For Linux, I've been able to achieve what I want with DRBD but I'm hoping I can find a similar solution on Solaris so that I can leverage ZFS. It seems that solution is Sun Availability Suite (AVS)?
AVS is like DRBD, but only to a point. If the drives on your primary fail, the primary will start reading from the drives on the secondary.
However, a critical difference is that after the primary fails and the secondary takes over, you won't have a mirror until you bring the primary completely back online as the primary. You can't make it the secondary temporarily. DRBD can trivially reverse the roles on the fly, so you can run the secondary as a primary and primary as the secondary and the mirroring works in reverse automatically.
One of the major concerns I have is what happens when the primary storage server fails. Will the secondary take over automatically (using some sort of heartbeat mechanism)? Once the secondary node takes over, can it fail-back to the primary node once the primary node is back?
When the server fails, your users would lose access because AVS deals only with storage. It has no "heartbeat" functionality for the server itself. This is similar to DRBD. Ordinarily, you run DRBD and Linux-HA (Heartbeat). Unfortunately, there are no simple, easy to implement heartbeat mechanisms for Solaris.
My concern is that AVS is not able to repair the primary node after it has failed, as per the conversation in this forum:
The secondary can repair the primary, but the primary must be running actively as the primary. That is, unlike DRBD where the roles of primary and secondary are reversed, they are not under AVS.
Is AVS even the right solution here, or should I be looking at some other technology?
The simplest way to achieve DRBD-like functionality is to use iSCSI. You create a zvol and iSCSI target on each server and then set up multipathed initiators. Then create a mirrored pool in ZFS out of the zvols. With some kind of heartbeat mechanism in place, you can move the (degraded) mirrored pool to the secondary.
-- Maurice Volaski, maurice.vola...@einstein.yu.edu Computing Support, Rose F. Kennedy Center Albert Einstein College of Medicine of Yeshiva University _______________________________________________ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
