CMUS Error: opening audio device: No such device I can't seem to play any audio with CMUS because it always gives the error:

CMUS Error: opening audio device: No such device

This is the output of lspci -v | grep -A7 -i "audio":

00:1b.0 Audio device: Intel Corporation NM10/ICH7 Family High
Definition Audio Controller (rev 02)
        Subsystem: ASRock Incorporation Device c892
        Flags: bus master, fast devsel, latency 0, IRQ 49
        Memory at dff00000 (64-bit, non-prefetchable) [size=16K]
        Capabilities: <access denied>
        Kernel driver in use: snd_hda_intel

00:1c.0 PCI bridge: Intel Corporation NM10/ICH7 Family PCI Express
Port 1 (rev 02) (prog-if 00 [Normal decode])

What could be the problem?

If you are using alsa as output, you need to set these:
set output_plugin=alsa
set dsp.alsa.device=default
set mixer.alsa.device=default
set mixer.alsa.channel=Master

Source: Arch Wiki

cmus appears to default to the pulseaudio output plugin.

However the pulseaudio sound system is not necessarily installed on a headless server.

Try :set output_plugin=alsa or :set output_plugin=ao to switch to a supported backend.


GRUB menu not showing with dual-boot UEFI mode installation Previously I had Dell Inspiron Laptop with Legacy Boot and MBR disk partitioning with pre-installed Ubuntu 12.04. I needed dual boot with Windows. So I formatted it completely using Live USB, installed new Windows 8.1 and then installed Ubuntu 14.04, each of Windows and Ubuntu in Legacy mode. When I used to start my laptop, after exiting BIOS it shows GRUB menu where I can choose from Ubuntu or Windows 8.1 options.

Now I have HP Pavilion 15 Laptop which has pre-installed windows 8.1 in UEFI mode and GPT disk partitioning. I installed Ubuntu 14.04 alongside on it and everything is working fine except that I had to pres Esc key as soon as the laptop starts and then pressing F9 - Boot Device Options and then selecting Ubuntu from the menu that appeared. If I don't press F9 it'll directly boot to windows. And no GRUB menu is shown.
Can someone help me how can I get GRUB menu on it?

First try to change the boot order in BIOS (UEFI) settings.
Select Ubuntu to be the default operating system to boot.

If this is not possible boot into Windows and disable hibernation and Fast Boot.

To disable hibernation open command prompt as administrator and execute this command:

powercfg /h off

To disable Fast Boot open Control Panel (the old version - not the modern design),
select the Energy Settings, enable show hidden settings and uncheck Fast Boot.

After having done this shutdown the machine completely - do NOT reboot!

Then reinstall the GRUB boot loader to your Ubuntu installation  in EFI mode.

Boot from the Ubuntu installation media - then  open a terminal and execute:

sudo mount /dev/sd*** /mnt
sudo mount /dev/sd** /mnt/boot/efi
for i in /dev /dev/pts /proc /sys /run; do sudo mount -B $i /mnt$i; done
sudo chroot /mnt
grub-install /dev/sd*
update-grub

Now you can choose which operating system you want to boot from the GRUB boot loader menu.

Note :

sd* = disk | sd** = efi partition | sd*** = system partition

To identify the partition numbers use GParted.
The tool is included in the Ubuntu install media.

I have an HP 11 laptop and also have the same issue. Every time it boots up it shows the HP logo and then goes into Windows 10.
The easiest way to overcome this is to press Esc during startup, or press F9 to directly select the OS. Then you can choose Windows or Ubuntu.


Can't control brightness on Ubuntu 20.04 I installed Ubuntu 20.04 on my Dell Inspiron 11 3162 laptop with 1.6Ghz Intel Celeron 64 bit, 2GB DDR3 and 29GB EMMC storage and it works fine as per my requirements. But I can't control brightness on it.
Its stuck on full.
When I see driver, it shows only dell_backlight. I have tried solutions like adding acpi_backlight=vendor, acpi_backlight=video in grub but it doesn't work. I found solutions for editing files in X11 but its for intel_backlight driver. I have xorg installed but that doesn't help too.
I tried using xrandr commands to set brightness but that doesn't work.
I installed Brightness Controller but that doesn't work either.
My laptop has keyboard keys which control brightness. Unless I set acpi_backlight=vendor the brightness slider and the buttons don't appear. They appear but changing them doesn't reduce/increase brightness.
In settings, it shows unknown display.
The output of lshw indicates Intel display.
There aren't any updates pending for software and drivers, BIOS doesn't have any display related setting.
Dell doesn't have any drivers listed for the laptop for linux.
I installed Linux Mint 20, xubuntu 18.04, lubuntu 18.04 and tried everything above but same problem.
Help.

Use this command kernel --set-brightness 50%. It will command the kernel to change the brightness to your desired %.


In VirtualBox, how do I set up host-only virtual machines that can access the Internet? In setting up virtual machines with VirtualBox, I often want the following characteristics

VM has a static IP
host can access VM without port forwarding
VM can access the internet
I can move my laptop from network to network (e.g. from home to office to coffee shop) without worrying about securing or reconfiguring the VM

None of the VirtualBox network connection methods satisfies these requirements on their own.

NAT
Requires port forwarding if you want to connect to the VM from the host.

Host-only
The VM can not access the internet unless the host is a router.

Bridged
Exposes the VM to the network; not portable.

I can get the setup I want by setting up two adapters on the vm.

VirtualBox 4.2.12
Ubuntu 12.04 guest

In VirtualBox > Preferences > Network, set up a host-only network.

Mine is called vboxnet0, it is manually configured:
ip 192.168.56.1
netmask 255.255.255.0
no dhcp

Then, in the network settings for the virtual machine, set up two adapters:

Adapter 1
host only, vboxnet0

Adapter2
NAT

Boot the virtual machine and log in through the console VirtualBox provides.

Run this to see your adapters:

ls /sys/class/net

In my case the adapters were named eth1 and eth2 (and lo, the loopback interface).

Then, edit your network configuration.

sudoedit /etc/network/interfaces

# The loopback network interface
auto lo
iface lo inet loopback

# Host-only interface
auto eth1
iface eth1 inet static
        address         192.168.56.20
        netmask         255.255.255.0
        network         192.168.56.0
        broadcast       192.168.56.255

# NAT interface
auto eth2
iface eth2 inet dhcp

Note that eth1 has no default gateway specified. eth2 will get a default gateway from dhcp.

Update March 2018

See this answer from @Hugo14453 for an updated version that works with Ubuntu 17.10 and newer.

Yeah I had this problem it was a total pain! But I solved it by simply installing Squid Cache Proxy server on my physical PC, and that way - my host-only internet virtualbox PCs could connect to the internet !
I did a quick 3 minute guide for anyone who wants to know how it works.


Ubuntu-SDK cannot start qtcreator I cannot start qtcreator with ubuntu-sdk installed. I'm getting error:

void DBusMenuExporterPrivate::addAction(QAction*, int): Already tracking action "Follow Symbol Under Cursor" under id 142
loaded the dummy plugin
loaded the Linux plugin
Registered the AalSensorPlugin types

Segmentation fault  (core dumped)

When I removed qtcreator-plugin-ubuntu I was able to start qtcreator. There has to be bug in ubuntu-sdk plugins.

I'm running ubuntu 13.10 64 bit. How to fix it?

First of all , this is possible to do.

core always dumped because of your wrong configuration (i recommend to use i386 ).
simply delete these configuration folders :

rm -rf ~/.config/ubuntu-sdk/

rm -rf ~/.config/Qtproject/

then restart ubuntu-sdk

Finally relax and you're welcome.


Google Chrome cursor and text selection issues after upgrading to google-chrome-stable_41.0.2272.76-1_amd64 I upgraded from google-chrome-stable_40.0.2214.95-1_amd64
to google-chrome-stable_41.0.2272.76-1_amd64 (automatic update on
Ubuntu MATE 14.04 64 bit) and the mouse text selection stopped working
and the cursor icons did not change when hovering over links in the
updated browser, also got an annoying 'Enter you password to unlock
login keyring' prompt when Chrome started.

To eliminate the distro from the mix I also upgraded Google Chrome on
Xubuntu 14.04 64-bit from  Google Chrome 39.0.2171.95-1 to
41.0.2272.76-1 and ran into the same problem.

I tried reinstalling the browser:

  sudo apt-get purge google-chrome-stable
  rm -rf ~/.config/google-chrome
  wget https://dl.google.com/linux/direct/google-chrome-stable_current_amd64.deb
  sudo dpkg -i google-chrome-stable_current_amd64.deb

But the problem still persisted so I downgraded back to the previous
version, this worked, the problems dishappeared:

  sudo apt-get purge google-chrome-stable
  rm -rf ~/.config/google-chrome
  sudo dpkg -i google-chrome-stable_40.0.2214.95-1_amd64.deb

Older versions of Google Chrome can be downloaded from
http://mirror.pcbeta.com/google/chrome/deb/pool/main/g/google-chrome-stable/

See also:

how do I downgrade google chrome?
http://ubuntuportal.com/2014/04/how-to-install-google-chrome-web-browser-in-ubuntu-14-04-lts-trusty-tahr.html

Have you tried the workaround?

sudo cp /usr/share/applications/google-chrome.desktop ~/google-chrome.desktop.bak~
sudo sed -i 's/\/usr\/bin\/google\-chrome\-stable/\/usr\/bin\/google\-chrome\-stable \-\-touch\-devices=123/g' /usr/share/applications/google-chrome.desktop

If this workaround causes problems, use this command to uninstall:

sudo cp ~/google-chrome.desktop.bak~ /usr/share/applications/google-chrome.desktop

Source: https://code.google.com/p/chromium/issues/detail?id=456222#c175

The very same problem which made me to shift on to firefox. It's good but google guys have fixed the problem.
You can try instead the latest version available for firefox as it's far more impressive than Chrome.
http://mozilla_firefox.en.downloadastro.com/


no option for wifi and no working wifi I have installed ubuntu 16.04 but I am not getting wifi option in the menu bar.
I have installed Broadcom 802.11 additional drivers but it made no difference.

What should I do ?

I guess you might have missed to disable the secure boot option. Reinstall the bcmwl-kernel-source package.

$sudo apt-get install --reinstall bcmwl-kernel-source

And the focus on setting the password for disabling secure BOOT.

You then need to restart your system, and press any key to enter into the configuration mode. This screen will only be there for few seconds, so keep your focus while restarting.

You then need to toggle the secure boot option to disable and it will ask for the password you set will installing bcmwl-kernel-source package. It will not directly ask for the password, but ask only certain characters of your password,

For e.g.: Enter Character 2, Enter Character 5, etc.

After that confirmation, the system will boot normally and WiFi drivers should be loaded on your Ubuntu.!

Happy Networking!

Had the same problem with my old HP laptop with old broadcom drivers which might not be supported

Installing B43 and B43legacy drivers from http://linuxwireless.org/en/users/Drivers/b43/ seemed to do the trick for me.

Assuming your model is in their list, just enter in the following command to install and then reboot after.

sudo apt-get install firmware-b43-installer

Note the wifi interface after will be called wls1.

NOTE: There are other driver sets there with install instructions on the site if these aren't your type.


Can I edit which icons appear in the Unity dash? When I open the dash in 11.04, I get two rows of icons.  The first row contains 'lenses' that take me to lists of applicaitons/files; the second row opens specific applications - Browse the Web, View Photos, Check Email, Listen to Music.

Is there any way to change what programs the icons in the second row point to?  (If I were to add new lenses, do they also appear, and can I change the order?)
So far it seems like the Browse the Web and Listen to Music icons respect my preferred applications choices.  The first can be either Firefox or Chromium (and perhaps others) and the second can be either Banshee or Rhythmbox.  However, I can't change the Check Email icon.  It remains pinned to Evolution, even though I have Thunderbird set as my preferred email client.  I'd like to change this if I can.

