On Wed, 14 Jan 2009, Eric Sproul wrote: > I'm looking for a recommendation for the vdev layout of a storage server that > has 6 1TB SAS drives. I need 4TB of usable space, which I can get one of 2 > ways: 1 raidz2 vdev or 2 raidz1 vdevs. Reading best practices, blogs and this > list, I understand that having more top-level vdevs is good for IOPS, but I > wonder how that balances against the likelihood of 2 disk failures occurring > in > the same vdev in the second case, which would cause total data loss. The > first > case would permit *any* 2 disks to fail, which would reduce the overall risk.
If it was me, I would go for the raidz2 solution. It seems wasteful to use raidz with only three drives. If you ever add another set of drives to the system, then it will feel downright foolish. Yes, there will be more available IOPS with two vdevs. If you really want IOPS then use mirrors instead, and settle for only 3TB of usable storage. Bob ====================================== Bob Friesenhahn [email protected], http://www.simplesystems.org/users/bfriesen/ GraphicsMagick Maintainer, http://www.GraphicsMagick.org/ _______________________________________________ storage-discuss mailing list [email protected] http://mail.opensolaris.org/mailman/listinfo/storage-discuss
