Re: [libvirt-users] RBD images locking
De : Daniel P. Berrange [mailto:berrange@redhat.com]
Envoyé : vendredi 8 novembre 2013 06:32
À : Eric Blake
Cc : NEVEU Stephane; libvirt-users(a)redhat.com
Objet : Re: [libvirt-users] RBD images locking
On Thu, Nov 07, 2013 at 09:08:58AM -0700, Eric Blake wrote:
On 11/07/2013 09:04 AM, NEVEU Stephane wrote:
> Eric,
[please don't top-post on technical lists]
>
> Well, in case where several servers may start the same virtual machines after a
reboot for exemple.
> http://lists.ceph.com/pipermail/ceph-users-ceph.com/2013-August/0038
> 87.html
Isn't the existing virtlockd support already sufficient for this? If
not, what is preventing the virtlock framework from interacting with
rbd disks?
Nothing really. The current impl only deals with disks with type=file
or type=block, ignoring type=network. We could extend it to cope with the latter though -
either using a URI to uniquely identify the >network storage, or better yet using some
unique volume ID if available.
Yes it might be useful when not using an orchestrator. Can't we use the
"block_name_prefix" of a volume to do so ? It seems to be unique and to be the
entry point to identify an image (via objects) across a pool :
rbd -p mypool info myvm
rbd image 'myvm'
Size 10240 MB in 2560 objects
Order 22 (4096 kB objects)
block_name_prefix: rb.0.11a6.238e1f29
format: 1
rados -p mypool ls | grep ^rb.0.11a6.238e1f29 | wc -l
630 objects