To change default applications, click the power/settings menu in the top right corner of your screen (the one with the OFF symbol) and select last item (System Settings).

Select Preferred Applications in the window that will appear, so you can change them.

As far as I know, it is not possible to add additional items in the Unity Dash.

"Unfortunately in 11.04 there is no way to arbitrarily change the shortcuts in the dash to any application you want."

To be honest you're not telling the truth ... you can change the entries in the applications menu just as you can change anything on your system ( it's open source people ! ). The problem is that most people don't know where to look ^^.

When it comes to the applications shown in your menu they can all be found under the /usr/share/applications directory. Every entry is of the file-type "*.desktop", these are textual files and you can edit them in vim or gedit ( do know that they're under root, so either chown them or sudo edit them ). If you delete the entry it won't show up in your menu anymore :). As for adding entries, it is just a matter of learning how to write a *.desktop file and placing it in the applications directory.

To learn more about the ".desktop" file format i'll refer you to http://linuxcritic.wordpress.com/2010/04/07/anatomy-of-a-desktop-file/ :) enjoy !

This might be a wee bit archaic ^ ^ but give the open source community a few more months and someone will have written an updated version of alacarte that does this for you :)


Launcher, top bar missing & cannot close, maximize, or move windows I opened my laptop after a month of inactivity (Dell, running 14.04). It was in the suspended state during this time, and upon reopening it, the laptop functioned perfectly. After this initial use, I shut down the laptop. When I booted it the next time, the launcher bar had disappeared along with the top bar, leaving me a blank desktop (only the default ubuntu background remained).

I was able to create a new folder and navigate myself through to the Chromium application. I have made multiple attempts to try and fix this problem with the responses already existing on askubuntu. But my problem remains. I've tried to mess around with ccsm, and tweaking unity, but to no avail.

I have little experience with ubuntu, but I will follow whatever instructions you provide. Please help!

UPDATE I know this question has been marked as a duplicate, but I've honestly tried the solutions on that page. Since the original post, Ive moved to a different wifi zone, and as such am unable to connect to wifi from the computer. I'm posting this update from my phone. I request that those who marked it as a duplicate undo that action because it may prevent my question from being answered.

I too have had this problem on a desktop PC for the past two weeks.  I've tried most of the solutions on the various threads here to no avail.  The launcher disappeared suddenly after a restart following an update.

Finally I decided to experiment.  I created a new user from the terminal and logged in as the new user, Unity and the launcher were working fine for this user.  As SU I copied the .config and .cache files from the new user and overwrote those of the original user, then used chown -R originaluser /home/originaluser/.config and chgrp originaluser /home/originaluser/.config (repeat for .cache) to change ownership.

This approach fixed the problem though it took me quite a while to tweak the original user so that everything works properly.

This seems to be a multi-factorial problem and appears to be worryingly common in 14.04, though I never experienced it in 12.04, which I used since its release until upgrading to 14.04.

In my view this problem is not being taken seriously enough by Canonical, who seem to be viewing it as a glitch or aberration, when it is clearly a worrying instability.

I have yet to have this problem... I would try opening terminal and
using su command to become super.
and deleting the cfg files for unity and compiz to let it rebuild its config.


Software center is not working with proxy I edited the /etc/apt/apt.conf with

Acquire::http::proxy "http://071.12106en068:password@10.1.1.19:80/";
Acquire::https::proxy "https://071.12106en068:password@10.1.1.19:80/";

same with ftp
where 071.12106en068 is my id. Still I am unable to use the software center and it's keep saying check your INTERNET connection

Instead of editing the conf file, try going to System settings in Ubuntu and select Network. Here you can configure the proxy setup for the entire system (see picture below).

Please remember to delete your lines in the conf file first before you do this.


No sound with Philips SAA7130 Hybrid Capture Device card I have put a Philips SAA7130 Hybrid Capture Device card in a PCI slot. Also I have installed TVtime Television Viewer. I have received video, but I can't get audio. Please help step by step to solve the problem.

Sorry for my english .... but i want to help others in this problem

I found a solution for this problem

First we must understand How this card is working, it pipe the sound from the source to the computer sound card, so we can check to see if there is sounds getting out of it bu plugging a head set in the card out ... if there is a sound then the card is working fine

Second we must deal with the input of the sound card, I download a driver of my sound card for linux.

Third i type "alsamixer" in the terminal and make sure automute is disabled and all volume are in high position

Forth i try all different input sockets in the sound card and the sound is working fine

Hope this will be enough

same as above

Trying all the program options and do some googling about this common problem


Unable to remove pgadmin3 version 1.18 from Ubuntu 14.04 I am running Ubuntu 14.04 and have pgadmin3 version 1.18.1, PostgreSQL 9.4 installed.
I am new to pgadmin3.

I want to upgrade to pgadmin3 1.20.0.

So I used

sudo apt-get update
sudo apt-get install pgadmin3

Then I had 2 different versions [1.18.q and 1.20.0] of pgadmin3 installed on my machine.
So I tried to remove pgadmin3 using these commands seperately,

sudo apt-get remove pgadmin3
sudo apt-get remove --auto-remove pgadmin3

also tried,

sudo apt-get purge pgadmin3
sudo apt-get purge --auto-remove pgadmin3

but this removed the 1.20.0 version and not 1.18.1.

I tried removing the 1.18.1 version by using the same commands then it says that the pgadmin3 is not installed.

What should I do to have pgadmin3 version 1.20.0 installed on my machine?
I want to remove version 1.18.1-2.

This is the link to the snapshot which shows that I have 2 versions installed

When I do,

apt-cache show pgadmin3 | grep Version:

it shows,

Version: 1.20.0-3.pgdg14.04+1
Version: 1.20.0-3.pgdg12.4+1
Version: 1.18.1-2

EDIT

Output of,

apt-cache policy pgadmin3

is:

pgadmin3:
  Installed: 1.20.0-3.pgdg14.04+1
  Candidate: 1.20.0-3.pgdg14.04+1
  Version table:
 *** 1.20.0-3.pgdg14.04+1 0
        500 http://apt.postgresql.org/pub/repos/apt/ trusty-pgdg/main amd64 Packages
        100 /var/lib/dpkg/status
     1.20.0-3.pgdg12.4+1 0
        500 http://apt.postgresql.org/pub/repos/apt/ precise-pgdg/main amd64 Packages
     1.18.1-2 0
        500 http://in.archive.ubuntu.com/ubuntu/ trusty/universe amd64 Packages

The output of command,

grep -r 'pgadmin3' /usr/share/applications

is

/usr/share/applications/pg-doc-pgadmin-9_3.desktop:Exec="/opt/PostgreSQL/9.3/scripts/launchbrowser.sh" file:///opt/PostgreSQL/9.3/pgAdmin3/share/pgadmin3/docs/en_US/index.html
/usr/share/applications/pgadmin3.desktop:Exec=pgadmin3
/usr/share/applications/pgadmin3.desktop:Icon=pgadmin3
/usr/share/applications/bamf-2.index:pg-doc-pgadmin-9_3.desktop "/opt/PostgreSQL/9.3/scripts/launchbrowser.sh" file:///opt/PostgreSQL/9.3/pgAdmin3/share/pgadmin3/docs/en_US/index.html         false
/usr/share/applications/bamf-2.index:pgadmin3.desktop   pgadmin3            false

AND
For:

# grep -r 'pgadmin3' ~/.local/share/applications

Output is:

grep: /root/.local/share/applications: No such file or directory

For:

# command -v pgadmin3

it shows:

/usr/bin/pgadmin3

pgadmin version 1.20 is currently installed on your system.

I don't think you've ever had both 1.18 and 1.20 of pgadmin3 installed at the same time.  The icons on the desktop have little relation to the actual installed versions of the applications.

In the case of the pgadmin3 package, the Debian APT package management system prevents you from having more than one version installed at the same time.

When you install an application for which multiple versions are available, look at the output of apt-get install to see the installed version number.

The output of your apt-cache show pgadmin3 output shows that you have 3 versions of pgadmin3 available for installation:

$ apt-cache show pgadmin3 | grep Version:
Version: 1.20.0-3.pgdg14.04+1
Version: 1.20.0-3.pgdg12.4+1
Version: 1.18.1-2
$

(The version 1.20.0-3.pgdg12.4+1 is for Ubuntu Precise 12.4. You should probably remove precise-pgdg from your software sources.)

I hope the following sections help you understand the steps you've been through and what was actually happening:

Default Trusty pgadmin Installation

This is on Trusty 14.04 with pgadmin3 1.18.1-2 installed. Neither trusty-pgdg or precise-pgdg appear in the software sources.

$ apt-cache policy pgadmin3
pgadmin3:
  Installed: 1.18.1-2
  Candidate: 1.18.1-2
  Version table:
 *** 1.18.1-2 0
        500 http://us.archive.ubuntu.com/ubuntu/ trusty/universe amd64 Packages
       100 /var/lib/dpkg/status
$

Show installed versions of pgadmin3:

$ dpkg-query -W pgadmin3
pgadmin3        1.18.1-2
$

Invoke pgadmin3 -v to show the executable version:

$ pgadmin3 -v
pgAdmin III 1.18.1
$

Adding the trusty-pgdg repo (contains newer pgadmin3)

Now I've created a file /etc/apt/sources.list.d/postgresql.list containing the line:

deb http://apt.postgresql.org/pub/repos/apt/ trusty-pgdg main

And then run sudo apt-get update. Looking at the apt-cache policy we see now a new version (1.20.0-3.pgdg14.04+1) from the trusty-pgdg repo. Note the line "Candidate:" which shows which version is the best candidate to be installed:

$ apt-cache policy pgadmin3
pgadmin3:
  Installed: 1.18.1-2
  Candidate: 1.20.0-3.pgdg14.04+1
  Version table:
     1.20.0-3.pgdg14.04+1 0
        500 http://apt.postgresql.org/pub/repos/apt/ trusty-pgdg/main amd64 Packages
 *** 1.18.1-2 0
        500 http://us.archive.ubuntu.com/ubuntu/ trusty/universe amd64 Packages
        100 /var/lib/dpkg/status
$

NOTE: Because there is a new "Candidate", either apt-get dist-upgrade or apt-get install pgadmin3 will install the new version of pgadmin3.

