Hello all, A couple of months ago I wrote up some ideas about clustered ZFS with shared storage, but the idea was generally disregarded as not something to be done in near-term due to technological difficultes.
Recently I stumbled upon a Nexenta+Supermicro report [1] about cluster-in-a-box with shared storage boasting an "active-active cluster" with "transparent failover". Now, I am not certain how these two phrases fit in the same sentence, and maybe it is some marketing-people mixup, but I have a couple of options: 1) The shared storage (all 16 disks are accessible to both motherboards) is split into two ZFS pools, each mounted by one node normally. If a node fails, another imports the pool and continues serving it. 2) All disks are aggregated into one pool, and one node serves it while another is in hot standby. Ideas (1) and (2) may possibly contradict the claim that the failover is seamless and transparent to clients. A pool import usually takes some time, maybe long if fixups are needed; and TCP sessions are likely to get broken. Still, maybe the clusterware solves this... 3) Nexenta did implement a shared ZFS pool with both nodes accessing all of the data instantly and cleanly. Can this be true? ;) If this is not a deeply-kept trade secret, can the Nexenta people elaborate in technical terms how this cluster works? [1] http://www.nexenta.com/corp/sbb?gclid=CIzBg-aEqKwCFUK9zAodCSscsA Thanks, //Jim Klimov _______________________________________________ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
