On Wed, Mar 14, 2007 at 11:26:51PM +0100, Rhialto wrote:
> On Fri 09 Mar 2007 at 15:57:50 -0500, Perry E. Metzger wrote:
> > As Manuel points out, it is actually not that simple. Ideally, you
> > want to write out to the file system, and that means you can induce
> > lots of state in the kernel, and thus you risk writing out an
> > inconsistent set of data structures. Even if you are only writing out
> > to the swap partition, it is still a bit of work to make sure that you
> > don't end up writing out something that will crash when read back in.
> 
> It seems it's a lot like migrating a VM from one real machine to
> another. Isn't Xen supposed to support that? Or did that never get past
> the "interesting paper" stage?

It does. But it's not the guest that is doing the work; the dom0
is. It's a lot like APM's suspend/resume to disk, where it's the
BIOS which is dumping/restoring the RAM content. Here we're talking about
the OS itself dumping/restoring its states, which makes it at lot more
difficult.

-- 
Manuel Bouyer <bouyer@antioche.eu.org>
     NetBSD: 26 ans d'experience feront toujours la difference
--