[Lguest] lguest stop/restart and guest (live?) migration

[Rusty Russell]

On Mon, 8 Jun 2009 03:01:29 am Matias Zabaljauregui wrote:
> Hi, everybody seem to be working this weekend...
>
> > I'd start with save and restore.  All we really need is a method of
> > setting and restoring guest state, which should then also be used to boot
> > the guest (with sanity checks).
> >
> > Something like:
> > LHREQ_GETREGS /* + addr */
> > LHREQ_SETREGS /* + addr */
>
> ok, I've started to write some code.
>
> Still can't imagine how to save guest memory contents
> in some efficient way.
>
> Am I supposed to write every "guest frame" down to a file ?
> (i.e. if my guest's memory is 1GB , the guest-memory-contents file will
> be 1 GB ?

That's the standard way.  Instead of mapping /dev/zero, map some real file.  
Then it "just works".

A fancier method would be to do compression, but disk space is cheap.

Cheers,
Rusty.