Bob,
On 01/31/2012 09:54 PM, Bob Friesenhahn wrote: > On Tue, 31 Jan 2012, Thomas Nau wrote: > >> Dear all >> We have two JBODs with 20 or 21 drives available per JBOD hooked up >> to a server. We are considering the following setups: >> >> RAIDZ2 made of 4 drives >> RAIDZ2 made of 6 drives >> >> The first option "wastes" more disk space but can survive a JBOD failure >> whereas the second is more space effective but the system goes down when >> a JBOD goes down. Each of the JBOD comes with dual controllers, redundant >> fans and power supplies so do I need to be paranoid and use option #1? >> Of course it also gives us more IOPs but high end logging devices should take >> care of that > > I think that the answer depends on the impact to your business if data is > temporarily not available. If your business can not > survive data being temporarily not available (for hours or even a week) then > the more conserative approach may be warranted. We are talking about home directories at a university so some downtime is ok but fore sure now hours or even days. We do regular backups plus snapshot send-receive to a remote location. The main thing I was wondering about is if it's better to have a downtime if a JBOD fails (rare I assume) or to keep going without any redundancy left. > If you have a service contract which assures that a service tech will show up > quickly with replacement hardware in hand, then > this may also influence the decision which should be made. The replacement hardware is kind of on-site as we use it for the disaster recovery on the remote location > Another consideration is that since these JBODs connect to a server, the data > will also be unavailable when the server is down. > The server being down may in fact be a more significant factor than a JBOD > being down. I skipped that, sorry. Of course all JOBDs are connected through multiple SAS HBAs to two servers so server failure is easy to handle Thanks for the thoughts Thomas _______________________________________________ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
