Messages in this thread | | | Date | Mon, 14 Jul 2008 07:43:52 +0200 | From | Pavel Machek <> | Subject | Re: hibernate/suspend-to-disk: to turn power or not? |
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On Sun 2008-07-13 18:26:36, David Fries wrote: > On Thu, Jan 31, 2008 at 03:40:30PM +0100, Pavel Machek wrote: > > > Back to the original question and a proposed solution. > > > > > > I'm looking at the uswsusp source (while the kernel compiles), > > > and have a question here. Is it possible to call some external > > > application (typically a shell script) to do the final work after > > > when the image has been written? I mean in principle - I > > > understand there are some limitations here, but I don't know > > > which exactly. > > > > No, you can't exec() anything. That would write mtime back to disk and > > cause badness. > > SysRq-U remounts the disks readonly. Why not make the disks readonly > once the kernel state is in swap, why not let any program run and give > an error to writes?
IIRC sysrq-U does not contain all the locking that's neccessary to make it completely safe. OTOH, it tends to work...
> I know, long dead thread, but I too would like to tell the UPS to turn > off once the system state is resting safely in swap. Currently my > modified apcupsd scripts tell the UPS to turn off, then tells the > kernel to hibernate, and hopes the kernel finishes in time. I would > much rather do things the other way, but `echo disk > /sys/power/disk` > doesn't return until power is back on if everything goes well.
If you use s2disk, you can execute C code at the point you want...
Pavel -- (english) http://www.livejournal.com/~pavelmachek (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html
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