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I'm running linux clusters, mostly on SLES10. The servers are mostly blades, accessed via remote console. There is a real console in the server room, but switched off.

I would like to disable the screen blanking as it serves no purpose and is a nuisance. You have to press key to see if you are connected which is a pain. We are running in runlevel 3, so the console is in text mode, no X11 involved.

Caleb
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markus_b
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  • SLES10 uses SysV init. Many distributions use systemd, [here's a possible solution for Arch](http://superuser.com/questions/278396/systemd-does-not-run-etc-rc-local/462828#462828). [Debian 6 and 7 systems use kbd by default, click here](http://superuser.com/a/935833/76876). – basic6 Jul 03 '15 at 09:45
  • For Debian, see https://unix.stackexchange.com/questions/238846/ . – JdeBP Oct 10 '18 at 14:16

10 Answers10

95

You can verify what timeout the kernel uses for virtual console blanking via:

$ cat /sys/module/kernel/parameters/consoleblank
600

This file is read-only and the timeout is specified in seconds. The current default seems to be 10 minutes.

You can change that value with entering the following command on a virtual console (if you are inside an xterm you have to change to a virtual console via hitting e.g. Ctrl+Alt+F1).

$ setterm -blank VALUE

Where the new VALUE is specified in minutes. A value of 0 disables blanking:

$ cat /sys/module/kernel/parameters/consoleblank
600
$ setterm -blank 0
$ cat /sys/module/kernel/parameters/consoleblank
0

setterm has other powersaving related options, the most useful combination seems to be:

$ setterm -blank 0 -powersave off

Thus to permanently/automatically disable virtual console blanking on startup you can either:

  1. add the consoleblank=0 kernel parameter to the kernel command line (i.e. edit and update your boot loader configuration)

  2. add the setterm -blank 0 command to an rc-local or equivalent startup script

  3. add the setterm output to /etc/issue since /etc/issue is output on every virtual console:

    # setterm -blank 0 >> /etc/issue

Choose one alternative from the above.

maxschlepzig
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    **PS:** On a Ubuntu 11.10 system (Thinkpad X200) I noticed a bug where the console blanking by the kernel interferes with a running X11 session. That means that exactly 10 minutes after the last key press the X11 display blanks and you have to cycle to a virtual console to get the X11 screen back (very annoying during e.g. video playback). This is independent of DPMS/screensaver related settings under X11 (think `xset` etc.). Thus, disabling the virutal console blanking like described above is a quick workaround for affected systems. – maxschlepzig Feb 18 '12 at 21:13
  • hmmm. For some reason, I don't see `/sys/module/kernel/parameters/consoleblank` on my CentOS 5.x server. Could it be set under a different name? – Mike B Jul 15 '14 at 21:14
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    On RHEL 5 and 6, I found that putting `/bin/setterm -blank 0 -powerdown 0 -powersave off` in `/etc/rc.local` would work great. On RHEL 7, however it would fail. Adding `consoleblank=0` to te kernel parameters works on that platform. – David C. Nov 24 '15 at 17:07
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    Please note that you don't actually have to run `setterm` in a virtual console. You may as well redirect it to it: `setterm -blank 0 > /dev/tty1` works just fine. Or you may use `setterm -blank < /dev/tty1` to query the current value from tty1 or `setterm -blank force < /dev/tty1` to force blanking. – Alexander Amelkin Nov 09 '16 at 07:14
  • @AlexanderAmelkin - redirects to/from /dev/tty1 does not work in RHEL 7. Which distro were you using to do that? /dev/tty1 is indeed the local console, but neither that nor /dev/console seemed to do anything. – Paul Sep 26 '18 at 20:57
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    might be tty2 then, redhat erm... wizards chose to stick X onto tty1 now – Michael Shigorin Sep 27 '18 at 13:57
  • @Paul, I'm using Ubuntu 16.04. Try other tty numbers as Michael suggested earlier. – Alexander Amelkin Nov 07 '18 at 15:34
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    While I don’t have GRUB, I have a text file on a special partition, called `/boot/cmdline.txt`. I’ve added another parameter `consoleblank=0` to that file. It worked. Thanks a lot! – Soonts Aug 24 '22 at 20:52
16

