/pts /proc /sys /run; do sudo mount -B $i /mnt$i; done
sudo chroot mnt

Most importantly, since you have lost your /boot/grub/efi and may be /boot/grub/efi  also.

Find your boot type

[ -d /sys/firmware/efi ] && echo "EFI boot on HDD" || echo "Legacy boot on HDD"

If internet problem.

echo "nameserver 8.8.8.8" >/etc/resolv.conf

or

cp /mnt/etc/resolv.conf /etc/resolv.conf

For legacy/bios boot

apt install --reinstall grub-pc grub-common

For UEFI(efi) boot

apt install --reinstall grub-common grub-efi grub-efi-amd64 grub-efi-amd64-bin

And

grub-install /sdx # no apt infront

Now run

dpkg -S /boot
sudo dpkg --audit

to find the packages needed. Install the packages.

Then

apt --fix-missing install
update-initramfs -u
update-grub

and

exit
for i in /sys /proc /dev/pts /dev; do sudo umount /mnt$i; done

Unmount mounted partitions.

Example:

sudo umount /mnt/boot/efi
sudo umount /mnt/boot
sudo umount /mnt
sudo reboot

For errors after rebooting.

sudo dpkg --configure -a


Is there a preinstalled or automatic firewall?

Ubuntu has a firewall included in the Kernel, and is running by default. What you need to manage this firewall are the iptables. But this are complicated to manage, so you can use UFW (uncomplicated firewall) to configure them. But UFW is still something hard for normal users, so what you can do is install GUFW  that is just a graphical front end for UFW.

If you use GUFW, the first time you will see at the bottom of the window 'Disabled Firewall'. But this is not true, your firewall is already running. This enable/disable message refers to the rules set with UFW, not to the firewall.

If you don't believe me open a terminal and write

sudo iptables --list --verbose

Try this with GUFW enabled and disabled. You will see that the only diferences will be the rules you set with GUFW.

Information from this Ubuntu Forums thread


To achieve 3.1 GHz Turbo Boost - you could only utilize one quarter of your CPU.

This does not nearly compensate performance-wise for a well written program that would utilize all cores. While it's a nice feature, it's usually not a performance boost on top of the stock performance of all cores being completely utilized.

You are mixing things up:

  SpeedStep is a trademark for a series of dynamic frequency scaling technologies (codenamed Geyserville and including SpeedStep, SpeedStep II, and SpeedStep III) built into some Intel microprocessors that allow the clock speed of the processor to be dynamically changed (to different P-states) by software.

http://en.wikipedia.org/wiki/Intel_speedstep

  Intel Turbo Boost is a technology implemented by Intel in certain versions of their Nehalem- [...] Haswell-based CPUs, including Core i5 and Core i7, that enables the processor to run above its base operating frequency via dynamic control of the CPU's clock rate.

http://en.wikipedia.org/wiki/Intel_Turbo_Boost

  All the info in /proc/ and /sys/device/system/cpu/ is always limited to regular frequencies by design; see https://kernel.org/doc/Documentation/cpu-freq/boost.txt

comment by Class Stacker on question Is Turbo Boost Working?

  Some CPUs support a functionality to raise the operating frequency of
  some cores in a multi-core package if certain conditions apply, mostly
  if the whole chip is not fully utilized and below it's intended thermal
  budget. The decision about boost disable/enable is made either at hardware
  (e.g. x86) or software (e.g ARM).

https://kernel.org/doc/Documentation/cpu-freq/boost.txt

Simply put, your i5 CPU decides for itself if it applies boost or not and Linux by default doesn't care much about providing accurate and detailed information for this.


If you have access to that file over nautilus, or whatever you are using, just double-click your .bashrc and an editor will open. You may need to hit CTRL+H first, to unhide hidden files.

This is the default Ubuntu .bashrc, found on GitHub. Just replace yours with this one. Then you can readd you changes and see what causes the error.

    # ~/.bashrc: executed by bash(1) for non-login shells.
# see /usr/share/doc/bash/examples/startup-files (in the package bash-doc)
# for examples

# If not running interactively, don't do anything
[ -z "$PS1" ] && return

# don't put duplicate lines in the history. See bash(1) for more options
# ... or force ignoredups and ignorespace
HISTCONTROL=ignoredups:ignorespace

# append to the history file, don't overwrite it
shopt -s histappend

# for setting history length see HISTSIZE and HISTFILESIZE in bash(1)
HISTSIZE=1000
HISTFILESIZE=2000

# check the window size after each command and, if necessary,
# update the values of LINES and COLUMNS.
shopt -s checkwinsize

# make less more friendly for non-text input files, see lesspipe(1)
[ -x /usr/bin/lesspipe ] && eval "$(SHELL=/bin/sh lesspipe)"

# set variable identifying the chroot you work in (used in the prompt below)
if [ -z "$debian_chroot" ] && [ -r /etc/debian_chroot ]; then
    debian_chroot=$(cat /etc/debian_chroot)
fi

# set a fancy prompt (non-color, unless we know we "want" color)
case "$TERM" in
    xterm-color) color_prompt=yes;;
esac

# uncomment for a colored prompt, if the terminal has the capability; turned
# off by default to not distract the user: the focus in a terminal window
# should be on the output of commands, not on the prompt
#force_color_prompt=yes

if [ -n "$force_color_prompt" ]; then
    if [ -x /usr/bin/tput ] && tput setaf 1 >&/dev/null; then
    # We have color support; assume it's compliant with Ecma-48
    # (ISO/IEC-6429). (Lack of such support is extremely rare, and such
    # a case would tend to support setf rather than setaf.)
    color_prompt=yes
    else
    color_prompt=
    fi
fi

if [ "$color_prompt" = yes ]; then
    PS1='${debian_chroot:+($debian_chroot)}\[\033[01;32m\]\u@\h\[\033[00m\]:\[\033[01;34m\]\w\[\033[00m\]\$ '
else
    PS1='${debian_chroot:+($debian_chroot)}\u@\h:\w\$ '
fi
unset color_prompt force_color_prompt

# If this is an xterm set the title to user@host:dir
case "$TERM" in
xterm*|rxvt*)
    PS1="\[\e]0;${debian_chroot:+($debian_chroot)}\u@\h: \w\a\]$PS1"
    ;;
*)
    ;;
esac

# enable color support of ls and also add handy aliases
if [ -x /usr/bin/dircolors ]; then
    test -r ~/.dircolors && eval "$(dircolors -b ~/.dircolors)" || eval "$(dircolors -b)"
    alias ls='ls --color=auto'
    #alias dir='dir --color=auto'
    #alias vdir='vdir --color=auto'

    alias grep='grep --color=auto'
    alias fgrep='fgrep --color=auto'
    alias egrep='egrep --color=auto'
fi

# some more ls aliases
alias ll='ls -alF'
alias la='ls -A'
alias l='ls -CF'

# Add an "alert" alias for long running commands.  Use like so:
#   sleep 10; alert
alias alert='notify-send --urgency=low -i "$([ $? = 0 ] && echo terminal || echo error)" "$(history|tail -n1|sed -e '\''s/^\s*[0-9]\+\s*//;s/[;&|]\s*alert$//'\'')"'

# Alias definitions.
# You may want to put all your additions into a separate file like
# ~/.bash_aliases, instead of adding them here directly.
# See /usr/share/doc/bash-doc/examples in the bash-doc package.

if [ -f ~/.bash_aliases ]; then
    . ~/.bash_aliases
fi

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


How to permanently save the content of /etc/resolv.conf

If you have # This file is managed by man:systemd-resolved(8). Do not edit., at the top of the file, then you can edit /etc/systemd/resolved.conf.
It's not the same syntax as /etc/resolv.conf, but man resolved.conf will help you.
Once the file is saved:
sudo systemctl restart systemd-resolved
And check that the /etc/resolv.conf is updated.


What file permissions should I set on web root?

I would suggest changing the group of your webroot to www-data, the user used by nginx and also php5-fpm.

For example:

sudo chown -R "$USER":www-data /webdirectory
sudo chmod -R 0755 /webdirectory

where my-user is your own account (which enables you to put the files easy in your webroot without sudo).


Just go ahead. You will be fine.

  4gb ram, 500gb disk, Pent D 3.2 ghz

Pretty enough to run windows or any other os  as Virtual Machine.


