Disable suspend and hibernation

X11 wants to blank the screen out of the box. To prevent, try putting

xset dpms 0 0 0 && xset s noblank  && xset s off

in .bashrc

For systems which should never attempt any type of suspension, these targets can be disabled at the systemd level with the following:

sudo systemctl mask sleep.target suspend.target hibernate.target hybrid-sleep.target

To re-enable hibernate and suspend use the following command:

sudo systemctl unmask sleep.target suspend.target hibernate.target hybrid-sleep.target

A modern alternative approach for disabling suspend and hibernation is to create /etc/systemd/sleep.conf.d/nosuspend.conf as

[Sleep]
AllowSuspend=no
AllowHibernation=no
AllowSuspendThenHibernate=no
AllowHybridSleep=no

The above technique works on Debian 10 Buster and newer. See systemd-sleep.conf(5) for details.

If you just want to prevent suspending when the lid is closed you can set the following options in /etc/systemd/logind.conf:

[Login]
HandleLidSwitch=ignore
HandleLidSwitchDocked=ignore

Then run systemctl restart systemd-logind.service or reboot.

More information is available in the manpage: man logind.conf

PIHI