Re: [Qemu-devel] Re: [PATCH 0/3] Live migration without shared storage (improved version)

[Liran Schour]

address@hidden wrote on 11/09/2009
14:25:29:

> address@hidden wrote:
> > This series adds support for live migration without shared storage,
means
> > copy the storage while migrating. It was tested with KVM. Supports 2
ways
> > to replicate the storage during migration:
> >  1. Complete copy of storage to destination
> >  2. Assuming the storage is cow based, copy only the allocated
> >     data, time of the migration will be linear with the amount of
allocated
> >     data (user responsibility to verify that the same backend file
reside
> >     on src and destination).
> >
> > Live migration will work as follows:
> > (qemu) migrate -d tcp:0:4444 # for ordinary live migration
> > (qemu) migrate -d blk tcp:0:4444 # for live migration with
> complete storage copy
> > (qemu) migrate -d blk inc tcp:0:4444 # for live migration with
> incremental storage copy, storage is cow based.
> >
> > The patches are against
git://git.kernel.org/pub/scm/virt/kvm/qemu-kvm.git
> > kvm-87
>
> As you are posting to qemu-devel, you should base your work on top of
> qemu.git master and make sure that it still works as intended. Upstream
> has KVM support (that is normally even usable), so testing won't take
> much longer than with qemu-kvm.
>
I will post a patch based on qemu.git.

> Nice feature by the way! Are you (also) using it to generate backups of
> a VM without stopping it (for a noticeably long time)? That's what we
> have in mind ATM.
>
Right now I am not using it for different scenario accept live migration.
But it
can be done easily.

- Liran