Boot error - [22,874755] Ext4-fs (sda2): Unrecognized mount option "x-gvfs-name=Ubuntu" or missing value

Looks like a bug in the disk utility.  It seems to have added an invalid option to your /etc/fstab.  Edit the file and remove the goofy "x-gvfs-name=Ubuntu" part:

mount -o remount,rw /
nano /etc/fstab

Edit, and save

reboot


how can i install Boost 1.55 on Ubuntu 15.10?

This can be really bad for your system.
The best thing to do is to clone the source code and compile it yourself.

(it doesn't look that hard: https://github.com/Aloshi/EmulationStation)

But if for some reason you really want to install an old version of libboost you can do it that way:
(I really don't recommend doing that unless you know what you're doing, you can damage your system)
Download from here the packages suitable for your OS:
http://archive.ubuntu.com/ubuntu/pool/main/b/boost1.55/

Ror 64bit download libboost1.55-dev_1.55.0+dfsg-3ubuntu2_amd64.deb  For 32bit download libboost1.55-dev_1.55.0+dfsg-3ubuntu2_i386.deb
If you run something else download libboost1.55-doc_1.55.0+dfsg-3ubuntu2_all.deb


Official support of Ubuntu 16.04 for raspberry pi 3

Here you can find info related ti the solution: Ubuntu arm64/AArch64
on wiki.ubuntu.com

  To check your chip:

cat /proc/cpuinfo

  There is a config.txt entry to make the ARM start in 64-mode (otherwise 32-bit mode is used):

arm_control=0x200

  (This will fail to boot unless you provide a kernel compiled for 64-bit mode) 64 bit versions of the linux-raspi2 kernels were introduced in Ubuntu 16.10 (Yakkety Yak).

  The generic arm64 linux kernels can also be used with a suitable bootloader. For example, the Zesty mini.iso can be booted with a u-boot-UEFI-grub2 combination from SuSE for example.


Blank screen after resuming from suspend state on Ubuntu 16.04 (issue started after installing Nvidia Drivers)

Found many posts but could not find any solution as of now.

Answering my own question, I am currently using a work around using bumblebee. This might be useful to those who are still facing this issue.

Open nvidia-settings (open terminal and type nvidia-settings)
Go to Prime Profiles tab and switch to Intel graphics
Reboot the system
Follow this link to install and setup bumblebee link
Whenever you need to run a program which requires GPU hardware, include "primusrun" ahead of the command (eg., primusrun ./deviceQuery)

This brings another issue for me, whenever I suspend my system and after resuming bumblebee can not locate GPU resources.
Currently trying to solve this one.


rfkill does not work for all the devices listed

If you remove acer-wmi, does your wireless come to life?

    sudo modprobe -r acer-wmi
    sudo rfkill unblock all

If so, blacklist it:

    sudo su
    echo "blacklist acer-wmi" >> /etc/modprobe.d/blacklist.conf
    exit


mDNS or Multicast DNS service

It is provided by Avahi/Bonjour daemon, which lets small network computers to use names even if no central DNS is present. It uses by default the .local domain.

If you are not using .local for your DNS server then set DNS after mDNS in  nsswitch.conf (default)

hosts: files mdns4_minimal dns [NOTFOUND=return] mdns4

Otherwise .local is used by your DNS server (no use for mdns service)

hosts: files dns [NOTFOUND=return] mdns4_minimal mdns4

What is the difference between mdns4_minimal and mdns4?

To answer you, it is better to let know how to I collect such info and learn by yourself :) (## is for comment to tell objective for the command below it)

## Update "locate" database
~$ sudo updatedb
## Search for file with "mdns4_minimal" in its name
~$ locate mdns4_minimal
/lib/x86_64-linux-gnu/libnss_mdns4_minimal.so.2

## Look for which package installs that file
~$ dpkg -S /lib/x86_64-linux-gnu/libnss_mdns4_minimal.so.2
libnss-mdns:amd64: /lib/x86_64-linux-gnu/libnss_mdns4_minimal.so.2

## List all files from same package
~$ dpkg -L libnss-mdns:amd64
/.
/usr
/usr/share
/usr/share/lintian
/usr/share/lintian/overrides
/usr/share/lintian/overrides/libnss-mdns
/usr/share/doc
/usr/share/doc/libnss-mdns
/usr/share/doc/libnss-mdns/copyright
/usr/share/doc/libnss-mdns/README.html
/usr/share/doc/libnss-mdns/README.Debian
/usr/share/doc/libnss-mdns/style.css
/usr/share/doc/libnss-mdns/changelog.Debian.gz
/lib
/lib/x86_64-linux-gnu
/lib/x86_64-linux-gnu/libnss_mdns4.so.2
/lib/x86_64-linux-gnu/libnss_mdns_minimal.so.2
/lib/x86_64-linux-gnu/libnss_mdns.so.2
/lib/x86_64-linux-gnu/libnss_mdns4_minimal.so.2
/lib/x86_64-linux-gnu/libnss_mdns6.so.2
/lib/x86_64-linux-gnu/libnss_mdns6_minimal.so.2

## "README.html" looks the only documentation there, we open it
~$ xdg-open /usr/share/doc/libnss-mdns/README.html

  Documentation

  After compiling and installing nss-mdns you'll find six new NSS
  modules in /lib:

  libnss_mdns.so.2
  libnss_mdns4.so.2
  libnss_mdns6.so.2
  libnss_mdns_minimal.so.2
  libnss_mdns4_minimal.so.2
  libnss_mdns6_minimal.so.2

  libnss_mdns.so.2 resolves both IPv6 and IPv4 addresses,
  libnss_mdns4.so.2 only IPv4 addresses and libnss_mdns6.so.2 only
  IPv6 addresses. Due to the fact that most mDNS responders only
  register local IPv4 addresses via mDNS, most people will want to use
  libnss_mdns4.so.2 exclusively. Using libnss_mdns.so.2 or
  libnss_mdns6.so.2 in such a situation causes long timeouts when
  resolving hosts since most modern Unix/Linux applications check for
  IPv6 addresses first, followed by a lookup for IPv4.

  libnss_mdns{4,6,}_minimal.so (new in version 0.8) is mostly
  identical to the versions without _minimal. However, they differ in
  one way. The minimal versions will always deny to resolve host names
  that don't end in .local or addresses that aren't in the range
  169.254.x.x (the range used by
  IPV4LL/APIPA/RFC3927.)
  Combining the _minimal and the normal NSS modules allows us to make
  mDNS authoritative for Zeroconf host names and addresses (and thus
  creating no extra burden on DNS servers with always failing requests)
  and use it as fallback for everything else.

IPv6 Support

files & dns NSS modules, both supports resolving IPv6 besides IPv4.
However, mdns4 & mdns4_minimal are only for IPv4.

Same for mdns6 & mdns6_minimal are only for IPv6.

mdns & mdns_minimal support both IPv4 & IPv6, but its use should be avoided if only a single IP version is deployed in the network. Because It will try to resolve to IPv6 then fall-back to IPv4, which can create additional delay.

BTW, the current default setup of Avahi is IPv4, it is a decentralized service. So to go with IPv6, alls machine should reconfigured to use IPv6 in nsswitch and avahi too.

Are there any other []'s similar to [NOTFOUND=return]?

Yes, as we can see from man nsswitch.conf

   An action may also be specified following a service specification.   The  action  modifies
   the  behavior  following  a  result obtained from the preceding data source.  Action items
   take the general form:

       [STATUS=ACTION]
       [!STATUS=ACTION]

   where

       STATUS => success | notfound | unavail | tryagain
       ACTION => return | continue

   The ! negates the test, matching all possible results except the one specified.  The  case
   of the keywords is not significant.

   The  STATUS  value is matched against the result of the lookup function called by the pre‐
   ceding service specification, and can be one of:

       success     No error occurred and the requested entry is returned.  The default action
                   for this condition is "return".

       notfound    The  lookup succeeded, but the requested entry was not found.  The default
                   action for this condition is "continue".

       unavail     The service is permanently unavailable.  This can  mean  either  that  the
                   required file cannot be read, or, for network services, that the server is
                   not available or does not allow queries.  The default action for this con‐
                   dition is "continue".

       tryagain    The  service is temporarily unavailable.  This could mean a file is locked
                   or a server currently cannot accept more connections.  The default  action
                   for this condition is "continue".

