Re: [ovirt-users] Protecting the storage of the self hosted engine

On 05.11.2014 15:30, wodel youchi wrote: Hello and welcome! IHMO reliable hardware and contingency plans. First we need to define 'weak link'. IMOH this can be Network and / or storage hardware like controllers and spindles (SSDs). As the later tends to be reliable I think your mean indeed the data link layer as 'weak link'? Gluster can be the same weak link for instance, as it needs a network layer. If you use iSCSI together with some storage appliance maybe with redundant controllers, this setup is quite reliable and engine storage is protected if you use iSCSI Multipath (and the paths are indeed separate hardware switches). You could call NFS a weak link; but even there are quite reliable setups available witch support fail over, replicated storage and IPMP. I have to warn you at this point. This setup seems quite tempting; even using localhost addresses with gluster's build in NFS. This was tried before (myself included) but it is far from stable. You would at least need repica 3 gluster volumes to avoid split brains. These seem to happen quite often. I include Martin here, we talked about this at the ovirt workshop in Düsseldorf; maybe he can provide a better explanation. AFAIK gluster will be supported as engine storage in the future; but this is not the case right now. Of course, you are welcome to try! That said, and because you are new to ovirt, the main thing you need to protect is not the engine storage, but your production data domains. The VMs will run fine and continue to run with the engine down or not available. In case of a real disaster, you will be able to import these storage domains along with their VMs to a new engine. For me, I tend to have my engine backed up using engine-backup [1] and put the result to a different storage. From that data you can recreate the whole engine. HTH [1] http://www.ovirt.org/Ovirt-engine-backup -- Daniel Helgenberger m box bewegtbild GmbH P: +49/30/2408781-22 F: +49/30/2408781-10 ACKERSTR. 19 D-10115 BERLIN www.m-box.de www.monkeymen.tv Geschäftsführer: Martin Retschitzegger / Michaela Göllner Handeslregister: Amtsgericht Charlottenburg / HRB 112767