Disable Screen Blanking on Text Console – Prevent Terminal Screen Blanking

consolelinuxsuseterminal

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.

Best Answer

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 consoleblank=0 to the kernel parameters (edit grub 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.

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