   The ACTION value can be one of:

       return      Return  a result now.  Do not call any further lookup functions.  However,
                   for compatibility reasons, if this is the selected action  for  the  group
                   database and the notfound status, and the configuration file does not con‐
                   tain the initgroups line, the next lookup function is always called, with‐
                   out affecting the search result.

       continue    Call the next lookup function.

Related Questions:

Why does the host command not resolve entries in /etc/hosts?


you have many tools to do this.
you can use Teamviewer , FreeNX,VNC.

Installation of FreeNX:

Open your terminal and paste these lines one by one.

sudo apt-add-repository ppa:freenx-team
sudo apt-get update
sudo apt-get install freenx
wget https://bugs.launchpad.net/freenx-server/+bug/576359/+attachment/1378450/+files/nxsetup.tar.gz
tar -xvf nxsetup.tar.gz
sudo cp nxsetup /usr/lib/nx/nxsetup
sudo /usr/lib/nx/nxsetup --install

To Install TeamViewer
open your terminal and type this

wget http://www.teamviewer.com/download/teamviewer_linux.deb
sudo dpkg -i teamviewer_linux.deb

For More Information:
 FreeNX , VNC


Extremely slow login after upgrade from 11.10 to 12.04

I had a similar issue where logging in would show just the wallpaper for about 40 seconds before showing anything else, but subsequent logins were fast until the next reboot. I also had the same behaviour where logging in to a terminal first would make the graphical login fast, so it was a once-per-boot thing.

I changed a few things in trying to solve it but the probable culprits were either disabling IPv6, or disabling the couchdb service. IPv6 is something I'm not going to be able to use any time in the near future, and couchdb is something I installed a while ago and really doesn't need to be running all the time. In any case, the time from entering my password to having a usable desktop is now a couple of seconds.

If science demanded it I could always go back and narrow down which one caused the slowdown, but I'd try the IPv6 thing first and then see if any optional services are starting (you could try using BootChart to log your startup and spot any nonessential processes that take a long time).


The mobile broadband (express card Sierra wireless aircard 890) is no longer able to connect 3G network, after installing new U 14.04 LTS,

I've found the answer, thank to Chandana.
Be quoted:

This happened due to bugs(or bug) in the ModemManager 0.6.0.0 which shipped with Ubuntu 12.10. You can remove this modem manager version and downgrade in to 0.5.2.

To check modem manager version :

  dpkg -s modemmanager

download 0.5.2 version : link 64 --- i386

Source: Unable to connect via Mobile Broadband - But its detected - 12.10
section: Chandana's answer.


How do I cite Ubuntu in an academic thesis?

Yes. I think one of the best ways to cite it would be:

  I used Canonical Ubuntu x.x to produce my _______. Some of the applications I used are ______. Ubuntu is a open-source Operating System using the Linux kernel and based on Debian.

The reasons for each bit:

  I used Canonical Ubuntu x.x to produce my _______.

This is the main citation.

  Some of the applications I used are ________.

This are extra citations for the applications you used.

  Ubuntu is a open-source Operating System using the Linux kernel and based on Debian.

A short description of Ubuntu to tell the marker what Ubuntu is.


apt-get is telling you that you are using the latest version available for your version of Ubuntu.  That doesn't mean there aren't newer versions available in a newer (perhaps unstable) version of Ubuntu.

You have a few options:

Upgrade to a newer version of Ubuntu, that includes gedit 2.91.0 and libpeas 0.7.4
See if the Ubuntu Backports archive has gedit 2.9.10 and libpeas 0.7.4 built for your version of Ubuntu
Compile and install the newer versions of gedit and libpeas from the newer version of Ubuntu, leaving everything else alone.  This option often leads to more unmet build dependencies, which can turn into a complicated mess.  This is why Backports is so nice--it means someone else has already done that work for you.
Find someone who has built vtg-plugin for your version of Ubuntu (so it works with the versions of gedit and lipeas you already have)
Find an older version of vtg-plugin that doesn't require the newer dependencies.


Alright, this is going to get a little technical.  Plus you're going to need a spare partition or disk.

To start with, backup all your data on both systems.  Accidents happen easily.  Clonezilla is good for making copies of everything such that you can put it all back if you wipe out your disk.

So, find a USB drive, or disk partition with enough space to hold your wubi install.  Then follow the manual instructions at http://ubuntuforums.org/showthread.php?t=1519354 to move your wubi install to that space.  Read carefully and make sure you understand how it all works before trying it.

Once you have your install migrated into the clear, the simplest thing to do is to fire up Clonezilla ( http://clonezilla.org ) and make an image of it.  You want just the Ubuntu install, not the Windows install too.  Then fire up Virtual Box with Clonezilla.  Put the image in a Windows shared folder and configure Virtual Box's network settings so that you can access it.  You should then be able to tell Clonezilla to connect to the share, and restore the image to the virtual machine.

Personally I've only ever done it this way once.  It's a pain, and not worth it.

Easier way:  Do a clean install into Virtual Box, then fire up your wubi install.  Log out of the graphical shell and hit ctrl+alt+F1 to get a terminal prompt.  Log in to the terminal and cd to /home.  make a tarball of the user home folders with tar, and save it to your windows system, which will be mounted under /host.  (There are plenty of good sets of instructions on using tar elsewhere, so I'll just say tar --help for the rundown on the options)

I usually do the same thing with the contents of /var/cache/apt to save redownloading updates to the new system.

Then, go back to Windows, fire up Virtual Box, put the tarballs in a shared folder where you can get to them from the VM, and expand the tarballs back out into the directories from whence they came.  That will get all your personal settings and the packages for all the programs you had installed, so you have essentially the same install, only with fewer reboots and much less chance of accidentally nuking your disk.


How do I connect to an L2TP IPSec VPN using a PSK on 15.04?

Install the old client: https://launchpad.net/l2tp-ipsec-vpn

First install required packages:

sudo apt-get install gksu libgksu2-0 libctemplate2 libengine-pkcs11-openssl libp11-2 xl2tpd

Next download the old binaries and install with dpkg:

wget http://mirrors.kernel.org/ubuntu/pool/universe/o/openswan/openswan_2.6.38-1_amd64.deb

sudo dpkg -i openswan_2.6.38-1_amd64.deb

wget http://mirrors.kernel.org/ubuntu/pool/universe/l/l2tp-ipsec-vpn/l2tp-ipsec-vpn_1.0.9-1_amd64.deb

wget http://mirrors.kernel.org/ubuntu/pool/universe/l/l2tp-ipsec-vpn-daemon/l2tp-ipsec-vpn-daemon_0.9.9-1_amd64.deb

sudo dpkg -i l2tp-ipsec-vpn_1.0.9-1_amd64.deb
sudo dpkg -i l2tp-ipsec-vpn-daemon_0.9.9-1_amd64.deb

Open the client. Add a connection and configure as needed. Once you try to connect it may take awhile but be patient.


Way(s) of browsing the filesystem that are more flexible

You can use xdg-open to open files and directories from the command line. I have an alias of xopen to make the typing a little easier. Put this in your ~/.bashrc to do that, and to have a root file browser using sudo:

alias xopen="xdg-open"
alias xopen-root="sudo xdg-open"

It will open the file in the application that would be used if you double-clicked on it. For example, if you named a text file, it would open in gedit. And if you pass it a directory, it will open the file browser. So if I am in my home directory I can do

$ xopen Documents
$ xopen .

and the file browser (nautilus for me) will open that directory. Also note that xdg-open will return immediately - the new program is launched as it's own process and you can type in your next command.

To open a terminal from the nautilus file browser, you should install the nautilus-open-terminal package. Then you can right click on a folder, or in the blank space below the files, and open a terminal with the path set to that directory. Not sure how to make it a root terminal though - I always just use sudo myself.


Try to install the latest version (1.0.2) from Springseed website.


Cant connect an ESXI host behind an ubuntu NATusing Vsphere

For those who were wondering, I managed to find a solution while typing the question. I just checked if there were other ports to forward aswell and bingo.

https://kb.vmware.com/selfservice/microsites/search.do?language=en_US&cmd=displayKC&externalId=1012382#ESXi5x

ESXi 5.x    427 UDP VI / vSphere Client ESXi/ESX Host   CIM Service Location Protocol (SLP)
ESXi 5.x    443 TCP VI / vSphere Client ESXi/ESX Host   VI / vSphere Client to ESXi/ESX Host management connection

I forgot to portforward them. Now I can connect to it easily.


