libvirt users - Dec 2010 - Deploying libvirt with live migration

I have two physical servers: Virt1 and Virt2. I'm setting up live 
migration with CentOS 5.5 between the two. I've done this by NFS 
mounting /etc/libvirt and /var/lib/libvirt/images on both servers. This 
is working well for me except for one thing.

I see the same list of VMs on each server (as expected), but each server 
(Virt1 and Virt2) are able to start the same VM at the same time. This 
obviously causes IP conflicts and thrashes the disk image. Is there a 
way to tell my VM "cluster" that a VM is only allowed to be opened on 
one host at a time?

-- 
Scott Baker - Canby Telcom
System Administrator - RHCE - 503.266.8253

I've run into the same scenario... I've often wondered if it
wouldn't make
sense to have a lock file or some other notification in place to let both 
hosts know who currently has "ownership" of the VM.

David.

On Mon, 13 Dec 2010, Scott Baker wrote:
> I have two physical servers: Virt1 and Virt2. I'm setting up live
migration
> with CentOS 5.5 between the two. I've done this by NFS mounting
/etc/libvirt
> and /var/lib/libvirt/images on both servers. This is working well for me 
> except for one thing.
>
> I see the same list of VMs on each server (as expected), but each server 
> (Virt1 and Virt2) are able to start the same VM at the same time. This 
> obviously causes IP conflicts and thrashes the disk image. Is there a way
to
> tell my VM "cluster" that a VM is only allowed to be opened on
one host at a
> time?
>
> -- 
> Scott Baker - Canby Telcom
> System Administrator - RHCE - 503.266.8253
>
> _______________________________________________
> libvirt-users mailing list
> libvirt-users at redhat.com
> https://www.redhat.com/mailman/listinfo/libvirt-users
>

2010/12/13 Scott Baker <bakers at canbytel.com>:
> I have two physical servers: Virt1 and Virt2. I'm setting up live
migration
> with CentOS 5.5 between the two. I've done this by NFS mounting
/etc/libvirt
> and /var/lib/libvirt/images on both servers. This is working well for me
> except for one thing.
>
> I see the same list of VMs on each server (as expected), but each server
> (Virt1 and Virt2) are able to start the same VM at the same time. This
> obviously causes IP conflicts and thrashes the disk image. Is there a way
to
> tell my VM "cluster" that a VM is only allowed to be opened on
one host at a
> time?
>
Well don't share /etc/libvirt, there is no need to.

Just have the domain config on the host that currently executes the
domain and tell libvirt to migrate the persistent domain condif along
with the domain:

virsh migrate --persistent --undefinesource vm1 qemu://virt2/system

Matthias