Try using this:

setterm -blank
Uku Loskit
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  • I want this to be in effect automatically after boot, without logging in. There is nobody who will type the command ! Sometimes the screen blanks even during boot, for example if there is a SAN timeout. – markus_b Feb 25 '11 at 00:28
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    @markus_b: So add this command to an init script (something like `/etc/init/markus-console.conf` if you use Upstart, or `/etc/init.d/markus-console.sh` plus symlinks in `/etc/rd?.d` for SysVinit, I don't know the actual SuSE locations). – Gilles 'SO- stop being evil' Feb 25 '11 at 00:35
  • File that under "things you can't do with systemd". – mattdm Feb 25 '11 at 00:57
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    @mattdm, not true - `systemd` usually comes with a `rc-local` compatibility service - or you can easily add custom services ... – maxschlepzig Feb 18 '12 at 12:46
  • @maxschlepzig — when I wrote that, the developers were adamantly opposed to anything like rc.local. It's a year later now and that may have run into reality. – mattdm Feb 18 '12 at 13:55
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    @mattdm Why wouldn't you be able to just write a unit that runs that command? – remmy Mar 04 '13 at 12:39
  • Is there a busybox version of this command? – Atilla Filiz Jun 19 '14 at 09:13
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    TIP: Exit _tmux_ first, or this won't work. – Cody Hess Aug 05 '14 at 01:48
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    Here's [how to install this on a systemd-based distribution, using an rc-local service](http://superuser.com/a/462828/76876). – basic6 May 04 '15 at 15:59
15

According to : https://wiki.archlinux.org/index.php/Display_Power_Management_Signaling#DPMS_Interaction_in_a_console_with_setterm

Prevent screen from turning off (in console)

$ setterm -blank 0 -powerdown 0

Alternatively you can disable console blanking permanently using the following command:

# echo -ne "\033[9;0]" >> /etc/issue

Community
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Grzegorz Wierzowiecki
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15

The only permanent solution is to add consoleblank=0 to the kernel command-line. You can view the value (which defaults to 600 seconds) in: 

/sys/module/kernel/parameters/consoleblank

(note that the file is read-only). The only way to change the value of consoleblank is to reboot with the new kernel command-line option.

Mat
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amcnabb
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    The last sentence is wrong - you don't need to reboot to change the value of `consoleblank`. See my answer. – maxschlepzig Feb 18 '12 at 13:10
  • I have not found setterm -blank to work reliably. It sometimes seems to get reset after logout or switching to other virtual terminals. – amcnabb Mar 13 '12 at 18:10
  • To add this permanent setting with grub, edit /boot/grub/grub.conf and append consoleblank=0 to the lines starting with "kernel /boot/vmlinuz...". Then reboot. – Hoylen Jul 03 '14 at 04:00
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    "only" seems like a string word here... – notlesh Jan 15 '16 at 19:08
13

I've implemented and tested the following configuration, which works fine on sles10, my workhorse at the moment.

In

/etc/init.d/boot.local

add

setterm -blank

it looks like that is all it takes. Thanks for Uku Loskit and Gilles for the push in the right direction.

markus_b
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    I have edited your Answer mercilessly, so don't hesitate to rollback if you don't like it. Also, please Accept your answer because it's the actual solution. You should not Accept an Answer just because you are grateful it led you to the actual answer, if there is actually a better Answer. – tshepang Mar 01 '11 at 05:39
  • Sorry, like the original version better. – markus_b Mar 02 '11 at 19:07
  • I had to add the top voted answers -powersave off as the ipmi on my systemboard got stupid if it didn't have both parts of this. sadily enough it doesen't keep settings between uses and when these features kick in the window pops to the foreground and starts cycling the window through about 4 different sizes once every second or 2 making it near impossible to catch the window and manually resize it/kick the term out of power save :( – Kendrick Aug 10 '15 at 14:36
7

I was really buffled by this problem. All tricks above with using setterm and redirect from/to /dev/tty0 didn't worked from my ssh.

Then I realized a way to disable it:

TERM=linux setterm -blank 0 -powerdown 0  -powersave off >/dev/tty0 </dev/tty0

TERM=linux replaces default TERM (which is xterm-256color on my machine), and helps setterm to query proper parameters from tty0.

You can check result by

cat /sys/module/kernel/parameters/consoleblank

It should be 0. If it is 600, trick hasn't worked out.

George Shuklin
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6

If you only want to prevent screen blank out after user login, then just need to append setterm -powersave off -blank 0 to $HOME/.bash_profile of respective users.

jurijcz
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4

/usr/bin/setterm -powerdown 0 might help also

Michael Mrozek
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cnd
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2

For those of us running Ubuntu 20.04, simply append the following code to /etc/init.d/console-setup.sh

# Set screen blank time to 5 minutes (5)
log_action_begin_msg "Setting screen blank interval to 5 minutes"
/usr/bin/setterm -blank 5
log_action_end_msg $?
Graham Leach
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0

This one seems to do the trick:

echo 0 > /sys/class/graphics/fb0/blank

Found on Armadeus wiki.

James Risner
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user1707322
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