Setting root session and user session to same bus?

If you are writing a script which requires running as root, and needs to be accessed via DBus by users some how, you should be exposing the API via the System bus, not the Session bus.

As an example, see how the NetworkManager system service works.

For further documentation on how permissions work in DBus, see http://www.freedesktop.org/wiki/Software/dbus


Apt package update is failing for Ubuntu 18.04 LTS

You have wrong timezone set, fix this or use this workaround below:

Workaround

Add this to the command to apt-get commands:

-o Acquire::Check-Valid-Until=false

For example:

sudo apt-get -o Acquire::Check-Valid-Until=false update

Credits goes to here.

Edit:

If the workaround above did not work, then change your repository:

Go to Settings->Softwares & Updates and set Download from field to Main Server.

The cause of why it has happened maybe something is wrong with Indian Repository.


rsync filled up dev/nvme0n1p2: how do I reverse this?

But, the -v rsync option stands for "verbose"! It told you what it was doing.

Did you really run the rsync command with the

-n, --dry-run         perform a trial run with no changes made

option? I assume not.

The "*" character is special in the Linux shell, often standing for "All Files", so, to avoid unintended expansion, single quote ("'") all file patterns containing "*", e.g,

--exclude='/dev/*' --exclude='/proc/*' --exclude='/sys/*'

as shown in man rsync.

To illustrate this, replace sudo in your command with echo to see the expansions.

The space character ("") is also special. It is used to separate parameters, and MUST be quoted whenever it is part of a filename. There are 3 ways of quoting spaces, so your destination should by typed as:

/media/alastair/Seagate\ Basic
"/media/alastair/Seagate Basic"
'/media/alastair/Seagate Basic'

The actual rsync command (not the one with --dry-run) looks like you're trying to write into /media/alastair/Seagate, and, since /media is a directory on the root filesystem, you filled up '/'.

Look at it with

du -sk /media/alastair/Seagate
ls -l /media/alastair/Seagate

and free the space (if you're SURE) by

sudo rm -rf /media/alastair/Seagate


Remote Desktop Connection from Window 10 to Linux (Ubuntu 18)

xpra should work fine out of the box as long as you use the official packages from xpra.org, the ones from the Ubuntu repositories are just too buggy.


Unable to boot windows 8 after ubuntu 12.04 installation

You've got a mess. Strange things about your installation, some of which could be causing problems, include:

A computer that shipped with Windows 8 should boot in EFI mode and use the GUID Partition Table (GPT), but your disk is clearly using the older Master Boot Record (MBR) partitions. This suggests that you converted from GPT to MBR, which would render Windows unbootable.
Your MBR partition table clearly shows that your Windows installation uses the Windows Logical Disk Manager (LDM) configuration, aka "dynamic disks." This is Microsoft's equivalent to the Linux Logical Volume Manager (LVM), but the two technologies are different in detail and therefore incompatible. If you converted from standard partitions to LDM before installing Linux, then resizing operations by the Linux partitioner could have done serious damage to the LDM setup, making Windows quite unhappy.
As a sub-point of the former, I'm not at all sure that it's advisable to mix LDM partitions with conventional partitions on a single disk.

The easiest solution at this point is probably to wipe the partition table and re-install everything from scratch. This may be considerably less easy if you lack Windows installation media, though, or if you've got personal data in the Windows setup that you want to rescue. If either of those is the case, you might want to post a question to a Windows forum about recovery prior to repairing the setup.

Sorry I can't offer a simple and easy solution. If there is such a solution, I don't know what it is. I can think of a number of ways to proceed short of wiping your partition table, but they're all risky. For instance, you could use a Windows tool like EaseUS Partition Manager to try to convert back from LDM to conventional partitions, then either convert from MBR to GPT (if I'm right that Windows originally booted in EFI mode) or try to get Windows booting from a non-LDM MBR setup.

In the future, do not use Windows partitioning tools to prepare a disk for use with Linux. (That's one common way to dig yourself into an LDM hole.)


How to run Display Settings from the CLI virtual terminal?

You must be referring to:

gnome-control-center display

You can find the command in the .desktop file:

gnome-display-panel.desktop

This .desktop file is to be found in /usr/share/applications


I have the ASUS FZ50VW-NS51 and I was able to get ubuntu to load using

i915.preliminary_hw_support=1 nouveau.modeset=0 acpi_osi=! acpi_backlight=vendor idle=nomwait

as kernel parameters (Press e at the grub menu after selecting the boot option you want).

Edit: Any time you reboot before installing the latest nvidia drivers you will have to specify the same parameters in order to boot.


Videos only play when the window is resized to the smallest setting

There's a few things you can do to optimize your system that might solve this bizarre issue.

First, check that you have correct drivers for your GPU, if you even have one.  If you're just running integrated graphics, move on to the next step...

If your system is legacy you can try running a more lightweight desktop environment.  Unity is not a good GUI for old hardware.  I suggest the lubuntu, xubuntu, or kubuntu desktops.

sudo apt-get remove --purge ubuntu-desktop

This will uninstall unity and x. --purge line will remove the old files, to avoid conflict and optimize hard disk usage.  Next, pick which desktop environment to replace it with.

xubuntu - This is probably what you should try first.  Another lightweight Gnome desktop, but with significantly more features than lubuntu.  Works well on old hardware.

sudo apt-get install xubuntu-desktop

lubuntu - Extremely lightweight desktop environment running Gnome.  Works best on PC's with less than 1gb of ram.

sudo apt-get install lubuntu-desktop

kubuntu - This is an alternate suggestion because it's a very unique flavor of Ubuntu.  This desktop environment is based off of the Plasma GUI, a powerful feature rich GUI thats light on appearance and similar to Windows in style.

sudo apt-get install kubuntu-desktop

Kubuntu desktop environment really shines when you use the Koffice office suite with it.  Features like drag and drop to bring spreadsheets and graphs and images into word documents that are unavailable on any other desktop environment make it very unique.  Koffice is slightly less compatible with MSOffice formats than libre office though.

Hope this helps.  I can't think of anything else to help you, your problem definitely sounds like a lack of VRAM is causing it.  Also, XBMC runs pretty choppy even on my computer, and I have a next gen system, so you should avoid that software if possible.


Is the second monitor disabled? Please check in the status bar to make sure it is enabled.


This model should be fully compatible without issue
Certified For Ubuntu


How do I change the shortcuts in mplayer?

Assuming you are talking of mplayer itself, according to the man page1:

  MPlayer has a fully configurable, command-driven control layer which allows you to control MPlayer using keyboard, mouse, joystick or remote control (with LIRC).  See the -input option for ways to customize it.

  ...

 -input <commands>
          This option can be used to configure certain parts of the input system.  Paths are relative to ~/.mplayer/. Available commands are:
...
             conf=<filename>
                  Specify input configuration file other than the default ~/.mplayer/input.conf.  ~/.mplayer/<filename> is assumed if no full path is given.
             keylist
                  Prints all keys that can be bound to commands.
             cmdlist
                  Prints all commands that can be bound to keys.

Edit ~/.mplayer/input.conf and add the following line (using the examples from the mplayer website):

RIGHT pt_step 1

1 I am not linking to the Ubuntu manpage because it differs from what I actually have on my system. In particular, for me, mplayer options began with a single hyphen and not double hyphens.


First you just make your USB using USB Universal Installer and you are given an option to "Make the Drive Persistent", Check Box, yes, and make the disk.

Second, load up the instance, and for remapping keys you need two tools, xev  and xmodmap.

Start terminal and run xev.

If the key you are mapping has a different meaning when used with the Shift key (for example for British keyboard layouts, Shift+2 gives quotation marks) then you can simply list the secondary command after the first. For example if you want the key with code 53 to map to backslash normally, but to the bar symbol when used with shift, you might do:

xmodmap -e "keycode 53 = backslash bar"

xmodmap -pke >~/.Xmodmap

(it creates a file named .Xmodmap in your home directory (~))

Then you have to create a file named .xinitrc in your home directory where you put command xmodmap .Xmodmap in.

You can now modify .Xmodmap and run xmodmap .Xmodmap from console to see the changes.

source: Ubuntu Foruns


What apps to sync movie subtitles easily are available for Ubuntu?