Install pgadmin3 again to get the most recent version from new repo

Now install pgadmin3 again, to get version 1.20 (we already have trusty-pgdg in our software sources list). apt-get install by default attempts to install the latest version, shown by the line "Candidate:" in the policy above:

$ sudo apt-get install pgadmin3
[ . . . ]
Preparing to unpack .../pgadmin3_1.20.0-3.pgdg14.04+1_amd64.deb ...
Unpacking pgadmin3 (1.20.0-3.pgdg14.04+1) over (1.18.1-2) ...
Preparing to unpack .../pgadmin3-data_1.20.0-3.pgdg14.04+1_all.deb ...
Unpacking pgadmin3-data (1.20.0-3.pgdg14.04+1) over (1.18.1-2) ...
[ . . . ]
Setting up pgadmin3-data (1.20.0-3.pgdg14.04+1) ...
Setting up pgadmin3 (1.20.0-3.pgdg14.04+1) ...
[ . . . ]
$

And verify the installed version:

$ dpkg-query -W pgadmin3
pgadmin3        1.20.0-3.pgdg14.04+1
$

$ pgadmin3 -v
pgAdmin III 1.20.0
$

Also shown by apt-cache policy:

$ apt-cache policy pgadmin3
pgadmin3:
  Installed: 1.20.0-3.pgdg14.04+1
  Candidate: 1.20.0-3.pgdg14.04+1
  Version table:
 *** 1.20.0-3.pgdg14.04+1 0
        500 http://apt.postgresql.org/pub/repos/apt/ trusty-pgdg/main amd64 Packages
        100 /var/lib/dpkg/status
     1.18.1-2 0
        500 http://us.archive.ubuntu.com/ubuntu/ trusty/universe amd64 Packages
$

If you try to install again, no action will be taken:

$ sudo apt-get install pgadmin3
Reading package lists... Done
Building dependency tree
Reading state information... Done
pgadmin3 is already the newest version.
0 upgraded, 0 newly installed, 0 to remove and 0 not upgraded.
$


PCI error messages on Lenovo B50-10 Recently I've installed Ubuntu LTS 16.04 on a new Lenovo B50-10 laptop. Apparently everything is working properly, however some error messages apppears regarding pci devices on dmesg.

dmesg |grep fail

[    1.268776] pci 0000:00:1c.0: BAR 14: failed to assign [mem size 0x00200000]
[    1.268789] pci 0000:00:1c.0: BAR 15: failed to assign [mem size 0x00200000 64bit pref]
[    1.268803] pci 0000:00:1c.1: BAR 15: failed to assign [mem size 0x00200000 64bit pref]
[    1.268830] pci 0000:00:1c.1: BAR 15: failed to assign [mem size 0x00200000 64bit pref]
[    1.268839] pci 0000:00:1c.0: BAR 14: failed to assign [mem size 0x00200000]
[    1.268852] pci 0000:00:1c.0: BAR 15: failed to assign [mem size 0x00200000 64bit pref]

And some other messages like this:

[    0.537659] pci 0000:00:1c.1: BAR 15: no space for [mem size 0x00200000 64bit pref]

I've searched this errors on google, and everything indicates it could be a bios bug.  Beside, a related error message appears on dmesg output, as you can see above:

[    2.867219] pci 0000:00:1d.0: EHCI: BIOS handoff failed (BIOS bug?) 01010001

I've updated the bios with the new version available on Lenovo support site, v2.07 at this point, released on Oct-2016, but the problem remain.
If I pass the option 'acpi=off' to the kernel, no error messages appears, but wifi card doesn't work.
If a fix 'OS Optimized default' to Enabled on Bios, and hit 'Load default settings', the errors remain.

IMHO, everything is related with a bios bug. In the past, I've suffered a similar problem with a Lenovo b50-30, but in that case, a bios update fixed the problem.

Any help would be appreciate.

Thans in advance,

Best Regards.

run the firmware test suite, fwts klog test on a freshly booted system, it may explain some of those error messages:

apt-get install fwts
fwts klog -

Thank you for the answer!. I paste the result, not very useful info:

Results generated by fwts: Version V16.03.00 (2016-03-14 09:10:20).

Some of this work - Copyright (c) 1999 - 2016, Intel Corp. All rights reserved.
Some of this work - Copyright (c) 2010 - 2016, Canonical.

This test run on 18/12/16 at 01:03:27 on host Linux lenovo 4.4.0-53-generic
#74-Ubuntu SMP Fri Dec 2 15:59:10 UTC 2016 x86_64.

Command: "fwts klog -".
Running tests: klog.

klog: Scan kernel log for errors and warnings.
--------------------------------------------------------------------------------
Test 1 of 1: Kernel log error check.
Kernel message: [ 0.030056] ENERGY_PERF_BIAS: Set to 'normal', was 'performance'

ADVICE: This is not exactly a failure but a warning from the kernel. The
MSR_IA32_ENERGY_PERF_BIAS was initialized and defaulted to a high performance
bias setting. The kernel has detected this and changed it down to a 'normal'
bias setting.

Kernel message: [ 0.164916] [Firmware Bug]: ACPI: BIOS _OSI(Linux) query ignored

ADVICE: This is not exactly a failure mode but a warning from the kernel. The
_OSI() method has implemented a match to the 'Linux' query in the DSDT and this
is redundant because the ACPI driver matches onto the Windows _OSI strings by
default.

FAILED [CRITICAL] KlogAcpiNoValidCrt: Test 1, CRITICAL Kernel message: [
1.473105] [Firmware Bug]: No valid trip found

ADVICE: No valid ACPI _CRT (Critical Trip Point) was found.

Found 1 unique errors in kernel log.

================================================================================
0 passed, 1 failed, 0 warning, 0 aborted, 0 skipped, 0 info only.
================================================================================

0 passed, 1 failed, 0 warning, 0 aborted, 0 skipped, 0 info only.

Test Failure Summary
================================================================================

Critical failures: 1
 klog: CRITICAL Kernel message: [    1.473105] [Firmware Bug]: No valid trip found

High failures: NONE

Medium failures: NONE

Low failures: NONE

Other failures: NONE

Test           |Pass |Fail |Abort|Warn |Skip |Info |
---------------+-----+-----+-----+-----+-----+-----+
klog           |     |    1|     |     |     |     |
---------------+-----+-----+-----+-----+-----+-----+
Total:         |    0|    1|    0|    0|    0|    0|
---------------+-----+-----+-----+-----+-----+-----+


How to install libc6:i386 on 16.04.4 64bit? I've been trough all the similar questions I can find on here and elsewhere but still can't get a working solution for this.

Things I've tried:

apt-get install libc6:i386

This tries to remove most of the currently installed 64bit libraries that if run would leave the machine unusable.

I've run the following based on other questions/answers and still no joy:

dpkg --add-architecture i386
apt-get update
apt-get upgrade
apt-get dist-upgrade

All complete cleanly but don't change the output of trying to install the 32bit libraries.

The next option was to try:

apt-get install libc6-i386

Which returns:

The following packages have unmet dependencies,
 libc6-i386 : Depends: libc6 (= 2.23-0ubuntu3) but 2.23-0ubuntu10 is to be installed
E: Unable to correct problems, you have held broken packages

This error appears misleading as apt-mark showhold returns no packages.

The end goal here is to install Symantec's AV package which needs the 32bit libraries.

Make sure you have enabled all sections in Software & Updates and selected good mirror (I prefer Main server) in

Ubuntu Software

and security-updates in Updates:

Then sudo apt-get install libc6:i386 will be enough.

Or deeper:

sudo apt-get update
sudo apt-get dist-upgrade
sudo apt-get install libc6:i386
sudo apt-get install -f

On my system libc:i386 is installed with version 2.23-0ubuntu10.

add x32 architecture
$ sudo dpkg --add-architecture i386
next! - rebuild your libs in repo
$ sudo apt --fix-broken install
next -> try to install your package
$ sudo dpkg -i xxx1.deb


Allocate Disk Space FROM Ubuntu for Windows I want to dual boot Windows and Ubuntu from my computer, which has only Ubuntu installed. I have done dual booting before but in that case, Windows was installed first. Here are my Ubuntu partitions:

And I want to free up some 60GB space for my Windows. How do I do that?

It is inadvisable to modify mounted partitions.
Thus, You should boot from a LiveCD or USB.

First make a back up of your data in case of problems.

Use gparted to shrink your home partition.
Then create a partition for the windows install.
Boot the windows installer. and install it to the partition.

Note: windows will write a bootloader to EFI/boot/bootx64.efi. If you use device boot, Grub will need to be put back in.


How to run openssh-server compiled from source I have compiled openssh source using
./configure
make and
make install

Now it has compiled and installed binaries, config files and the server at

/usr/local/bin
/usr/local/etc
/usr/local/sbin

what's next?. How do I start the ssh server and start connecting to it?

I guess, you must have found the answer by now.
but if not then run the following:

# sudo /usr/local/sbin/sshd

In some distributions, the sshd file will be located elsewhere, e.g., /usr/sbin/sshd

This will start the openssh server with default settings, but in a few cases it will show an error:

privilege separation user sshd does not exist

To resolve this error, run the following commands before compiling OpenSSH:

sudo install -v -m700 -d /var/lib/sshd
sudo chown -v root:sys /var/lib/sshd
sudo groupadd sshd
sudo useradd  -c 'sshd PrivSep' -d /var/lib/sshd -g sshd -s /bin/false -u 50 sshd

see if you can do sudo service ssh start, if it does and you want it to run on startup you can also do sudo update-rc.d ssh defaults to always run it on startup.

then from another machine (linux/mac) try ssh username@machine-ip. On windows you can use putty providing machine ip.


Unsafe swap space detected So I had a Ubuntu 13.04 installation and I had encrypted my hard drive while I was doing installation. I was playing around and mistakenly deleted all the partitions, now I downloaded lUbuntu 13.10 x86 Desktop but when I am trying to install it says "Unsafe swap space detected"

I am clueless on how to fix this error.

Try to boot via "Try Ubuntu" instead of "Install Ubuntu" and run the command:

sudo swapoff --all

From the terminal. (ctrl+alt+t)

Then run the Install Ubuntu from the desktop. The error should stop appearing.

See also this related Lubuntu/ubuntu bug report

It is this Bug That still exists in Lubuntu 14.04.2 Desktop i386 version. That's what i've tested - maybe this safe's some other people's nerves.

I got it working using the alternate-cd (14.04.1 i386) but there you need to make sure to select the "Install" method - not the "expert install" and not "install lubuntu" and when grub asks you to install to MBR say "No" because that is another bug and you will then be given the option to specify the correct device to install grub to.

Made a detailed answer specified for 14.04 now: Link

Greets

An


Dell G3 15 only recognizes external monitor, laptop screen black I have Dell G3 15 and I have installed Ubuntu 18.04 and at first my second monitor was not working.

I have installed the nvidia driver as such:

And after I performed this tutorial: http://ae0bq.org/?p=137

At this point only my second hdmi connected display seems to work. My laptop display remains black.

I aslo tried switching from gdm3 and lightdm with the same output. Under wayland, on gdm3 I was able to work on my laptop display but not on the hdmi connected one.

How can I make both displays work? (there is no hardware failure)

I had a similar issue after my Nvidia Driver create a /etc/X11/xorg.conf   file containing only Nvidia monitor (external ones) configurations. Since there was no further configuration of internal monitor (which don't use nvidia drives) the computer was only working with the external ones.
To fix it i only deleted the file /etc/X11/xorg.conf. I hope it fix your issues

May be a dumb question but are you sure your display is enabled ? Settings -> display (I guess mine in french is "Affichage")

What happens when you unplug your external monitor ?


How do I increase the resize margin on windows? It takes me about 5 tries to resize a window on my computer.

Is there a way to increase the resize margin on the edge of windows?

As others have mentioned, it depends on the theme. Try a few out. What I frequently do instead is hold down Alt and middle-click (right-click in some environments) and drag to resize, which works anywhere on the window.

Note that many themes that seem to have a 1px border (or no border at all) actually do tend to have a generous invisible border just outside the window. You usually don't have to pinpoint a tiny window border to resize.

Alt+MiddleButton is the right way to resize windows; it's right are your hands, and you don't have to move the pointer to the window edges first.

However, I still find that the scroll overlay often gets in my hair.  So I went for a different approach and disabled the overlays all together!  Scroll still works, of course, and the nice orange scroll indicator is still present.  On Ubuntu 13.04, I did it like this:

gsettings set com.canonical.desktop.interface scrollbar-mode 'overlay-touch'

You can revert it by doing:

gsettings set com.canonical.desktop.interface scrollbar-mode 'overlay-auto'


How to use Unity Dash in Gnome classic? I am wondering if there is a way to use Unity Dashboard in Gnome-classic? If yes, what are the dependency packages need to be installed?

UPDATE:

Or is there any app could do that?

There's Currently no way to use the Dash without Unity being active so here's an alternative.
elementary's Slingshot.

Slingshot launcher is developed by the Elementary team. Here is how to install Slingshot launcher in Ubuntu Natty from elementary team ppa.

