[sheepdog] [PATCH] collie/farm: save vmstate objects during cluster-wide snapshot

[MORITA Kazutaka]

At Mon, 24 Jun 2013 23:37:44 +0800,
Liu Yuan wrote:
> 
> On Mon, Jun 24, 2013 at 10:16:59PM +0800, Kai Zhang wrote:
> > 
> > On Jun 24, 2013, at 8:18 PM, Liu Yuan <namei.unix at gmail.com> wrote:
> > 
> > > On 06/24/2013 02:04 PM, Kai Zhang wrote:
> > >> Without this patch, qemu's 'loadvm' command will fail after
> > >> loading cluster-wide snapshot to a new cluster.
> > > 
> > > Seems that this patch isn't well tested.
> > > 
> > > #before the save
> > > yliu at yliu-K55VM:~/sheepdog$ md5sum store/0/obj/407c2b2500000000
> > > 2657263030ea9bd6f54b273ad377a1eb  store/0/obj/407c2b2500000000
> > > #after load
> > > yliu at yliu-K55VM:~/sheepdog$ md5sum store/0/obj/407c2b2500000000
> > > 1d42bb5c3a6b47c2fc45019228f94a17  store/0/obj/407c2b2500000000
> > > 
> > > And
> > > yliu at yliu-K55VM:~/sheepdog$ ../qemu/x86_64-softmmu/qemu-system-x86_64 --enable-kvm -m 1024 -hda sheepdog:test -loadvm 1
> > > qemu-system-x86_64: Error -22 while loading VM state
> > > 
> > > The loadvm failed.
> > > 
> > 
> > I failed to reproduce this error in my environment.
> > And the patch can work fine on my ubuntu server.
> > Could you find some hints from the sheep.log?
> 
> I tried it on my 12.04 destop several times, and it stills fails
> 
> yliu at yliu-K55VM:~/sheepdog$ collie/collie cluster snapshot save tag snapshot/
> yliu at yliu-K55VM:~/sheepdog$ sha1sum store/0/obj/407c2b2500000000 
> 363a4f0ca8d7e3ce9e10bd7b438912006f495503  store/0/obj/407c2b2500000000
> yliu at yliu-K55VM:~/sheepdog$ sha1sum store/0/obj/407c2b2500000000 
> 363a4f0ca8d7e3ce9e10bd7b438912006f495503  store/0/obj/407c2b2500000000
> yliu at yliu-K55VM:~/sheepdog$ collie/collie cluster snapshot list  snapshot/
> Index		Tag		Snapshot Time
> 1		tag		Mon Jun 24 23:30:57 2013
> yliu at yliu-K55VM:~/sheepdog$ collie/collie cluster snapshot load tag snapshot/
>     __
>    ()'`;
>    /\|`
>   /  |   Caution! The cluster is not empty.
> (/_)_|_  Are you sure you want to continue? [yes/no]: yes
> using backend plain store
> yliu at yliu-K55VM:~/sheepdog$ sha1sum store/0/obj/407c2b2500000000 
> e52614830cf50c418d99128eb899aede6f22b9c4  store/0/obj/407c2b2500000000
> yliu at yliu-K55VM:~/sheepdog$ ../qemu/x86_64-softmmu/qemu-system-x86_64 --enable-kvm -m 1024 -hda sheepdog:test -loadvm 1
> qemu-system-x86_64: Error -22 while loading VM state

I'm trying this patch too but hitting another problem.  After loadvm,
qemu prints a lot of error message as follows:

 qemu-system-x86_64: failed to save vmstate Resource temporarily unavailable
 qemu-system-x86_64: No object found

This happens even when I don't use collie cluster snapshot, and I
guess there is a bug in the live snapshot codes.  This patch itself
looks working correctly.

Thanks,

Kazutaka