I'm surprised no one mentioned this:
gnome-subtitles
It has impressive features, it's extremely easy to use and very well-polished. A lot of care and detail in its UI (check the char count in each line).
I use it all the time to shift subtitle timings to/from HDTV to BDRip/DVDRip releases.

Side-note: VLC player has on-the-fly subtitle timing shift. It will not change your .srt file, only the playback, but it's very convenient for movies you'll only watch once and don't care about saving the adjustments. I assign them to UP and DOWN directional keys.


I've tried a different approach. I've installed Lubuntu on the machine and it is working without any problems. Probably since it is an old machine it struggles with the more heavy distributions. I also purchased a new NUC, 10th generation and have managed to install Pop!_OS 20.04 without any problem.
Now I have two NUCs with different distributions, the old one I will try to use for long operations that require some time (e.g. uploading data to a backup server) and the new one as my daily use machine.


How to make active application float to the top of the launcher

Introduction
The script bellow makes the icon of currently active window float to the top of the launcher.  It can be ran manually or as part of startup applications to start with the user session.
Setup
User can copy  the script source from here, or obtain copy of the script through git:

sudo apt-get install git
cd /opt ; sudo git clone https://github.com/SergKolo/sergrep.git
sudo chmod -R +x sergrep

The script file is /opt/sergrep/float_active_app.sh
To make the script start automatically on every login, refer to
How do I start applications automatically on login? . Provide /opt/sergrep/float_active_app.sh (full path) as the command
Source

#!/usr/bin/env bash
#
###########################################################
# Author: Serg Kolo , contact: 1047481448@qq.com
# Date: April 9 , 2016
# Purpose: Make the icon of currently active app float to
#          the top of unity launcher
# Written for:
# Tested on: Ubuntu 14.04 LTS
###########################################################
# Copyright: Serg Kolo , 2016
#
#     Permission to use, copy, modify, and distribute this software is hereby granted
#     without fee, provided that  the copyright notice above and this permission statement
#     appear in all copies.
#
#     THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
#     IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
#     FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
#     THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
#     LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
#     FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
#     DEALINGS IN THE SOFTWARE.

ARGV0="$0"
ARGC=$#
get_active_app()
{
  qdbus org.ayatana.bamf /org/ayatana/bamf/matcher \
      org.ayatana.bamf.matcher.ActiveApplication
}

get_active_desktop_file()
{
  active_app=$(get_active_app)
  if [ -n "$active_app"  ];then
     qdbus org.ayatana.bamf "$active_app" \
        org.ayatana.bamf.application.DesktopFile | \
        awk -F '/' '{print "application://"$NF}'
  fi
}

get_launcher_items()
{
  gsettings get com.canonical.Unity.Launcher favorites | \
     awk '{ gsub(/,|\[|\]/,""); print}'
}

make_new_list()
{

 array=( $( get_launcher_items ) )
 printf "%s, " "$active"
 COUNT=0
 for item in ${array[@]} ; do
   COUNT=$(($COUNT+1))

   if [ "$item" = "$active"   ];then
     continue
   fi

   if [ $COUNT -eq ${#array[@]}  ];then
      printf "%s " "$item"
   else
      printf "%s, " "$item"
   fi
 done
}

set_launcher_items()
{
  gsettings set com.canonical.Unity.Launcher favorites "$1"
}

main()
{
  local active=""
  while true;
  do
    active="'$(get_active_desktop_file)'"
    if [ "$active" = "'application://compiz.desktop'" ] || [ -z "$active"   ] ;then
       continue
    fi
    new_list="[$(make_new_list)]"
    set_launcher_items "$new_list"
  sleep 0.25
  done
}

main


For Windows 64-bit guest and if you want to use more than 1 CPU in your guest we need to enable I/O APIC prior to installing Windows.

  Enabling the I/O APIC is required  for 64-bit guest operating systems, especially Windows Vista; it is also required if you want to use more than one virtual CPU in a virtual machine.

Reference: Virtual Box User Manual

This can be done in the System -> Motherboard setting in the VirtualBox Manager.

Note: These setting has to be made before installing Windows as only then Windows will be installed with the appropriate kernel.


Unable to delete file whose name starts with "sed"

There is a small lock in the right upper corner of this file. This means that the current user does not have permissions to delete/modify the file.

You can delete this file with sudo:

open a terminal and type:

sudo rm /home/bbudd/Desktop/sedxzNQQm


how can I make a portable ubuntu installation on a usb stick secure bootable?

this command solved my problem now:

grub-install --efi-directory /mnt/esp --boot-directory /mnt/rootfs/boot --target x86_64-efi --removable /dev/sdb --uefi-secure-boot

this finally lets me boot on uefi systems with secure boot enabled.
the only errors I get while booting is

error: file ´/boot/' not found.
error: no such device: /.disk/info.

it´s no real problem as it still boots, but if you have an idea what causes it and how to solve, I´d be thankful for any hint.
    error: no such device: /.disk/mini-info.


DEB file not installing, wrong architecture?

The wrong architecture refers to the type of processor your device is using.

You have downloaded a deb file designed for a processor running the amd64 machine language, commonly referred to as a 64bit processor or an x86_64 processor.

But either the processor you are using is not a 64 bit processor, or you have installed a version of Ubuntu not designed for 64 bit.

How old is this computer? If it is more then 5 years old, it may be a 32 bit processor, in which case you need the i386 package (or i486 or i686 or x86, depending on site notation, for most purposes, it's the same thing).

Is it a micro-device, like a beaglebone? It may be using an ARMv7 architecture.

Is it a chinese system, like a Lemote Yeelong? It may be using a MIPS architecture.

If you are certain it is an x86_64 processor, check to make sure you haven't installed the 32 bit version of Ubuntu.


You Can Use Jupiter

  Jupiter is an applet which allows you to switch between maximum and high performance and power saving mode, change the resolution and orientation, enable or disable the bluetooth, touchpad, WiFi and so on.

You can install by adding the ppa ppa:webupd8team/jupiter and installing jupiter from the software center.


make file error, trying to install intel power gadget

I got the same problem and managed to solve it by simply change the -lm flag to the end off the GCC command.

So the Makefile now looks like this:

CFLAGS=-g

all: rapl_lib_shared rapl_lib_static power_gadget_static

rapl_lib_shared:
gcc $(CFLAGS) -fpic -c msr.c cpuid.c rapl.c
gcc $(CFLAGS) -shared -o librapl.so msr.o cpuid.o rapl.o

rapl_lib_static:
gcc $(CFLAGS) -c msr.c cpuid.c rapl.c
ar rcs librapl.a msr.o cpuid.o rapl.o

power_gadget_static:
gcc $(CFLAGS) power_gadget.c -I. -L. -o power_gadget ./librapl.a -lm

power_gadget:
gcc $(CFLAGS) power_gadget.c -I. -L. -lrapl -o power_gadget -lm

gprof: CFLAGS = -pg
gprof: all
./power_gadget -e 100 -d 60 >/dev/null 2>&1
gprof power_gadget > power_gadget.gprof
rm -f gmon.out
make clean

clean:
rm -f power_gadget librapl.so librapl.a msr.o cpuid.o rapl.o


Apparently, I also needed to download and extract the AX200 wifi drivers from Intel and move them into /lib/firmware


Gparted can not manage LVM. What are you trying to do ?

See https://wiki.ubuntu.com/Lvm and/or update your question.


What is this line at the top of many files?

It's not just /usr/bin/env python but #!/usr/bin/env python and this line is called a shebang.

I'm quoting Wikipedia:

  Under Unix-like operating systems, when a script with a shebang is run
  as a program, the program loader parses the rest of the script's
  initial line as an interpreter directive; the specified interpreter
  program is run instead, passing to it as an argument the path that was
  initially used when attempting to run the script.[8] For example, if a
  script is named with the path "path/to/script", and it starts with the
  following line:

#!/bin/sh

  then the program loader is instructed to run the program "/bin/sh"
  instead (usually this is the Bourne shell or a compatible shell),
  passing "path/to/script" as the first argument.

  The shebang line is usually ignored by the interpreter because the "#"
  character is a comment marker in many scripting languages; some
  language interpreters that do not use the hash mark to begin comments
  (such as Scheme) still may ignore the shebang line in recognition of
  its purpose.

In my case (13.10 Desktop), /usr/bin/env python will default to python2.7 but it could be python3.4 depending on your system defaults (e.g. 14.04 Server).