Add the PPA ppa:elementaryart/elementary-dev and install slingshot-launcher from the software center.
To use it you simply have to create a launcher in the Gnome Panel with the command slingshot, the same goes for AWN.

Source.

I don't know exactly what you're trying to accomplish, but it is possible to run gnome-panel and Unity at the same time. Just don't use the upper gnome-panel, because that will create conflicts with the Unity panel. So just delete the upper panel and add gnome-panel to your startup applications, and you will have both.


Installing 11.10 on flash drive failed Possible Duplicate:
  How do I install Ubuntu to a USB key?

This is my problem. I burned Ubuntu 11.10 iso to a CD. I was able to boot my PC with it. I plugged in my flash drive, and inserted the CD and restarted the computer to boot Ubuntu.

I then chose to install Ubuntu alongside with Windows (XP prof.). Then I was able to select my flash drive as the installation location. I prepared partitons by dragging a bar and allocating the size for the Ubuntu installation, and for other files. I set 3GB for ubuntu and 1GB for other files. The  pen drive was partitioned and files installed on it. After sucess I ejected the CD to restart the PC to use the new OS.

When it restarted I expected to be asked to select an OS to boot. But I could only boot with Windows XP. Properties of my flash drive show its total capacity is 1GB. The partitioned 3GB is missing.

How can I boot with the USB stick?
How can I get my 4GB USB stick back?

I'm pretty sure you have to boot from bios again and choose boot from us drive again.
Or enter into bios and set for boot from usb or cd first before harddrive options.

Edit: You have to just install ubuntu on the usb flashdrive.
Reinstall ubuntu to the flashdrive not boot alongside windows xp.
So make sure your flashdrive is mounted

See the problem is that the boot loader probably doesn't know anything about Ubuntu. I am guessing GRUB knows about Windows, but it isn't being loaded first. My guess is you need to get into the Windows boot laoder and make a configuration change in there.


USB key - folder parameters - changing access rights There is an MS Windows computer in my lab, which is sadly infected by some strange trojans and viruses. One USB key got into trouble while it was plugged on to the computer. Scanning with an antivirus (McAfee) removed all the viruses.

I put this particular USB key into my linux machine and I was able to see all the folders. However, on a Windows machine, these folders and files were not visible.

By issuing attrib -h -s * I was able to make some of the files visible. However, the folders won't still be visible.

Is there any Linux command with which I could make these folders visible again on the Windows machine?

Why don't you just examine the folders in Linux?

Also, I'd be certain to scan the Windows machine that you plugged the USB key into.


How do I cancel a time-delayed  screenshot? I'm using the default screenshot application that comes with Ubuntu gnome-screenshot

When I was using it earlier to take screenshots of the lock screen I had set a long time delay, but forgot to change it back after I'd finished. When I next took a timed screenshot I had to wait a long time for it to take because the delay was still set so long.

Clicking the icon to relaunch the screenshot application has no effect whilst the timer is in effect, I imagine there is probably a simple terminal command to shut down an application, but I don't know it! Is there a way to do this?

The one-liner you're looking for is:

kill `pidof gnome-screenshot`

  pidof is preferable here compared to pgrep, killall and some invocations of ps, which only consider the first 15 characters of a command name and can choke on hyphens. Be careful not to kill the similarly prefixed gnome-screensaver if you use these..

Step1. Looking for the process numbers of gnome-screenshot by ps ax command in the terminal.

Step2. Execute kill <process_number>.

Step3. Insert the following command from the terminal:

gnome-screenshot -i

Then, you can set Grab after a delay 0 second.


No more sound after running Ardour All the sound works perfect with all the applications on my system. But from the moment I launch Ardour, no more sound comes out from other application than Ardour. The easy way to get it back is to restart the laptop.

This is probably related to Jack ... but it's not clear...

Does anyone know what's going on behind the scene? How to fix it?

in Terminal:$ top | grep jackd, first number in line will be the pid of JACK, kill it with $ kill <pid>. It's the simplest way)

Just to share the way I wrote the command to kill jackd:

sudo killall jackd


Ubuntu 12.10 won't fully load I want to try Ubuntu from my 16GB stick without ditching Windows 7 just yet.

Everything boots up fine, I get the spash screen, I get the question screen (Try Ubuntu or install).

I select try ubuntu and then my screen goes black with what appears to be a prompt.
No keyboard keys work at this time.
Have tried re-downloading Ubuntu, rebooting, bu nothing seems to work.

The problem is that Ubuntu will not boot properly with an older graphics card, flash drive, RAM , and what version of intel or AMD you have. If it still does not boot some computers like some newer laptops or even older ones to might not be compatable with OS due to slave drives.


How do I upgrade Gradle? This shows that Gradle is up to date:

thufir@doge:~$ sudo apt install gradle
Reading package lists... Done
Building dependency tree
Reading state information... Done
gradle is already the newest version (2.10-1).
0 upgraded, 0 newly installed, 0 to remove and 629 not upgraded.

How do I upgrade to Gradle 4.x?  Preferably, with umake rather than SDKMAN! which seems to be what they suggest.

(I don't want to update all the packages due to a slow connection.)

You could use the ppa for the almost-always latest version

sudo add-apt-repository ppa:cwchien/gradle
sudo apt-get update
sudo apt upgrade gradle

or SDKMAN for the latest version

curl -s "https://get.sdkman.io" | bash
source "$HOME/.sdkman/bin/sdkman-init.sh"
sdk install gradle

Advantages of the ppa

auto-updates with the system
no piping of downloaded scripts to the shell

Advantages of sdkman: latest version supplied by gradle themselves.

download from  https://gradle.org/releases/

pick the binary-only link as per

  v4.10.3

  Dec 05, 2018

  Download: binary-only or complete

after you expand the download just update your PATH env var to pickup this new binary

vi ~/.bashrc  # or where ever your shell's env vars are defined

and add following line to bottom of ~/.bashrc

#   replace ~/src/gradle-4.10.3/bin with your location
export PATH=~/src/gradle-4.10.3/bin:$PATH

confirm this works by issuing

source ~/.bashrc
gradle --version


Failed to access Windows 8.1 NTFS partition from Ubuntu 13.10, even after disable fast startup I am using Ubuntu 13.04, 32 bit and Windows 8.1. When I try to mount Windows 8.1 NTFS Partition it is showing this error message as below. Previously I was using Windows 7, but I have no problem to mount that partition. I tried to follow this answer and do as follows with Windows 8.1

Solution: Windows 8

There is a new feature in Windows 8 called Fast Startup. If this feature is enabled (which it is by default), Windows 8 does not actually completely shutdown when you choose "shutdown". Instead, it does a "hybrid shutdown". This is something like hibernating; it makes booting Windows 8 back up faster. So, you need to disable this feature to be able to shut it down properly, and be able to mount the Windows partitions. To do this, boot into your Windows 8 and:

Note: disabling Fast Startup will most likely make your Windows 8 take a longer time to boot. There are no "exact" numbers, but let's say that if it took you 10 seconds to boot into Windows 8, it will now take you 50 seconds after disabling this feature.

Open Control Panel in the small icons view and click on Power Options.
Click on Choose what the power buttons do.
Click on Change settings that are currently unavailable.
Uncheck Turn on fast startup (recommended).

Click on Save changes. Now, shutdown Windows 8 and boot back into Ubuntu. You'll be able to mount without getting errors.

But I can not mount Windows 8.1 partition even after I done this. Can anyone help me, please! The error message is

  Error mounting /dev/sda2 at /media/rashed/Windows 8.1: Command-line `mount -t "ntfs" -o "uhelper=udisks2,nodev,nosuid,uid=1000,gid=1000,dmask=0077,fmask=0177" "/dev/sda2" "/media/rashed/Windows 8.1"' exited with non-zero exit status 14: Windows is hibernated, refused to mount.
    Failed to mount '/dev/sda2': Operation not permitted
    The NTFS partition is in an unsafe state. Please resume and shutdown
    Windows fully (no hibernation or fast restarting), or mount the volume
    read-only with the 'ro' mount option.

I solved this problem by running  powercfg /h off in windows command terminal. This command usually disable windows hibernate permanently. I follow this instruction and now I have full access of windows partition.

By changing the permission in Windows 8 you can fix this problem. I have faced same problem as you faced. It is solved after providing the full access to the all user. I do not have any idea to the other consequences in Windows by doing this.


How do I install Dell 2150cdn printer Love Ubuntu but cannot get printer to work. It's a Dell 2150cdn colour laser printer.

I went to settings and tried to add printer and tried all various options but they alll jang for over an hour. Tried in both Gnome and KDE. Chose option to install openprint but it does not load, just hangs.

Loaded openprint fron software centre but doesnt seem to make any difference.

Searched web and found dell PDL file, d/led and installed. Printer works but does not print documents, just lots of blank pages with 1 line of symbols on some of them.

Went to dell site and d/l'd driver file but also makes no difference.

Stuck now and need to get printer working or forced to retreat back to windoze.

Any advice?

Cheers

Brian

There's a longish article at How to install Dell 2150cdn on Ubuntu, but it seems more like something written for an internal user at a corporation.  However, they did seem to get your printer running, so there's hope!


HDD error when mounting When I plug in my external hard disk drive I get this error message:

Error mounting /dev/sdf1 at /media/makermex/Seagate Expansion Drive:
Command-line `mount -t "ntfs" -o
"uhelper=udisks2,nodev,nosuid,uid=1000,gid=1000,dmask=0077,fmask=0177"
"/dev/sdf1" "/media/makermex/Seagate Expansion Drive"' exited with non-zero exit status 18: Failed to open $MFT/$BITMAP: No such file or directory
Failed to load $MFT: No such file or directory
Failed to mount '/dev/sdf1': No such file or directory

I was looking for information about the error but I can't find anything, do you know how I can solve this please ?

You could try this:

     blkid

and this gives you some info, and this you can use in /etc/fstab

you can also do this:

     1 | greb -f $a1

and you can also use gparted from software-center.


Removing CrossOver Games from Unity Start panel I'm new to Ubuntu and  recently installed CrossOver Games Trial on Ubuntu 12.04, didn't like it, tried to uninstall it but simply refused to go away , so I just went on and deleted the folders in the File System.

Problem is that now there are 4 icons left on the Unity Start Panel under "installed applications", and I don´t know how to remove it. Actually, could anyone tell me how to delete any shortcut that is created on the Start Panel? Is there a way to do it?

Thank you very much!

The shortcut that you are talking about are called .desktop files.  They are in one of two places.

/usr/local/share/applications

or

home/.local/share/applications   Note that the .local is a hidden file so you will need to show hidden files Ctrl+h to see them

Most likely the files are in the usr/local so you will need to use sudo to delete them.

When you delete these .desktop files they will no longer show up in your Dash under Installed applications but will still show up in the recent history until you open enough other programs to push them out.


3 TB hard drive suddenly no longer recognized My 3TB Western Digital WD30EXRX hard drive that used to work perfectly fine, is suddenly no longer being recognized properly. It isn't mounted automatically anymore, the file manager does not recognize it at all and in gnome-disks it is shown as an empty hard drive with 802GB of free space.

What could possibly be a reason for this and what can I do to repair the disk/recover the data?

Your drive is most probably suffering from corrupt firmware and the drive will need to be set back to its native/default capacity.

HDD Capacity Restore Tool will be able to help you with that.


Lag in keyboard response in 16.04 I recently went to a full install of Ubuntu 16.04 LTS. (I was dual booting for a while) and now there are no other operating systems on my laptop. So I have it on my hp -2000 laptop that is a few years old but still has a 400g hard drive and 12g of ram.  I do notice though if I have had the laptop on for a while (say from 8am till about 12pm) It starts to act sluggish. Keystrokes are delayed is really the biggest issue. If I power cycle it comes back good as new and there is no issue. Is this a problem other folks have had? Is it just my bad laptop?

