Would ZFS and gmirror work well together in a two-node failover cluster?

[Maurice Volaski]

>Which type of connection do you intend to use for the shared storage
>JBOD? SAN or direct attached SCSI? Don't forget to change the SCSI

On each server, there would be a SATA JBOD attached internally with a 
3Ware or Areca card.

>Which means your two node cluster won't be active/active. You'll have
>an active node and a failover node. That may be alright or it may not.

Right, there would be a primary server,which contains the mounted 
drives and the failover, where only the ggated and gmirror see the 
drives (until a primary failure occurs and presumably something like 
heartbeat would then mount these drives and take over as the new 
primary).

>Now if we come back to the problem at hand, mainly using zfs under
>gmirror. I've never heard of anyone using this. It does sound a bit
>strange to me since both zfs and gmirror will do mirroring. I would

gmirror would be doing mirroring, but ZFS would be doing RAIDZ2. So 
altogether it's RAIDZ2 + RAID 1. Under Linux, such an arrangement is 
fairly easy to do with an ordinary filesystem and the local RAID 
would be handled at another layer, either in hardware or in software 
with md. DRBD would do the mirroring.
-- 

Maurice Volaski, mvolaski at aecom.yu.edu
Computing Support, Rose F. Kennedy Center
Albert Einstein College of Medicine of Yeshiva University