Re: Hibernating To Swap Considered Harmful

Rafael J. Wysocki
2007-07-14T09:40:52Z

On Saturday, 14 July 2007 02:45, Joseph Fannin wrote:
> On Fri, Jul 13, 2007 at 11:30:50AM +0200, Rafael J. Wysocki wrote:
> > On Friday, 13 July 2007 07:42, Joseph Fannin wrote:
> > > On Thu, Jul 12, 2007 at 08:06:43PM -0700, david@lang.hm wrote:
> > > > On Thu, 12 Jul 2007, Rafael J. Wysocki wrote:
> > >
> > > > > Plus we need to figure out how to avoid corrupting filesystems and
> > > > > swap in use by the "old" kernel and its processes (hint: a separate
> > > > > "hibernation partition" is a no-go).
> > > >
> > > > I thought the existing hibernation wrote to the swap partition as it's
> > > > dedicated space?
> > > >
> > > > I didn't know that anyone was suggesting writing the hibernation image to
> > > > a filesystem that the kernel was activly accessing.
> > >
> > > I'm suggesting a dedicated, preallocated hibernation *file*, right
> > > now. There's no way around it, if hibernation is to be reliable --
> > > otherwise hibernation can fail if the system has used enough of its
> > > swap space, so that there isn't enough room to write the hibernate
> > > image.
> > >
> > > Even if it's desirable to allow hibernation to fail if the system is
> > > too deep into swap, it's a moot point.
> >
> > If you're afraid of that, use a dedicated swap file.
>
> I don't understand what you mean. A dedicated swap file for what?

Sorry, I should have been more precise.

For hibernation (ie. a swap file that you activate right befor the
hibernation).

Also tuxonice (formerly known as suspend2) allows you to use regular files
hibernation.

Greetings,
Rafael

--
"Premature optimization is the root of all evil." - Donald Knuth