In a case like this, I'd plug in an external USB-based keyboard and see if the sluggishness is on that one, too.  If the problem follows that external keyboard then it could be that your computer is sluggish because it's busy.

I'd then try to figure out what it is that's making my computer busy.

How do you find out which program is using too much memory?  So maybe you could consider running something like gnome-system-monitor, for example, which might give you some insight into what's running.  If this is related to a processor-hog stealing all its time then this could help.

If it's a bad driver then I'm not sure I'm the right guy to help.


Set manual IPv4 on 18.04-2 server install I just tried to install Ubuntu server 18.04-2 and wanted to set IPv4 manually. I entered all the required data as subnet, ip, gateway and so on. But after I saved it all my data disapeared and it jumped back again to keyboard selection.

I seems as installation process just dont saves the manual IP settings.

Does anyone have the same experience?

Yep, seems to be an issue with that live version of the server iso.

Try http://cdimage.ubuntu.com/releases/18.04.2/release/ - using the standard text installer worked for me.

Yes On Setup Disabled the Network

[Disabled IPv4][1/3]

[Disabled IPv4][2/3]

[Disabled IPv4][3/3]

Finish Setup and configure IP static

sudo vi /etc/netplan/50-cloud-init.yaml

[IP Static]

# This file is generated from information provided by
# the datasource. Changes to it will not persist across an instance.
# To disable cloud-init's network configuration capabilities, write a file
# /etc/cloud/cloud.cfg.d/99-disable-network-config.cfg with the following:
# network: {config: disabled}
network:
    ethernets:
        ens160:
            dhcp4: no
            addresses:
            - 192.168.XX.XXX/24
            gateway4: 192.168.XX.1
            nameservers:
                addresses:
                - 192.168.XX.XX
                - 192.168.XX.XX
                search
                -DOMAIN
            optional: true
    version: 2


How to play a 3d video properly? I have a video in mkv format that shows two identical separate videos together, and not one over the other in vlc. On windows, I am able to play it adjusting deep, 3d mode (red cyan, with 3d TV and its glasses thorugh hdmi), etc.
Bino does not work at all. I can only select rec cyan and it crashes on full screen. I am using ubuntu 11.10 with fully 3d support.

Probably your MKV file uses MVC encoding, which is a special mode of H264. As of 2016 there is no pure linux solution for amd64/x86 platform (the wikipedia article lists software for Windows/Wine).
If you own a RaspberryPi you can use omxplayer, which is capable of decoding MVC.

Normally an anaglyph (3D via red/blue glasses) video has to be a single file containing both color filters. You could use a video editor (there are many open source video editors available for Linux) to combine your two video files and export to a single anaglyph video file.


Failed to get canonical path of /cow I am trying to install Ubuntu 12.10 for quite some time, and passing hurdles one by one. Now I am in a situation as follows.

I have got a PC and 10 GB HDD which will be totally dedicated to Ubuntu so no option of Wubi and dual boot.

I was trying to install from DVD, but it is getting stuck at "Out of frequency" error. So I had to adapt for USB boot option. But my PC is USB non bootable, so workaround is "Plop Boot Manager". So I am doing the installation procedure as follows:

starting  from a CD drive which is having plop installed.
opting for for USB boot in plop options.
booting begins from USB.
monitor eventually gives "out of frequency" error
press Shift+Alt+F1 to get the terminal.
open the grub with sudo nano /etc/default/grub.
do necessary changes.
sudo update-grub.

Now here I am getting error as follows:

/usr/sbin/grub-probe:error:failed to get canonical path of /cow.

My system is

P4 3.06 GHz, 1 GB ram , 10 GB HDD without an OS, monitor CRT lg StudioWorks (7 years old). Mobo Mercury P4 266a NDMx (865 equivalent). The whole system is perfectly in working condition under XP, but it is USB non bootable, and all other devices working perfectly.

What should I do next?

After booting from the Ubuntu live CD (tried 14.04 and 16.04) I was able to work around this problem by running update-grub chroot'ed to the grub partition.  (Substitute /dev/sda1 below with whatever partition you installed grub on. All commands as root.)
mkdir /mnt/chrootdir
mount /dev/sda1 /mnt/chrootdir
for dir in proc dev sys etc bin sbin var usr lib lib64 tmp; do
    mkdir /mnt/chrootdir/$dir && mount --bind /$dir /mnt/chrootdir/$dir
done
chroot /mnt/chrootdir
grub-install /dev/sda # May not be required
update-grub2

It is the update-grub command which will give you the error when using it from a live cd. I faced with a similar situation when I was doing a GRUB rescue. Also grub-install wasn't in my path for some reason, so I had to run it with /usr/sbin/grub-install.
grub-install accepts a --boot-directory option, to set up GRUB to boot to a system different from the one that is currently running. Here is the relevant manual page.


How do I install Tk 8.5? Where can I find the Tk packages?

$ sudo apt-get install tk8.5
Reading package lists... Done
Building dependency tree
Reading state information... Done
Package tk8.5 is not available, but is referred to by another package.
This may mean that the package is missing, has been obsoleted, or
is only available from another source

E: Package 'tk8.5' has no installation candidate

these are the results I have produced with the help of apt-cache search tk8.5

frank@august:~$ apt-cache search tk8.5
tk8.5 - Tk toolkit for Tcl and X11, v8.5 - run-time files
tk8.5-dev - Tk toolkit for Tcl and X11, v8.5 - development files
tk8.5-doc - Tk toolkit for Tcl and X11, v8.5 - manual pages

you worth a try with sudo apt-get update and then retry with installation.

else you can choose the package from your results of apt-cache search , as i have mentioned above.

try this:

sudo apt-get install Tk8.5

Tk has a capital "T" in front.  That worked for me.


How to set default opening folder for Nautilus file manager? How do I configure Nautilus to open at my Documents folder instead of my home folder?

I've scoured this site and found answers instructing users to edit the /usr/share/applications/nautilus.desktop file, replacing %U with the path to the desired default directory. I've edited all the variants of nautilus.desktop in the said directory, but none of the edits has an effect. I've checked all the files after editing them to make sure that I saved the edit effectively, and all look good to me.

I've edited every file to read as follows:

Exec=nautilus --new-window /home/judy/Documents

I've also edited the org.gnome.Nautilus.desktop file, just to be sure, with no joy.

I'm running Ubuntu 15.10.

Note: if I enter nautilus /home/judy/Documents from the command line, Nautilus properly opens in the desired directory.  Is there a simple way that I can configure an icon in the launcher bar to run this command and have the Nautilus icon that looks like a metal file drawer?

Thanks. I'm pulling my hair out over this one.

The file that is shown in unity-dash is not anymore /usr/share/applications/nautilus.desktop but /usr/share/applications/org.gnome.Nautilus.desktop.

Changing the Exec= line in the file itself does not have any effect.
The problem is an entry DBusActivatable=true that makes the system to run nautilus via dbus. So the Exec= line is being ignored. Maybe it is possible to provide nautilus the desired directory through dbus (/usr/share/dbus-1/services/org.gnome.Nautilus.service) but I am not familiar with that system in detail.
For further information look here: https://wiki.gnome.org/HowDoI/DBusApplicationLaunching

A simple solution for me was to hide the gnome/dbus launcher-icon and make the old one visible again. So add the entry NotShowIn=Unity; to /org.gnome.Nautilus.desktop and comment it out in nautilus.desktop. There you can adjust the Exec= line with the desired directory.

(file: org.gnome.Nautilus.desktop)

[Desktop Entry]
NotShowIn=Unity;     # <--------------------------- add this line !
Name=files
Comment=Access and organize files
Keywords=folder;manager;explore;disk;filesystem;
Exec=nautilus --new-window %U
Icon=system-file-manager
Terminal=false
Type=Application
DBusActivatable=true
StartupNotify=true
Categories=GNOME;GTK;Utility;Core;FileManager;
MimeType=inode/directory;application/x-gnome-saved-search;
X-GNOME-Bugzilla-Bugzilla=GNOME
X-GNOME-Bugzilla-Product=nautilus
X-GNOME-Bugzilla-Component=general
X-GNOME-Bugzilla-Version=3.14.2
X-GNOME-UsesNotifications=true
Actions=Window;
X-Unity-IconBackgroundColor=#af4853
X-Ubuntu-Gettext-Domain=nautilus

#OnlyShowIn=Unity;    # <---------------- comment out this line !

[Desktop Action Window]
Name=Open a New Window
Exec=nautilus --new-window
#OnlyShowIn=Unity;    # <---------------- comment out this line !

(file nautilus.desktop)

[Desktop Entry]
#NotShowIn=Unity;     # <---------------- comment out this line !
Name=files
Comment=Access and organize files
Keywords=folder;manager;explore;disk;filesystem;
Exec=nautilus --new-window /{DESIRED_DIRECTORY}     # <- adjust !
Icon=system-file-manager
Terminal=false
Type=Application
StartupNotify=true
Categories=GNOME;GTK;Utility;Core;FileManager;
X-GNOME-Bugzilla-Bugzilla=GNOME
X-GNOME-Bugzilla-Product=nautilus
X-GNOME-Bugzilla-Component=general
X-GNOME-Bugzilla-Version=3.14.2
X-GNOME-UsesNotifications=true
Actions=Window;
X-Unity-IconBackgroundColor=#af4853
X-Ubuntu-Gettext-Domain=nautilus

[Desktop Action Window]
Name=Open a New Window
Exec=nautilus --new-window

There is a simpler way:

Create an empty file in your desktop.
Open it with a text editor, such as gedit.
Write the following lines:

[Desktop Entry]
Name="Open Nautilus in custom folder"
Exec="nautilus /path/to/custom/folder"
Type=Application

Save it as nautilus_custom.desktop.
Open a terminal and run:

chmod +x $HOME/Desktop/nautilus_custom.desktop

Without quotes. Now you should be able to start Nautilus in you custom folder by double-clicking the file you've just created in your desktop.


How to install psql without Postgres? I need the psql command line tools, but I don't need the actual Postgres RDBMS. This is to work with a package which supports a psql interface.

Is it possible to install just psql?

(Ubuntu 16.04)

Oh, yes:

$ sudo apt-get install -y postgresql-client
$ psql --version
psql (PostgreSQL) 9.5.12

If you don't want to install anything, just download the package
https://www.enterprisedb.com/download-postgresql-binaries

Then run unpack and run ./bin/psql
No installation.

The package also contains postgres server which you can run at local without installation also. For more, ref https://www.golery.com/pencil/vU


Gnome-shell can't install - broken packages I am trying to install gnome-shell but it shows me an error:

$ sudo apt-get install gnome-shell

...

Some packages could not be installed. This may mean that you have
requested an impossible situation or if you are using the unstable
distribution that some required packages have not yet been created
or been moved out of Incoming.
The following information may help to resolve the situation:

The following packages have unmet dependencies:
 gnome_shell : Depends: gnome-settings-daemon (>= 3.4.0) but it is not going to be installed
               Recommends: gnome-control-center but it is not going to be installed
E: Unable to correct problems, you have held broken packages.

OP's original screenshot

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

sudo apt-get -f install

sudo apt-get install gnome-shell

From comments:

$ sudo apt-get install -f gnome-shell gnome-control-center gnome-settings-daemon
The following information may help to resolve the situation:

The following packages have unmet dependencies:
 gnome-settings-daemon : Depends: gnome-settings-daemon-schemas (= 3.12.2-0ubuntu1~trusty3) but 3.8.6.1-0ubuntu11.2 is to be installed
E: Unable to correct problems, you have held broken packages.

