On Wed, Feb 18, 2009 at 2:47 PM, Ragnar Sundblad <ra...@csc.kth.se> wrote: > > I would very much appreciate some advice on this; > > For our file- and mail servers we have been using mirrored raid-5 > chassises, with disksuite and ufs. This has served us well, and the > el-cheapo raid-5 chassises have failed several times without any > downtime for our services. > > We are now looking for a modern but simple-to-handle-and-not-to-expensive > replacement for these servers. We still like the idea of having > raid-51 or similar security. By some reason that I haven't gotten > yet, zfs doesn't allow you to put "raids" upon each other, like > mirrors/stripes/parity raids on mirrors/stripes/parity raids, in a > single pool. Maybe it is just not necessary since you can make pools > out of pools. > > Now we could choose from: > 1) mirroring all disks with disk suite and build a raidz (or possibly > raidz2) on those > 2) creating two raidz[2] pools, creating a volume each on those, and > creating a third pool which is a zfs mirror of the volumes.
Why not just use zfs to mirror your hardware raid-5 chassis? You get the hardware to manage disk failures, but have data redundancy provided by zfs which is where you want it. If you want random I/O performance, raidz isn't a good choice. For most things, hardware raid ought to give you more IOPS. You mentioned mail and file serving, which isn't an obvious match for raidz (which works better for capacity and throughput). -- -Peter Tribble http://www.petertribble.co.uk/ - http://ptribble.blogspot.com/ _______________________________________________ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
