Kill the power faster than poweroff?
asabigue at fing.edu.uy
Thu Sep 11 06:19:38 EDT 2003
halt -p -f
I tried it and it takes 3s instead of 20 or more :-)
From the man page:
Under older sysvinit releases , reboot and halt should never be
called directly. From release 2.74 on halt and reboot
invoke shutdown(8) if the system is not in runlevel 0 or 6. This
means that if halt or reboot cannot find out the cur
rent runlevel (for example, when /var/run/utmp hasn't been
initialized correctly) shutdown will be called, which might
not be what you want. Use the -f flag if you want to do a hard
halt or reboot.
It seems that it performs the sync call BEFORE killing the system but I
think you should be careful.
David Mathog wrote:
>Is there a faster way to shutdown a system and kill
>the power than "poweroff"? This is for use in
>emergency overheating conditions, where something
>that's effectively the equivalent of:
> % sync
> [turn off the power supply]
>lm_sensors and mondo are running on our Athlon 2200MP
>cluster and I'm concerned that in the event of a
>catastrophic failure of the cooling system the CPUs
>might overheat before the poweroff sequence completes.
>Not necessarily flame out immediately, but at least
>get hot enough so that they no longer run correctly,
>then poweroff wouldn't be able to complete, and then
>it's roasted CPU time.
>Tyan 2466 motherboards.
>This is only for emergency overheating, poweroff is
>fine for a normal shutdown.
>mathog at caltech.edu
>Manager, Sequence Analysis Facility, Biology Division, Caltech
>Beowulf mailing list, Beowulf at beowulf.org
>To change your subscription (digest mode or unsubscribe) visit http://www.beowulf.org/mailman/listinfo/beowulf
Beowulf mailing list, Beowulf at beowulf.org
To change your subscription (digest mode or unsubscribe) visit http://www.beowulf.org/mailman/listinfo/beowulf
More information about the Beowulf