Installation

Please do the following. Open up a terminal and start with:

sudo apt-get clean

followed by

sudo apt get update && sudo apt-get upgrade

If you got errors continue with

sudo apt-get -f install

Finally finish with

sudo apt-get install gnome-shell

Login to Gnome

I am assuming you are using lightdm

If that worked out, logout and choose 'Gnome' for the next login-session in the login-manager and login again.

Open up a terminal and run

sudo apt-get install gnome-shell gnome-control-center gnome-settings-daemon


Is there a music player like Winamp? I'm looking for a music player similar to Winamp.

There's no software in Linux like the current Winamp. If you want something almost similar, try Audacious, BUT the skined interface ONLY supports winamp 2.x skins. I came from a Winamp environment so I can say this, forget about skins and use the default GTK interface and you'll like it, I know I did :)

Try Tomahawk. It's a next generation music player. You can call it social music player. It has got great interface. It's feature rich. You will make it your default music player after testing it. It's my challenge. Tomahawk website


Is there a way to change the highlight colour in 16.10? I looked at other answers about changing the orange highlight colour, but they all seem to apply to earlier versions. Using dconf-editor and modifying gtk-color-scheme (either through terminal or GUI) doesn't appear to work in 16.10

So, is it still possible?

why don't you try terminator. in this terminal you can highlight text easily.

this is the web site where you find more information.
https://gnometerminator.blogspot.in/p/introduction.html


Copy text from website using keyboard Do anyone know of an web application that makes it possible to copy text easily from the web browser using keyboard? E.g. like vimium works for selecting links in the web browser using keyboard.

Edit: to be more specific. How to highlight and copy from web browser using only the keyboard, and not the mouse.

Sorry for being unprecise.

You need caret browsing.

press F7 for enable to caret browsing.
open browsing window then press tab button, then select text using arrow keys. Finally ctrl+c and ctrl+v.

Highlight the text and push ctrl+c and hit ctrl+v where you want to paste the text.
?

Most web-browsers come with the ability to simply right-click a link and either copy the link address to memory or open in a seperate window/tab.


Should I install ATI propriety video drivers on Ubuntu 11.04 on my Dell Inspiron 9100? I have a Dell laptop, Inspiron 9100, with a ATI Technologies Inc RV350 [Mobility Radeon 9600 M10] video card. The video performance has always been pretty poor in Ubuntu. Though slightly improved in 11.04. Symptoms are video tearing on full screen, stuttering images due to low refresh rates.

I have read about the ATI propriety drivers with catalyst. On the web there seems to be those for and against propriety drivers and also some problems (sometimes serious) after installing the propriety drivers.

Would you recommend it?
Will it help video performance?
What are the risks (i.e. will I end up with a blank-screened brick)?

I would recommend it only if you are using 3D Applications which have a poor performance or simply don't work with the open source drivers.
Yes it increases the performance (a lot).
You can always boot into the recovery mode and install the open source drivers (if you have a blank screen or stuff like that). See https://wiki.ubuntu.com/X/Troubleshooting/FglrxInteferesWithRadeonDriver#Problem:__Need_to_fully_remove_-fglrx_and_reinstall_-ati_from_scratch for detailed instructions.

a) No. ATI dropped support for older cards in 2008, including your Mobility Radeon 9xxx. This means that the Catalyst/FGLRX driver from ATI will NOT work properly with your card.

b) Very unlikely. Even if you are lucky and the driver would work and get anything from your card, it is doubtful the performance will be any good, because, as I've already said, the support for 9xxx was dropped a long time ago.

c) The risks are very small though, if you try to install it won't do any harm to your hardware, but if the driver won't work, Ubuntu should enter a lo-fi graphics mode with a res of 800x600 or similar, so you will be able to deactivate the driver and fall back to the open-source one. Alternatively you may be unable to start the X server, but you can boot in the rescure mode and disable the driver from command line.

Concluding, your card is simply too old, and ATI does not care about you - they want you to buy a new one. However, the open-source driver developers do care about old cards, so the only way you can get anything from your card is to use the default, open-source driver.


Wubi: Permission denied: 'C:\\boot.ini' I got a problem with installing ubuntu with the help of wubi.
My configuration is a laptop with single hdd, Windows XP SP3 and my user account with admin rights. Wubi version is rev245.

I can manually change the file boot.ini (and I already removed the read-only flag) but wubi always crashes with the following error:

Traceback (most recent call last):
File "\lib\wubi\application.py", line 58, in run
File "\lib\wubi\application.py", line 132, in select_task
File "\lib\wubi\application.py", line 158, in run_installer
File "\lib\wubi\backends\common\tasklist.py", line 197, in __call__
File "\lib\wubi\backends\win32\backend.py", line 606, in modify_bootini
File "\lib\wubi\backends\common\utils.py", line 239, in write_file
IOError: [Errno 13] Permission denied: 'C:\\boot.ini'

I added the following line manually

c:\wubildr.mbr="Ubuntu"

but I am stuck with a grub shell bootloader that doesn't recognize any kernels (as these files weren't copied).

Is there a switch to tell wubi to proceed even if it can't access boot.ini perhaps?

Thank you for your help!

Try to login to the account with administrator permissions instead of just selecting Run as
.. Administrator.

Right click>run as>USERNAME>Untick the box underneath  worked for me


Is there a power saving application similar to Jupiter? I'm trying to install the Jupiter power settings app but, I read it is no longer compatible with the new kernel. Is there a similar program or a way to manage the power settings on 13.04?

Improve Power  Usage / Battery Life In Linux With TLP

Overview

TLP brings you the benefits of advanced power management for Linux without the need to understand every technical detail. TLP comes with a default configuration already optimized for battery life, so you may just install and forget it. Nevertheless TLP is highly customizable to fulfil your specific requirements.

Features

Kernel laptop mode and dirty buffer timeouts
Processor frequency scaling including "turbo boost" / "turbo core"
Power aware process scheduler for multi-core/hyper-threading
Hard disk advanced power magement level and spin down timeout (per disk)
SATA aggressive link power management (ALPM)
PCI Express active state power management (PCIe ASPM) – Linux 2.6.35 and above
Runtime power management for PCI(e) bus devices – Linux 2.6.35 and above
Radeon KMS power management – Linux 2.6.35 and above, not fglrx
Radeon dynamic power management – Kernel 3.11 and above, not fglrx
Wifi power saving mode – depending on kernel/driver
Power off optical drive in drive bay (on battery)
Audio power saving mode – hda_intel, ac97

Also Check Additional functions

Installation

Also Check Prerequisites

sudo add-apt-repository ppa:linrunner/tlp
sudo apt-get update
sudo apt-get install tlp tlp-rdw smartmontools ethtool

ThinkPads

sudo apt-get install tp-smapi-dkms acpi-call-tools tlp tlp-rdw smartmontools ethtool

tlp-rdw – Radio Device Wizard - Need to enable/disable & Power saving (Wifi / Bluetooth )
smartmontools - needed by tlp-stat to display disk drive S.M.A.R.T. data
ethtool - needed to disable wake on lan
tp-smapi-dkms ThinkPad only, tp-smapi is needed for battery charge thresholds and ThinkPad specific status output of tlp-stat
acpi-call-tools ThinkPad only, acpi-call is needed for battery charge thresholds on Sandy Bridge and newer models

Additional

TLP Indicator for Unity
A Unity Indicator created to comfortably switch between AC and BAT Modes.
Use it at your own risk.
Download here: indicator-TLP.py

Configuration

Removing default Ubuntu cpu frequency config

sudo update-rc.d -f ondemand remove

TLP Developer

( This is not a general prerequisite for TLP but is only needed if the user decides to change the default governor. If a user issues the command without changing the TLP setting too, he ends up with "perfomance", which is quite bad for battery life.), Apply to section 3.) Processor and Frequency Scaling

The main config file of TLP is at /etc/default/tlp

sudo -i gedit /etc/default/tlp

Parameters

General hints

Parameters ending on _AC are effective with the power supply connected
Parameters ending on _BAT are effective when running on battery
Parameters containing blanks must be enclosed in double quotes like this: ""
Some parameters are inactive by default; remove the leading '#' to activate

0.) General

TLP_ENABLE=1

Set to 0 to disable TLP (Reboot needed), It should be enabled so leave the default value

1.) File System

   DISK_IDLE_SECS_ON_AC=0
   DISK_IDLE_SECS_ON_BAT=2

DISK_IDLE_SECS_ON_BAT=2 = You can either leave the default value (2) or you can edit it as 5, By default Ubuntu uses 5, its up to you, read the gives below help

cat /usr/lib/pm-utils/power.d/laptop-mode

This controls how agressive the system is at trying to avoid
writing to disk.  The longer the disk is idle, the more power you can save.

This is only active on battery power, and it restores these values
to kernel defaults when on AC power.

Defaults 5, which enables laptop mode and forces the system to wait
5 seconds whenever something asks to write to disk to flush out as much
data as we can.

2.) Dirty page values

MAX_LOST_WORK_SECS_ON_AC=15
MAX_LOST_WORK_SECS_ON_BAT=60

Leave the default value

Defaults 60, which means that the kernel will not start forcing process
to write out file information that has been changed but not saved until 60%
of usable system memory is filled with dirty information.

3.) Processor and Frequency Scaling

CPU_SCALING_GOVERNOR_ON_AC=ondemand
CPU_SCALING_GOVERNOR_ON_BAT=powersave

Remove the hash and edit it as conservative.

Its up to you what you want, you can also use ON_BAT=powersave

Select a cpu frequency scaling governor: ondemand/powersave/performance/conservative

Governor ??

The governor decides what frequency should be used.

Module Description:

ondemand        Dynamically switch between CPU(s) available if at 95% cpu load

performance     Run the cpu at max frequency

conservative    Dynamically switch between CPU(s) available if at 75% load

powersave       Run the cpu at the minimum frequency

TLP Developer

To use "conservative" over "powersave – especially on AC – should not be
a general recommendation but only an option for hardware that produces
excessive heat or fan noise.

4.) Min/Max frequency

#CPU_SCALING_MIN_FREQ_ON_AC=0
#CPU_SCALING_MAX_FREQ_ON_AC=0
#CPU_SCALING_MIN_FREQ_ON_BAT=0
#CPU_SCALING_MAX_FREQ_ON_BAT=0

Set the min/max frequency available for the scaling governor.
Possible values strongly depend on your cpu. For available frequencies see
tlp-stat output, Section "+++ Processor".

Hint: Parameters are disabled by default, remove the leading # to enable them,
otherwise kernel default values are used.

5.) Turbo Boost

CPU_BOOST_ON_AC=1
CPU_BOOST_ON_BAT=0

Set the cpu "turbo boost" feature: 0=disable / 1=allow ,Requires an Intel Core i processor and kernel 3.7 or later.

Important:
This may conflict with your distribution's governor settings, A value of 1 does not activate boosting, it just allows it

6.) Cpu Cores/Hyper-Threads

SCHED_POWERSAVE_ON_AC=0
SCHED_POWERSAVE_ON_BAT=1

Minimize number of used cpu cores/hyper-threads under light load conditions

7.) Kernel

NMI_WATCHDOG=0

Activate kernel NMI watchdog timer (0 = disabled/save power, 1=enabled). A value of 1 is relevant for kernel debugging only.

8.) Hard disk advanced power management level

DISK_APM_LEVEL_ON_AC="254 254"
DISK_APM_LEVEL_ON_BAT="128 128"

Set the "Advanced Power Management Level". Possible values range between 1 and 255:

1 – max power saving / minimum performance

Important: this setting may lead to increased disk drive wear and tear because of excessive read-write head unloading (recognizable from the clicking noises)

128 – compromise between power saving and wear (TLP standard setting on battery)

192 – prevents excessive head unloading of some HDDs

254 – minimum power saving / max performance (TLP standard setting on ac)

255 – disable APM (not supported by some disk models)

Different values for multiple disks are separated with blanks.