$ /usr/bin/env python
Python 2.7.5+ (default, Feb 27 2014, 19:37:08)
[GCC 4.8.1] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>>


How to install theme without using user-theme extension?

Yes you can.

Extract your theme to ~/themes or /usr/share/themes

I use this command for manually change theme and icon on ubuntu.

Open terminal Ctrl+Alt+T and run following command:

Icon Pack

gsettings set org.gnome.desktop.interface icon-theme 'theme'

Theme

gsettings set org.gnome.desktop.interface gtk-theme 'theme'

gsettings set org.gnome.desktop.wm.preferences 'theme'

gconftool-2 --set --type string /apps/metacity/general/theme 'theme'

Change 'theme' with your theme name


How to execute a script when application is terminated

First of all, it's generally considered a bad practice to edit files in /usr/share/applications. In addition, it's highly inefficient, because it comes as part of a package, and if there's update to that package, guess what ? Your changes will be overwritten. If you absolutely, 100%, need to make changes, make a custom .desktop file and store it in ~/.local/share/applications

Instead, I would recommend using a script that uses while loops and pgrep -f to wait for the app you want. For example, in the example below , the script uses firefox as process string.

#!/bin/bash

process_string="firefox"
while true
do

    while ! pgrep -f "$process_string"
    do
       echo "Waiting for $process_string"
       sleep 3
    done

    while pgrep -f "$process_string"
    do
       echo "Waiting for $process_string to exit"
       sleep 3
    done

    # place the command you want to occur when
    # process exits here
sleep 3
done

The script runs in continuous loop so you could add it as part of Startup Applications to launch upon logging in


Yes. It's a setting.

Apt already does background apt updates and apt upgrades...

/lib/systemd/system/apt-daily.timer           // update
/lib/systemd/system/apt-daily-upgrade.timer   // upgrade

...all you really need to do is stay out of it's way, and to tweak the settings as shown below.

Edit the config file /etc/apt/apt.conf.d/50unattended-upgrades:

Example command: $ sudo nano /etc/apt/apt.conf.d/50unattended-upgrades

Step 1: Edit your sources. The default settings include only the -security repo. You can update this to include all your sources. Best practice is to add stable, reliable sources like -updates and -security (those two should be the great majority of your upgrades!) This is NOT recommended for -proposed or other testing/unstable sources.

// Automatically upgrade packages from these (origin:archive) pairs
//
// Note that in Ubuntu security updates may pull in new dependencies
// from non-security sources (e.g. chromium). By allowing the release
// pocket these get automatically pulled in.
Unattended-Upgrade::Allowed-Origins {
        "${distro_id}:${distro_codename}";
        "${distro_id}:${distro_codename}-security";
        // Extended Security Maintenance; does not necessarily exist for
        // every release and this system may not have it installed, but if
        // available, the policy for updates is such that unattended-upgrades
        // should also install from here by default.
        "${distro_id}ESM:${distro_codename}";
        "${distro_id}:${distro_codename}-updates";
//      "${distro_id}:${distro_codename}-proposed";
//      "${distro_id}:${distro_codename}-backports";
};

Step 2: Enable Autoremove. Simply uncomment the final line:

// Do automatic removal of unused packages after the upgrade
// (equivalent to apt-get autoremove)
//Unattended-Upgrade::Remove-Unused-Dependencies "true";

Step 3: Do upgrades at shutdown instead of in the background. Simply uncomment the final line:

// Install all unattended-upgrades when the machine is shutting down
// instead of doing it in the background while the machine is running
// This will (obviously) make shutdown slower
//Unattended-Upgrade::InstallOnShutdown "true";


If you use ddrescue command from gddrescue package (it's not clear), then to speed up the process (and ensure your drive doesn't die too quickly!) you can use a log file:

sudo ddrescue /dev/sdb2 /mnt/sda4/backup.img logfile

After a couple of ours (or a day) of copying, you can stop ddrescue, let your drive rest (or put it in a colder room or storage), and when it's cooled down you can resume the process where it left off using the same command as above. Since the hard-drive will have time to breath, it will improve operational performance and might speed up the process. It is recommended to do that if the drive is dying.


How do I set the hotkey Print to Rectangular Region in Spectacle?

I'm assuming you're on Kubuntu 18.04. This answer is based on Kubuntu 18.04.

Open System Settings > Shortcuts > Custom Shortcuts.

In there, click on the arrow-head, circled in red, to the left of Screenshots to see the available default actions.

You'll see that Print starts the screenshot tool

and that Meta+Shift+Print takes a screenshot of a rectangular area

Now, to use Print to take a rectangular screenshot area, you first need to free up the Print key.

To do so,

go back to Start Screenshot Tool
click on the Trigger tab
click within the the box next to Shortcut
then simultaneously press Control+Shift+PrintScreen
click Apply in the lower right corner of the window.

Next, re-assign the trigger for Take Rectangular Region Screenshot the same way but just press the PrintScreen key and click Apply.

Now, whenever you press the PrintScreen key, you'll be prompted to select a rectangular area.


Ubuntu 12.04 on Dell Latitude E6530 i5/HD4000/FHD

Your machine will work perfectly fine right out of the box with Ubuntu!

For Intel graphics you don't have to install anything, all is in kernel. Just make sure you install a recent Ubuntu release (12.04.3+ or 13.04+).

Fan control is done fully by an embedded controller as far as I can see with nothing to tweak. But it's really really silent in idle. I'm getting 11W idle power usage (with screen on) and 7W with screen off. That's about as low as you will get with this platform.

I've got a E6530 with Nvidia+Intel in Optimus, but I have the Nvidia card disabled (because I'm not using any graphic applications).


No options of ubuntu and windows 10 in grub menu when I dual booted

Remove the USB drive and boot, then see if Windows and Ubuntu show in the menu


Explicitly accept change for PPA 'Label'

It would help if you posted your repositories, but, with that said, you sort of have 2 ways to fix this.
First would be to use apt rather than apt-get. apt is preferred over apt-get for interactive use in recent Ubuntu versions; and apt should, in theory, fix this for you.
sudo apt update
sudo apt upgrade

Your second option is to use --allow-releaseinfo-change
sudo apt-get update --allow-releaseinfo-change

If those options do not resolve the issue, please post your repositories, are you using mixed repositories or pinning, and, finally, tell us, is this an upgrade ?


Is it possible to hybrid boot(fast startup) ubuntu like windows 10?

There is no comparable feature to Windows Fast Startup available in Ubuntu.

By 'comparable feature', I mean hibernate that is (deliberately) used in place of poweroff in order to speed the poweron/boot experience for users. Many (not all) users can enable Hibernate on their Ubuntu system, which will achieve most of the same effects as Fast Startup...but the OP has already rejected hibernate in the Question as a useful solution.

Ubuntu developers work very hard to minimize startup time while keeping the boot cycle simple enough for the community to support. All kinds of techniques are used (ureadahead, compressed kernels, systemd targets, etc.) to minimize the amount of (slow) IO activity, and get you to login as fast as possible.

And it works: Boot tends to be much faster than it was 10 years ago.

Users who need help diagnosing problems or delays with their particular system's boot are welcome to open a new question.

Community volunteers are welcome to help test boot improvements in the next pre-release version of Ubuntu.

Developers who have a new, supportable technique to improve boot are welcome to bring it to the dev channels. Ubuntu developers are happy to listen to new ideas.


Navigating in the Nautilus 3.10.1 side pane using the keyboard

You can toggle between navigating the side pane and the main window (using the arrow keys) by pressing the F6 key. So,

F6 and then any  arrow keys : Navigate main window.

F6 and then  up/down : Navigate side pane.


How to get back the /var/lib/dkpg folder?

Run these:

sudo mkdir /var/lib/dpkg
sudo cp /var/backups/dpkg.status.0 /var/lib/dpkg/status
sudo sh -c "echo >> /var/lib/dpkg/lock"
sudo sh -c "echo >> /var/lib/dpkg/available"
sudo mkdir /var/lib/dpkg/alternatives
sudo mkdir /var/lib/dpkg/info
sudo mkdir /var/lib/dpkg/parts
sudo mkdir /var/lib/dpkg/updates

This will hopefully restore the necessary files, albeit some package errors may occur from recent transactions, as the status will not be up to date.

