----- Am 15. Okt 2018 um 21:47 schrieb Peter Crowther peter.crowther@melandra.com:
Pacemaker always knows where its resources are running. Query it, stop the domain, then use the queried location as the host to which to issue the snapshot?
But can i be sure that the resource starts on the node it was running before ? IMHO no. What is if i start the snapshot on node A but the resource starts afterwards on node B ? Then libvirt on node B does not know it should perform a snapshot.
On Mon, 15 Oct 2018, 20:36 Lentes, Bernd, < [ mailto:bernd.lentes@helmholtz-muenchen.de | bernd.lentes@helmholtz-muenchen.de ] > wrote:
Hi,
i have a two node cluster with virtual guests as resources. I'd like to snapshot the guests once in the night and thought i had a procedure. But i realize that things in a cluster are a bit more complicated than expected :-))
I will shutdown the guests to have a clean snapshot. I can shutdown the guests via pacemaker. But then arises the first problem:
When i issue a "virsh snapshot-create-as" libvirt needs the domain name as a parameter. but libvirt does not know the domains any longer. When the guests are shutdown a "virsh list --all" on both nodes does not show any domain.
A look in the respective resource agent VirtualDomain explains why: The domain is started with virsh create:
"# The 'create' command guarantees that the domain will be # undefined on shutdown, ...
OK: Now i could of course define all domains with a virsh define.
But then i have immediately the next problem. Now i'd create the snapshots with "virsh snapshot-create-as" and starts the domains afterwards via cluster. But let's assume i issue that on node 1 and some guests are started afterwards via pacemaker on node 2. I can't predict on which node the guests are starting.
Then i don't get a snapshot, right ?
What to do ?
Bernd
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