[ovirt-devel] DRBD Integration with oVirt

[Hayley Swimelar]

On 06/06/2016 10:38 PM, Barak Korren wrote:
>>> But what sort of user experience and system architecture is intended?
>>> Is configuration of volumes planned to be done directly from the oVirt
>>> UI?
>>
>> Once a DRBD Manage storage cluster is set up, oVirt would handle the
>> management of DRBD volumes.
>
> So does this mean there would be some kind of a "DRBD" cluster, like
> the "Gluseter cluster" oVirt has right now?
>

Correct, there would be a cluster made up of nodes that contribute to 
the storage pool that is made available through DRBD. Host nodes would 
have to be in this cluster as well, but they would not necessarily have 
to have a large pool of their own storage.

>>> As far as using DRBD for backing oVirt VMs, this seems to already be
>>> working. The oVirt CI system (which runs on top of oVirt) had been
>>> using a DRBD-backed NFS storage for years...
>>>
>>
>> The most recent release of DRBD contains new features that allow it to
>> integrate more directly with virtualization/cloud platforms. So VMs could
>> have DRBD-backed storage without additional overhead from NFS.
>
> Could you elaborate a little on how this works? Would this means the
> block devices would be configured on the hypervisors themselves? Is
> this intended to be some kind of a hyper-converged architecture?
>
>

The DRBD devices will appear on the hypervisors 
(/dev/drbd100/dev/drbd101, etc.) but writes and reads on those devices 
will be completed over the DRBD replication link. Unless that node has 
that volume locally, in which case it would use it's local storage like 
a standard DRBD device.

-- 
Hayley Swimelar
LINBIT | Keeping the Digital World Running
DRBD — Corosync — Pacemaker
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