You can then test apt-get for any errors:

sudo apt-get install sl

You may need to update the package cache first with sudo apt-get update

sl is a small program that basically just shows a steam train in the terminal for when you mistype ls, but I have included it here as it is small, and unlikely to be installed ;-)


As @falconer says, you can mount the device read-write to sudo chmod u+x file successfully. This may not be feasible if you don't have access rights or the file system driver doesn't support mounting it writeable.

You could also copy the file to a device which is already mounted read-write (/tmp comes to mind) and run it from there. Of course this might not work if the script somehow depends on which directory it's run from (which scripts generally should not).


Huawei MU736 3G modem not showing in network manager and not connecting

The problem is solved with later versions of Ubuntu, just remember to insert the SIM card and the modem will show up in the menu and will work fine.


18.04 headphone jack no sound after installing remotemouse

I had the same problem.

Here is the way that I found which may work for your system, as I have Ubuntu 18.04 with ubuntu-unity-desktop too.
Type in your cmd prompt:
    alsamixer
It will show you system sound control, where you can try to play, and adjust around. Try to turn on all the MM bars (which is muted) or switch to other sound cards if you have.

While you are adjusting them, go to Setting>>Sound>>Test Sound, try to test it if it works.

Good luck.


Yeti Nano flashes yellow in Ubuntu Studio 20.04

Yeti nano only deal with 48kHz.
You have to set your default setting as 48kHz and not 44.1kHz.
You can add this line :
default-sample-rate = 48000

in ~/.config/pulse/daemon.conf for local setting or in /etc/pulse/daemon.conf for global setting (needs to be root).
then restart pulseaudio with
$ pulseaudio -k

(see https://medium.com/@gamunu/enable-high-quality-audio-on-linux-6f16f3fe7e1f)
PS: to be more precise, since default alternate-sample-rate is 48kHz in pulse, it explains why it works when the source is already 48kHz (see https://manpages.debian.org/unstable/pulseaudio/pulse-daemon.conf.5.en.html)


You are using a mobile GPU, so i'm assuming you are using it in a laptop, probably in a configuration with a 3rd Gen Intel Core CPU (Ivy Bridge). All mobile versions for the Ivy Bridge feature the Intel HD 4000 graphics as integrated graphics processor (IGP).

Summary

Delete /etc/X11/xorg.conf (don't forget to make a backup)
Manually switch between IGP and dedicated GPU using either Bumblebee or PRIME.

Background

This configuration has the advantage, that for less graphic intensive applications the IGU can be used which has a lower energy-consumption. However, in my case it meant, that Ubuntu always used the IGU independent of whether I had installed the Nvidia drivers or not. That's why your configuration says This driver is activated but not currently in use.

Low Resolution Problem

You probably have never used your Nvidia card until you asked the question. The xorg.conf generated by nvidia-xconfig expects a Nvidia card to be used, that is not the case, so I guess the X-server uses some failsafe output mode. That Problem can easily be solved  by deleting xorg.conf file.

sudo rm /etc/X11/xorg.conf

Than restart your Window Manager (or reboot), e.g.

sudo restart lightdm

You should have your resolution back now.

Switching between IGU and dedicated GPU

There are multiple ways how to approach enabling support for hybrid graphics. The Hybrid Graphics Linux Team (new user max 2 links, google for launchpad+hybrid-graphics-linux) gives a comprehensive overview. From what I've seen the easiest to use and most advanced technologies are Bumblebee and PRIME. In both cases you start the applications that should use the dedicated GPU with a specific prefix.

Bumblebee

Bumblebee either uses the free noveau or the proprietary Nvidia driver. So far I only tried Bumblebee, which seems to be the better working solution for the Intel and Nvidia combination.
There is an Ubuntu wiki page (google wiki+ubuntu+Bumblebee), that describes the steps on how to install it. After the installation you can run applications using the dedicated GPU by prefixing them with optirun. E.g.:

optirun glxgears

The Nvidia settings will only work if the card is active so you have to run

optirun nvidia-settings -c :8

to get to the settings. The monitor configuration works via the default tool.

Addendum

PRIME seems to be working good in the combination AMD-IGU with Nvidia GPU. But There does not seem to be much comprehensive reading about it.

The hybrid support is still somewhat early and depending on your specific configuration either PRIME or Bumblebee may be the better solution for you.


How can I get my wifi to work on my Dell 3521 laptop?

some times ubuntu initially drivers will not work so,you need to update your drivers to work wifi in ubuntu , so initially connect pc/laptop with "cable" and it automatically detect your internet connection.

After that you can update the drivers then restart the pc , unplug the cable and now you can search your wifi and give password for connection.

Open "Additional Driver" option , it will search the drivers that are required for your PC and Card to support .

After that a list of driver being show , here you can select the driver according to you manufacturing company and Broadcom STA wireless Driver work fine with all cards.

You can find the package --->

sudo lspci
sudo dpkg --get-selections


Change remote desktop permissions from the command line (remotely?)

Provided you have setup your ssh server and client to accept X-forwarding we can start the Vino Preferences Manager by the following command:

ssh -X <remote>
user@remote:~$ vino-preferences

By this we can enable the vino server, and change settings including VNC password.


Instead of doing everything in one line and outputting to file, separate it in two parts - output the HEMES string and then append the n{1...1600} sequence: printf "%s" HEMES > file_a; printf "%s\t" n{1..1600} >> file_a.

If you specifically need to remove that tab between HEMES and n1 in an already existing file, here's an awk solution:

awk ' {sub(/[[:blank:]]/,""); print}  ' file_a > tmp_file && cat tmp_file > file_a.

What this does is take sub function, which deletes the first occurrence of the tab, we output that text to a temporary file, and then take those contents back to file_a. The reason for the switching between files is this: unless you are using awk version that allows inline editing (gnu awk, I believe), this will work in any case - awk, mawk, nawk, etc.


graphic problems with chicken invaders and epsxe

If you wish to run these specific programs reliably and with full access to all of their features, your best option is to return to Windows and try to resolve whatever problems you may have been having with it. Ubuntu is not intended to be a fully functional Windows emulator (nor is any other flavor of Linux), but rather it is a different system with its own programs, which can run some Windows applications quite well and others not at all. Even for those program that do work, it can be challenging for a novice to get started with Wine.


How to erase free space on a hard drive quickly and easily?

(Since you've specified that the laptop has a hard drive, I'll give instructions for that here, but in case you actually have an SSD, you'll want to follow the Memory Cell Clearing instructions on the Arch Wiki, which are a little more involved but work on Ubuntu and are much faster.)
As @guiverc suggested, DBAN is a good option here, but there's a more convenient way to use it, since you'll be reinstalling Ubuntu anyway. First, make a bootable Ubuntu USB stick like you normally would for an Ubuntu install. Boot into a live system from the USB stick (as Ubuntu can't erase your hard drive if it's running off it).
Open a terminal on the live system, and install nwipe (which is DBAN packaged for Linux):
$ sudo add-apt-repository universe
$ sudo apt install nwipe

Next, determine the device name of your hard drive. The easiest way to do this is by running the Disks tool included with Ubuntu. Select your hard drive, and it will show a device path like /dev/sda in the title bar. (Here's an example screenshot; you want the name without a number.) Once you have this path, run nwipe in your terminal (replacing /dev/sda with your drive's device path, if it's different):
$ sudo nwipe /dev/sda

nwipe has a number of different presets, the default being overwriting with three passes of random data and one of zeros. (You can choose more or fewer passes depending on how much time you have.) Press Shift+S to get it started, and then let it run — it can take 1–12 hours, depending on the size and speed of the drive. (A 1TB drive generally takes closer to 12 on the default setting.)
Once it's done, you'll need to reinstall Ubuntu. (If you're selling or giving away the laptop, you might find the OEM install mode useful.)


Which INPUT rules do I need to add to iptables so apt (apt-get, aptitude) can work (update, upgrade, search, install)?

