[ovirt-users] DR with oVirt: no data on OVF_STORE

[Luca 'remix_tj' Lorenzetto]

Hello,

i'm experimenting a DR architecture that involves block storage
replication from the storage side (EMC VNX 8000).

Our idea is to import the replicated data storage domain on another
datacenter, managed by another engine, with the option "Import Domain"
and then import all the vms contained.

The idea works, but we encountered an issue that we don't want to have
again: we imported an SD and *no* vm were listed in the tab "VM
Import". Disks were available, but no VM informations.

What we did:
 - on storage side: split the replica between the main disk in Site A
and the secondary disk Site B
 - on storage side: added the disk to the storage group of the
"recovery" cluster
 - from engine UI: Imported storage domain, confirming that i want to
activate even if seems to be attached to another DC
 - from engine UI: move out from maintenance the storage domain and
click on the "VM Import" tab of the new SD.

What happened: *no* vm were listed

To identify better what's happening, I've found here some indications
on how lvm for block storage works and I identified the command on how
to find and read the OVF_STORE.
Looking inside the OVF_STORE has shown why no vm were listed: it was
empty (no .ovf file listed with tar tvf)

So, without the possibility import vms, i did a rollback, detaching
the storage domain and re-establishing the replication between the
main site and the DR site.

Then, after a day of replications (secondary volume is  aligned every
30 minutes), i tried again and i've been able to import also vms
(OVF_STORE was populated).

So my question is: how to i force to have OVF_STORE to be aligned at
least as frequent as the replication? I want to have the VM disks
replicated to the remote site along with VM OVF informations.

Is possible to have OVF_STORE informations aligned when a VM is
created/edited or with a scheduled task? Is this so I/O expensive?

Thank you,


Luca



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Gottfried Wilhelm von Leibnitz, Filosofo e Matematico (1646-1716)

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Luca 'remix_tj' Lorenzetto, http://www.remixtj.net , <lorenzetto.luca at gmail.com>