9.) Disk I/O Scheduler

#DISK_IOSCHED="cfq cfq"

Select io scheduler for the disk devices: noop/deadline/cfq (Default: cfq)
Separate values for multiple devices with spaces.

noop is often the best choice for memory-backed block devices (e.g. ramdisks) and other non-rotational media (flash) where trying to reschedule I/O is a waste of resources

deadline is a lightweight scheduler which tries to put a hard limit on latency

cfq tries to maintain system-wide fairness of I/O bandwidth

10.) SATA aggressive link power management (ALPM):

min_power/medium_power/max_performance

SATA_LINKPWR_ON_AC=max_performance
SATA_LINKPWR_ON_BAT=min_power

ALPM
Aggressive Link Power Management (ALPM) is a mechanism where a SATA AHCI controller can put the SATA link that connects to the disk into a very low power mode during periods of zero I/O activity and into an active power state when work needs to be done. Tests show that this can save around 0.5-1.5 Watts of power on a typical system. ( For more check " Sources and additional help " )

11.) PCI Express Active State Power Management (PCIe ASPM):

( default/performance/powersave )

Hint: needs kernel boot option pcie_aspm=force on some machines

PCIE_ASPM_ON_AC=performance
PCIE_ASPM_ON_BAT=powersave

12.) Radeon graphics clock speed

(profile method): low/mid/high/auto/default

auto = mid on BAT, high on AC; default = use hardware defaults (Kernel >= 2.6.35 only, not with fglrx driver!)

#RADEON_POWER_PROFILE_ON_AC=high
#RADEON_POWER_PROFILE_ON_BAT=low

13.) WiFi power saving mode

1=disable/5=enable

(Linux 2.6.32 and later, some adapters only!)

WIFI_PWR_ON_AC=1
WIFI_PWR_ON_BAT=5

14.) Disable wake on lan

Y = Yes , N = No

WOL_DISABLE=Y

15.) Audio power saving for Intel HDA

Enable audio power saving for Intel HDA, AC97 devices (timeout in secs). A value of 0 disables / >=1 enables power save.

SOUND_POWER_SAVE=1

  Disable controller too (HDA only): Y/N

SOUND_POWER_SAVE_CONTROLLER=Y

16.) Power off optical drive in UltraBay >> (ThinkPads only)

Set to 1 to power off optical drive in UltraBay (ThinkPads only), when running on battery. A value of 0 disables this Feature (Default). Drive can be powered on again by releasing (and reinserting) the eject lever or by pressing the disc eject button on newer models. Note: an UltraBay hard disk is never powered off.

BAY_POWEROFF_ON_BAT=1

  Optical drive device to power off (default sr0)

BAY_DEVICE="sr0"

17.) Runtime Power Management for pci(e) bus devices

RUNTIME_PM_ON_AC=on
RUNTIME_PM_ON_BAT=auto

  Runtime PM for all pci(e) bus devices

RUNTIME_PM_ALL=1

Runtime PM for all pci(e) bus devices: 0=disable / 1=enable, Warning: experimental option, could cause system instabilities

Some times my usb mouse dongle didn't work when i plug it in usb 3 port, work fine when i plug it in usb 2 port, and all my usb 3 devices are working properly no issue.

18.) Usb autosuspend

Set to 0 to disable/1 to enable usb autosuspend feature

USB_AUTOSUSPEND=1

19.) System Start and Shutdown

RESTORE_DEVICE_STATE_ON_STARTUP=0

Restores radio device state (builtin bluetooth, wifi, wwan) from previous shutdown on system startup:

0 – disable, 1 – enable

DEVICES_TO_DISABLE_ON_STARTUP="bluetooth wifi wwan"

Disables builtin radio devices upon system start:

bluetooth
wifi – Wireless LAN
wwan – Wireless Wide Area Network (UMTS)

Multiple devices are separated with blanks.

I have an error that my Blue tooth device is not Disabled on start up, so if you face this problem just do the following config

sudo nano /etc/rc.local

And add the following line before exit 0

rfkill block bluetooth

Save & Exit & Reboot

Working with TLP

After installation TLP will be automatically activated upon system start.

To start it immediately without reboot or to apply changed settings use:

sudo tlp start

Use the tlp-stat terminal command to check if TLP is working properly

sudo tlp-stat

Check You system temperature

sudo tlp-stat -t

Show battery information only:

sudo tlp-stat -b
sudo tlp-stat --battery

Show configuration only:

tlp-stat -c
tlp-stat --config

Show radio devices switch state only:

tlp-stat -r
tlp-stat --rfkill

Show temperatures and fan speed only:

tlp-stat -t

Apply Battery Settings (ignoring the actual power source):

sudo tlp bat

Apply AC Settings (ignoring the actual power source):

sudo tlp ac

You can check Which I/O you are using.

sudo tlp-stat  # Check the section +++ Storage Devices

Trace Mode

To examine suspected problems in TLP more closely, activate trace mode in /etc/default/tlp:

TLP_DEBUG="lock nm path pm rf run sysfs udev usb"

Add above mentioned line in the end /etc/default/tlp , The accumulated trace data may be read at any time with

tlp-stat -T

Or

grep "tlp" /var/log/debug

In case the trace output is missing, you have to modify your rsyslogd configuration. Create the file /etc/rsyslog.d/90-debug.conf containing

*.=debug;\
auth,authpriv.none;\
news.none;mail.none -/var/log/debug

And restart the daemon

sudo /etc/init.d/rsyslog restart

Sources and additional help

There is very good support at TLP Website

Useful Config Link 1

TLP Settings

ALPM

Optional tweaks

Tweak your CPU frequency with indicator-cpufreq

Installation

indicator-cpufreq will help you change your CPU frequency on the go:

sudo apt-get install indicator-cpufreq

Go to Dash > search for Startup > edit indicator-cpufreq add -f or copy paste the following command:

indicator-cpufreq -f

Screenshot

With the indicator you will be able to monitor your current CPU frequency & can change CPU frequency

Changing CPU frequency

Click on indicator

Additional Advice
VA-API (Hardware Acceleration For Intel / AMD GPUs)

Overview

The main motivation for VA-API (Video Acceleration API) is to enable hardware accelerated video decode/encode at various entry-points (VLD, IDCT, Motion Compensation etc.) for the prevailing coding standards today (MPEG-2, MPEG-4 ASP/H.263, MPEG-4 AVC/H.264, and VC-1/VMW3). Extending XvMC was considered, but due to its original design for MPEG-2 MotionComp only, it made more sense to design an interface from scratch that can fully expose the video decode capabilities in today's GPUs.

Help full Links
webupd8

Official Intel Drivers are using VA-API

Support video codecs

Install Intel / AMD VA-API drivers in Ubuntu

for Intel GPUs (for Intel HD Graphics as well as G45 and later):

sudo apt-get install i965-va-driver libva-intel-vaapi-driver vainfo

for AMD Radeon GPUs (you also need the proprietary drivers!):

sudo apt-get install xvba-va-driver vainfo

  Install MPlayer with VA-API support in Ubuntu

By default, the MPlayer version available in the official Ubuntu repositories doesn't support VA-API, but you can use a PPA which provides custom MPlayer builds with VA-API support.

sudo add-apt-repository ppa:sander-vangrieken/vaapi
sudo apt-get update
sudo apt-get install mplayer-vaapi

Now you need to install smplayer or vlc

sudo add-apt-repository ppa:rvm/smplayer
sudo apt-get update
sudo apt-get install smplayer

OR

sudo apt-get install vlc

Configuration

SMPLAYER

Its in Option tab > Preferences, on the Video tab > General Video > Output driver set the video output driver to "vaapi":

VLC

Its in Tools > Preferences > Input & Codecs > Enable Use GPU Accelerated decoding

Helpful Links

How to correctly enable/test VA-API on Intel Sandy Bridge?
Command line flag for mplayer to use hardware acceleration?

PowerSavingTweaks for Intel Graphics

sudo nano /etc/default/grub

change:

GRUB_CMDLINE_LINUX_DEFAULT="quiet splash"

to:

GRUB_CMDLINE_LINUX_DEFAULT=""quiet splash intel_pstate=disable i915.lvds_downclock=1 drm.vblankoffdelay=1 i915.semaphores=1 i915_enable_rc6=1 i915_enable_fbc=1"

and run:

sudo update-grub

Helpful Links

3x+ battery life

I'd like to add auto-cpufreq to the list. It's a new automatic CPU speed and power optimization tool for Linux laptops using Intel CPUs. Support for AMD CPUs is being worked on.

This command line tool automatically changes the CPU frequency scaling, governor (switches between performance and powersave, these being the only 2 modes supported by the nowadays default intel_pstate scaling driver) and turbo boost status based on various information gathered from your computer, like the battery state, CPU usage and system load. (source: Linux Uprising)

The installation instructions below come from its Github page:

Install dependencies:

sudo apt install git python3-dev python3-pip python3-distro python3-psutil python3-click python3-power -y

On Ubuntu versions older than 19.10:

pip3 install --upgrade psutil click distro power

Grab auto-cpufreq from Git:

git clone https://github.com/AdnanHodzic/auto-cpufreq.git

Run auto-cpufreq

cd auto-cpufreq

sudo python3 auto-cpufreq.py --live

--live enables auto-cpufreq so you can see how your system behaves with the new settings, but it doesn't make these settings permanent.

To make it permanent, use the --install option (so the changes persist across reboots; this installs the auto-cpufreq daemon and systemd service):

sudo python3 auto-cpufreq.py --install


Login screen goes black on 15.10 First I just want to say I consider myself a beginner using Ubuntu.  I've read through most of the forums I could find which were related to this my problem and couldn't find a method which works.

Here's what happens.  When I hear the login screen sound, I see nothing but black. If I type my password to login and I hear the sound associated with logging in but the screen still stays black. If I close my laptop screen to go into sleep mode and then open it back up, the login screen is visible but then goes black after I login. I tried recovery mode and repairing packages but didn't work. I tried no splash and nomodeset but the screen just froze. Ran a system diagnostic and it gave this error message:

for my video drive. I think the issue might have to do with the nVidia drivers I switched to before.  Is there a way to fix this? Thx in advance for any help.

i had a similar issue when i installed ubuntu as a virtual machine.
I was able to get the gui screen using Ctrl-F7.
Ctrl key was the right side ctrl key.
You can try this combination of Ctrl-Alt-F7.
something similar to this Switching Between GUI and Terminal


ssh id_rsa.pub not accessible I have a problem when i try to use a key with ssh:

ssh  -i /ssh/id_rsa.pub root@xxx.xxx.xxx.xxx
Warning: Identity file /ssh/id_rsa.pub not accessible: No such file or directory.

/ssh is not a valid file path, and if it is you don't have access to view it.

SSH Keys are usually generated and placed into $HOME/.ssh/.  I think you meant to run this:

ssh -i $HOME/.ssh/id_rsa root@x.x.x.x

Does root on the remote machine have a password?  That is, did you sudo passwd root to give root a password on the remote machine?  If you didn't do that, you can not log in as root directly.

For an Ubuntu install, root's home is /root.

You should not need the -i flag unless you have multiple ssh identities in /root/.ssh.


How to start Chrome always in "Incognito Mode"? So... I found a solution to be able to open Chrome on 12.04 in Incognito Mode by default (How do I make Google Chrome open Incognito by default?).

I can't seem to get it to open consistently in Incognito Mode with all the pages I have set to load on startup e.g. In OS X, I open Chrome, which defaults to Incognito Mode and loads all the websites I have set in the "Open a specific page or set of pages" preference. In Ubuntu I can't replicate that.

