What is the shell command to let a Linux box go sleep?

Question

I'm writing a shell script to check the I/O activity of a Linux box and if the server is quiet for a certain long time, the script should let the server go to sleep. But, after some Google searching, I didn't find a answer yet. Is there a shell script command to put a Linux box to sleep?

Answer 1

Using the handy pm-utils package, you can issue commands to suspend and hibernate without echo'ing values to the system. For example:

$ pm-suspend
$ pm-hibernate

Answer 2

To answer your question simply, echo -n mem > /sys/power/state or apm -z should bring your linux system to sleep, depending on whether it uses ACPI or APM. However not all is necessarily happy, and you might want to take a look at this article about how to restore the video memory and sleep a system properly from a shell script.

Answer 3

If your setup supports hibernation you can use the sys interface

echo -n mem >/sys/power/state

to suspend to ram and

echo -n disk >/sys/power/state

to suspend to disk.

Remind that your kernel and hardware have to support it to use it.