When you send a HTTP request to the other server, you're using TCP. First, a SYN packet go outside to the other server from a random high port, then you'll receive a ACK response. Finally you send SYN/ACK to the server and the server responds with the requested document (in multiple packets). Your rules do not allow the ACK packet to be received and therefore the connection cannot be established. Add a rule like:

-A INPUT -m state --state RELATED,ESTABLISHED -j ACCEPT

You don't get iptables logs for free. Your rules should look like:

# if no rule matched, the input should be dropped
-P INPUT DROP

-A INPUT -p tcp --dport 80 -j ACCEPT
-A INPUT -p tcp --dport 443 -j ACCEPT
# etc

# the limit prevents your logs from being flooded if there are a lot packets being captured
-A INPUT -m limit --limit 5/min -j LOG --log-prefix "iptables denied" --log-level debug

Note that I've omitted iptables before the commands, I recommend using iptables-restore (or iptables-apply for testing) to avoid locking yourself out if a rule fails to apply. The file to be passed to the command looks like:

*FILTER
# your rules here, for example:
-P INPUT DROP
-P INPUT -m state --state ESTABLISHED,RELATED -j ACCEPT
COMMIT

A newline after the COMMIT line is mandatory.

By default, the entries go to /var/log/kern.log. Not good if you want to differentiate between kernel and iptables messages, so create a filter for rsyslog in /etc/rsyslog.d/iptables.conf containing:

:msg,contains,"iptables denied" /var/log/iptables.log
& ~

This will filter iptables errors and send those to /var/log/iptables.log.


Display problem after switching to GNOME3 from unity in Ubuntu 16.04

The problem is associated with gtk-theme you're using, not with display manager. That theme is incompatible. I suggest using other theme.

To switch to default Adwaita theme, which should work always in GNOME, use this command

gsettings set org.gnome.desktop.interface gtk-theme 'Adwaita'


Ubuntu 16.04.5 launcher spinning for Android9 usb-connected phone

After some time passed, the issue disappeared, which may be due to a combination of operating- system-update and whatever fixes came with ubuntu 16.04 .

The symptom disappeared after the manufacturer (in my case Sony) issued a software update to Android9, which I applied to the phone. However, many fixes had also arrived for Ubuntu so I cannot say which was decisive in fixing the issue.

A key detail is that the /var/log/syslog still shows the following (at current date), but Ubuntu 16.04 lets me open photographs on the Android9 device regardless of this error:

  Jan 28 12:36:23 host  mtp-probe: checking bus 3, device 7:
  "/sys/devices/pci0000:00/0000:00:14.0/usb3/3-2"

  Jan 28 12:36:23 host  mtp-probe: bus: 3, device: 7 was an MTP device

  Jan 28 12:36:23 host  org.gtk.vfs.Daemon[7066]: PTP: reading event an
  error 0x02ff occurredDevice 0 (VID=0fce and PID=01f1) is UNKNOWN in
  libmtp v1.1.10.

  Jan 28 12:36:23 host  org.gtk.vfs.Daemon[7066]: Please report this
  VID/PID and the device model to the libmtp development team

  Jan 28 12:36:23 host  gnome-session[7187]: (nautilus:30509):
  GLib-GIO-CRITICAL **: g_dbus_interface_skeleton_unexport: assertion
  'interface_->priv->connections != NULL' failed

  Jan 28 12:36:23 host  gnome-session[7187]: (nautilus:30509):
  GLib-GIO-CRITICAL **: g_dbus_interface_skeleton_unexport: assertion
  'interface_->priv->connections != NULL' failed

  Jan 28 12:36:23 host  gnome-session[7187]: (nautilus:30509):
  Gtk-CRITICAL **: gtk_icon_theme_get_for_screen: assertion
  'GDK_IS_SCREEN (screen)' failed

  Jan 28 12:36:23 host  gnome-session[7187]: (nautilus:30509):
  GLib-GObject-WARNING **: invalid (NULL) pointer instance

  Jan 28 12:36:23 host  gnome-session[7187]: (nautilus:30509):
  GLib-GObject-CRITICAL **: g_signal_connect_object: assertion
  'G_TYPE_CHECK_INSTANCE (instance)' failed

  Jan 28 12:36:23 host  org.gtk.vfs.Daemon[7066]: Android device
  detected, assigning default bug flags

In addition, I had reported to the lipmtp folks, the unknown VID/PID as suggested by the message above, and I was informed that the ID was in libmtp v1.1.14 (but my libmtp is still v1.1.10 in ubuntu 16.04), so there's more than one factor involved than the missing VID/PID.

In any case, check for updates to Android9 from the manufacturer, and check libmtp version.


Bluetooth not finding any devices on 12.10

Type Additional Drivers in dash. Open it. It will check for drivers automatically and suggest for installing driver if found any.


Cant launch TOR process? [warn] Could not bind to 127.0.0.1:54: Permission denied

Mar 29 12:08:04.059 [warn] Could not bind to 127.0.0.1:54: Permission denied
Port 54 is already being used by something. If you already have an old TOR process using the port, use sudo pkill tor to remove it. If not, some other process is using the port. You can check this using netstat or other commands to check port availability.


Can't connect local network VNC server when OpenVPN client is connected on this server

Option #1
Try sshing from B to A (in a terminal), and then using it as a tunnel to connect VNC.
Steps:

ssh -l <user name> -L 59000:localhost:5900 <server A>.
Or  ssh -L 59000:localhost:5900 <user name>@<server A>
Notes: <user name> is only needed if not the same in the server and client. 59000 and 5900 can be changed. <server A> can be named in ~/.ssh/config or used directly with ip.
VNC to localhost:5900.

Sources:

https://www.techrepublic.com/article/how-to-connect-to-vnc-using-ssh/
https://health.ucdavis.edu/irc/content/start/computing/vnc_ssh_tunnel.html

Option #2
Get the IP of server A in the network and VNC to that IP.
Related

https://superuser.com/questions/744022/cant-vnc-to-a-machine-connected-through-openvpn
https://forums.untangle.com/openvpn/12376-vnc-through-openvpn.html


How do I make a Live USB without destroying my Windows computer?

When you boot from the Live USB, you should be able to select Try Ubuntu. This option allows you to run Ubuntu from your USB, without installing it to your computer. If you want to save the changes you made to Ubuntu when you unplug the USB, you need to put Ubuntu on the USB again, but enable Persistance. Persistance allocates some space on the USB that allows you to save changes you make to the USB, such as installing packages or downloading files.


You need to boot from a LiveCD/USB.
Locate your original root partition using GParted. take note of it's name (e.g.: /dev/sda1).
Run these commands, replace $PARTITION with your partition (noted above)

sudo mkdir /mnt
sudo mount "$PARTITION" /mnt
sudo -H gedit /mnt/etc/default/grub

A text editor will open the GRUB configuration file. Correct any problems, e.g.: GRUB_DEFAULT, then save and close the window.
Run these commands in a terminal:

for i in sys proc run dev; do sudo mount --bind "/$i" "/mnt/$i"; done
sudo chroot /mnt
update-grub
exit

At this point your GRUB should be fixed.


I had the same problem and the following fixed it for me:

edit the file /etc/systemd/logind.conf:

sudo nano /etc/systemd/logind.conf

There is a list of entries that define, among other things, delay times for systemd (and systemd-inhibit!)

I uncommented (removed the leading #) from this line:

InhibitDelayMaxSec=5

and saved the file. That immediately remedied the delay. When I close the laptop lid, the system goes to suspend immediately.

Reference - freedesktop.org


"Can not setup lock file:/tmp/g2ipmsg.lock errno : -11 (Resource temporarily unavailable)"

Try to check first about /tmp/ directory and that it is writeable by all users.

Also try this solution :

Type on terminal below command - gsettings set com.canonical.Unity.Panel systray-whitelist "['all']"
Restart and click gnome ip messenger still it may give create lock file error but it will be viewable in notification panel.
If still this doesn't work make sure that you can write to /tmp, try touch /tmp/foo to make sure you can write in it
Next, see whether there is a lock file in /tmp: ls -l /tmp/g2ipmsg.lock if you can't see try with sudo ls -a /tmp/
You can see know who owns the lock file. If there is a lock file, check whether the process is running with pgrep ipmsg.  If not, remove it: rm /tmp/g2ipmsg.lock or sudo rm /tmp/g2ipmsg.lock

Let us know if it worked


Unmet dependencies. Try 'apt-get -f install' with no packages (or specify a solution)

try this :

sudo apt-get clean

or

sudo apt-get autoclean

and run :

sudo apt-get -f install && sudo dpkg --configure -a && sudo apt-get -f install

if result

  0 upgraded, 0 newly installed, 0 to remove and 1 not upgraded.

run  this :

sudo apt-get -u dist-upgrade

and try reinstall package