In Ubuntu/Linux unless you edit the .desktop file it won't work. Run the following:

sed 's/\/google-chrome/\/google-chrome --incognito/g' /usr/share/applications/google*.desktop

Is not efficient but will do the work.


What is the use of /boot (lvm based) in partitioning? As separate /home partition helps in easy reinstallation/upgrade. Does having /boot help while dualbooting with windows? I mean is it useful for normal desktop/notebook users or it is advanced technique that need to be deployed in servers?

[The information in this answer about GRUB2 and LVM is largely due to Jan's efforts; originally this answer was severely in error, and Jan deserves credit for the improvements I have made. -Eliah]

When not using LVM, a separate /boot partition is primarily useful for ensuring that the files necessary for booting are close enough to the beginning of the drive, when the / partition is itself not at the beginning of the drive. For example, you might want to put your linux-swap partition very near the beginning of the drive, since on some drives data near the beginning of the drive is potentially accessed more quickly. Then you could have a small /boot partition, followed by your linux-swap partition, followed by the / partition (then followed by other separate partitions if you have them, such as /home).

For quite some time, this has been largely unnecessary, because with newer BIOSes, you can usually boot a system whose boot files are in a partition far from the beginning of the disk. Still, there is very little disadvantage to doing so (unless you make /boot so small that it fills up--it should probably be about 250 MiB), so many people who partition manually still do this.

Older boot loaders like LILO themselves had limitations that made separate /boot partitions helpful, as Jan points out.

When using LVM, if your / partition is on the LVM, it used to be necessary to have a separate /boot partition. In such a configuration, the /boot partition is not be a partition of the LVM, but rather a partition on the disk before the LVM starts. This is because boot loaders could not read files from an LVM. So you could never boot into your system on the LVM if it didn't have a separate /boot partition (see this and this for details).

The ability to read files from an LVM was added with GRUB2, which means that all recent versions of Ubuntu (Ubuntu 9.10 Karmic Koala and later) have it. So with proper configuration you can have your entire Ubuntu system in an LVM without a separate /boot partition. See this page for details about how to configure this. (In fact, the only currently supported Ubuntu release that uses the original GRUB instead of GRUB2 is Ubuntu 8.04 LTS Server; every other non-EoL release--10.04 LTS, 10.10, 11.04, and 11.10--uses GRUB2.)

If you're using LVM but not for your Ubuntu system drive, just for a storage drive, or for some part of your system (perhaps for /home) but not /, then a separate /boot partition is not necessary, even if you are using an old (pre-GRUB2) system.

In summary, a separate /boot partition is largely a matter of personal preference for systems that do not use LVM, whereas an older system installed on an LVM might need one.

You can a should also use a single /boot partition when installing multiple distributions ( as well as a single swap partition ).
None of those distributions own 100% of the /boot info so /boot should not be in any partition of a single distribution.


Script to add multiple users in ubuntu (Bulk) I need to add 10 users by a script in Ubuntu 12.04.

That could reduces time by adding users manually , and i can apply this script on other
desktop .

Each user will has a specific user and in specific group.

Any idea?

Open a terminal and type: vim /tmp/name to create a file and the names of the users: eg:

vim /tmp/name
mika
mery
etc

Create User with Home Dir and default shell:

for i in `cat /tmp/name`; do useradd -m -d /home/$i -s /bin/bash $i; done

Create password for each user:

for i in `cat /tmp/name`; do passwd $i; done

It is my solution. I created file /tmp/userlist and added all users name, after completion of script it will create users and you can find user name and given random password in file /tmp/userlist-created. I know it is not perfect solution.

root@demobox:/root : cat /tmp/userlist
xyz1
zyz2
zyz3

root@demobox:/root : cat demo.sh
#!/bin/bash

if [ -f /tmp/userlist ]
then
for i in $(cat /tmp/userlist)
do
if [ -f /usr/bin/pwgen ]
then
PASSWORD=$(pwgen -1 -s 16)
else
PASSWORD=$(cat /dev/urandom | tr -dc "passwordNSR!@#$%0-9" | fold -w 9 | head -1)
fi
useradd -s /bin/bash -d "/home/$i" -m -p "$PASSWORD" "$i"
echo "$i --------- $PASSWORD" >>/tmp/userlist-created
done
else
echo "File /tmp/userlist not found"
fi
chmod 0600 /tmp/userlist-created

root@demobox:/root : ./demo.sh

root@demobox:/root : cat /tmp/userlist-created
xyz1 --------- FivSHfdbDCRffhc7
zyz2 --------- AIjFjE0bv3FslHnp
zyz3 --------- JazcGcKYp2Y0I3Rk

root@demobox:/root : egrep "xyz1|zyz2|zyz3" /etc/passwd
xyz1:x:9016:100::/home/xyz1:/bin/bash
zyz2:x:9017:100::/home/zyz2:/bin/bash
zyz3:x:9018:100::/home/zyz3:/bin/bash


Unable to boot from cd or live usb on Toshiba satellite U945-S4140 I am trying to completely switch over to ubuntu from a my toshiba ultrabook. Link to product page: http://www.toshiba.com/us/computers/laptops/satellite/U940/U945-S4110
I previously had linux mint dual booted with windows 8, and to get that to work my friend had to do something to the computer. I have the iso for ubuntu 14.04 LTE loaded onto a cd, and I have tried starting my computer with my external usb disk drive, but I keep getting the message "Reboot and Select proper Boot device or Insert Boot Media in selected boot device and press a key" even though I have the UEFI set up to boot from my cd drive. I was able to previously install ubuntu, but right at the end of the install the bootloader failed to install correctly. How should I proceed to be able to join the ubuntu family?

In order to install from a USB device you may need to include a USB installer on the media. Doing so will allow your computer to recognize the media as bootable. You may be able to use the same process used to make a bootable pendrive. Try going to www.Ubuntu.com/download/desktop/create-a-usb-stick-on-windows. I did this process with a 2 GB pen drive and got a successful install. However, I also had to ensure my computer was set to recognize the drive as an external hard drive and set it to top priority in the boot sequence.


Lenovo z470 getting hot, after 12.04 install When I was using Windows 7 my notebook temperature was very good, it stayed very cool. After I installed 12.04, my notebook base is hot all the time, I cannot even put my hands on it for a long time.

My notebook has a 2nd generation Intel i5 processor. I installed Jupiter and it shows 72 Degrees Celsius constantly.

Anyone got a fix for this? I don't want to go back to windows but if I do not find any solution I will have to do it.

I'd be very grateful for any help.

I have the same laptop, the problem is the Optimus technology, there is not exist support from Nvidia on LInux. But I fixed that problem by installing Bumblebee, from bumblee project  just following the instructions on its wiki.

This patch, software can enable or disabled the nvidia graphics and use Intel driver, It's amazing because your laptop never will be Hot again and your batery life will be better,

https://github.com/Bumblebee-Project/Bumblebee/wiki/Install-and-usage Wiki in General

https://wiki.ubuntu.com/Bumblebee Wiki for Ubuntu

i have Lenovo X121 with Ubuntu 12.04. I have the same Problem but i have figured it makes a difference when you use Unity 2D. I probably save the GPU, so the Temperature goes down is well. To start Ubuntu Unity 2D, log off and click on the circle like ubuntu sign next above to the place where you enter the password, a drop down list will appear, choose unity 2D. You might also want to try out a lightweight desktop. however... i figured that temperature goes up dramatical fast when a popup buble tool tip appears, so this made me clear its the unity desktop which uses 3d enhancement which makes the cpu run hot

sry for my bad english, i am german


Software Center Crash 13.04 I'm having problems with the Ubuntu Software Center, when I try to open it, after two seconds it closes. I've tried reinstalling it but I keep getting this when I try sudo apt-get update:

W: Failed to fetch http://ppa.launchpad.net/software-store-developers/ppa/ubuntu/dists/raring/main/binary-amd64/Packages  404  Not Found

W: Failed to fetch http://ppa.launchpad.net/software-store-developers/ppa/ubuntu/dists/raring/main/binary-i386/Packages  404  Not Found

E: Some index files failed to download. They have been ignored, or old ones used instead.

Thanks!

Those messages aren't really errors. They are simply telling you that that PPA does not support your version of Ubuntu. They are not preventing you from just running sudo apt-get install software-center which will still work.

Remove that PPA (deb http://ppa.launchpad.net/software-store-developers/ppa/ubuntu raring main) from your sources. It is no longer in use. Updated versions of software-center are provided via the Ubuntu One team's PPAs:

ppa:ubuntuone/stable
ppa:ubuntuone/beta
ppa:ubuntuone/nightlies

These PPAs include the Ubuntu One client packages, Software Center, and any necessarily updated dependencies. However, the version of software-center in Ubuntu 13.04 is still pretty much up to date, as it was only released a couple months ago.

you can add them by copy and pasting them into the other software tab of the software and updates section of system settings. Click the gear in the top right corner to get to system settings.


What hardware does Ubuntu Touch support? With the announcement of the Ubuntu Phone OS I'd like to know what phone (and tablet) models are supported at this time.

Note from foss & Oli: We are making this the master question for all future "Will this work on <insert random tablet/phone/device here>?!" questions

Note that Canonical ended development of Ubuntu Touch and any work on phones in April 2017.

Supported Devices

Nexus 4
Nexus 7 2013 WiFi
BQ Aquaris E4.5 (announcement)
BQ Aquaris E5 (announcement)
BQ Aquaris M10 (announcement)
Meizu MX4 (announcement)
Meizu PRO 5 (announcement)

Previously Supported Devices

Galaxy Nexus
Nexus 7 (2012)
Nexus 10

These devices have been deprecated and further development & updates may longer be available.

Porting to Other Devices

Directly quoting from the Ubuntu Wiki (obsolete URL removed!):

  We want to port Ubuntu Touch to all kinds of devices. If you have experience in porting code to Android devices or are generally knowledgeable in terms of porting, working with the Kernel and other core bits and pieces of a distribution, this might be interesting to you.

Moreover, there's really no way to tell which future devices people will choose to work on, however there is a working list of devices that the community is working to enable here:

https://devices.ubuntu-touch.io/

Release Notes in the blog

Be sure to check for Known Issues before you proceed.
And Device Specific Issues as well.

Applications Available

  The Developer Preview comes with the following functioning applications:

  Gallery
  Phone (Dialler, SMS, Address Book)
  Camera
  Browser
  Media Player
  Notepad
  Music app
  Calculator
  Weather app

Installing Applications

Download application from store. Supported Application can be found in App-Store!
Or you can use The SDK to create an application of your own.

Only for Evaluation

Quoting from Ubuntu Wiki (obsolete URL removed!):

  The Touch Developer Preview project provides the open source code for enthusiasts and developers, to familiarise themselves with Ubuntu's phone and tablet experience and develop applications on spare devices.

  It is currently work in progress and intended for enthusiasts who want to contribute testing and building the platform.

Further quoting from their Install page (obsolete URL removed!):

  It does not provide all the features and services of a retail phone and cannot replace your current handset.

  This process will delete all data from the device. Restoring Android will not restore this data.

So be sure to do a complete backup before venturing out.

Flashing the device

Head here for instructions on flashing your device.

What to expect after flashing

  Shell and core applications
  Connection to the GSM network (on Galaxy Nexus and Nexus 4)
  Phone calls and SMS (on Galaxy Nexus and Nexus 4)
  Networking via Wi-Fi
  Functional camera (front and back)
  Device accessible through the Android Developer Bridge tool (adb)
  Daily use of the phone
  Advanced usage

More Ubuntu Touch Documentation

NOTE: This answer was quite old, with many obsolete URLs! Many of them are migrated and that data not available on newer portal, I have tried to keep original answer as it is with this edit. Help this answer to serve better!

Canonical gives its specifications on the Operator and OEM Partner page.