Why don’t you update o renew this blog post at nowadays maybe giving it this title

“DRBD 8.3.8.1 brings full live migration for XenServer 5.6 on DRBD”

I also noticed that XenMotion is available on XenServer free edition (and I’ll do my testings, at least, as soon I well understand how to export and import VMs’s metadata the correct way).

Thank you

R.

yes of course you can utilize load balancing/load sharing in this configuration mode. Please drop us an email at sales@linbit.com if interested in obtaining details on how to set this up.
The same goes for backup; there are several options. LVM snapshots being one of them, obviously.

In drbd active/active mode configuration, is it possible to use drbd to grant either HA either manual load balancing and computing load sharing assigning different active VMs to different physical hosts in the cluster?

What could be a good solution for backup? It is, I was thinking to lvm over drbd snapshotting, but you stated that for this to work is needed that the overlying file system is freezed and that such condition is hard to reach. But is it a filesystem needed? It is not possible to use logical volumes only containing VM images? And if it is possible, are there yet problem in lvm snapshot backups?

yes you can use LVM snapshots with DRBD, however it’s advisable to make sure that the file system is “frozen” at the time the snapshot is created. That’s not too easily feasible when using DRBD as Xen VBDs. YMMV.

this does not require GFS. Nor OCFS2. Indeed, the point is to avoid the need for a clustering file system.

The helper script makes your VBDs Primary on domU creation, and Secondary on domU destruction. The allow-to-primaries option is there to allow live migration, since Xen assumes to have write access to the backing both the source and the destination host at the time of migration. If you’re not using live migration, you can do fine without allow-two-primaries.