On 18 May, 2007 - Dale Sears sent me these 1,5K bytes: > Tomas Ögren wrote: > >On 14 May, 2007 - Dale Sears sent me these 0,9K bytes: > > > >>I was wondering if this was a good setup for a 3320 single-bus, > >>single-host attached JBOD. There are 12 146G disks in this array: > >> > >>I used: > >> > >>zpool create pool1 \ > >>raidz2 c2t0d0 c2t1d0 c2t2d0 c2t3d0 c2t4d0 c2t5d0 c2t6d0 c2t8d0 c2t9d0 > >>c2t10 \ > >>spare c2t11d0 c2t12d0 [..] > >That raid set will give you the same random IO performance as a single > >disk. Sequential IO will be better than a single disk. > > > >For instance splitting it into two raidz2 disks without spares can > >survive any two disks within both groups (so 2 to 4 disks can fail > >without data loss).. Random IO performance will be twice the single > >raidz2/single disk. > > What would that command look like? Is this what you're saying?: > > zpool create pool1 \ > raidz2 c2t0d0 c2t1d0 c2t2d0 c2t3d0 c2t4d0 c2t5d0 \ > raidz2 c2t6d0 c2t8d0 c2t9d0 c2t10d0 c2t11d0 c2t12d0 > > Thanks!
Yep. Verify performance differences in your usage case between the two methods.. Its reliability against failures is a bit more of a gamble than a big one with 2HS.. If you're lucky, 4 disks can blow up at the same time without problems (vs 2 in your version).. If you're unlucky, 2 disks from the same set blows up and then another one before you had the chance to replace them with cold spare(s).. If first 2 then another one during a weekend or so.. A hot spare could have saved you then.. If you have a cold spare laying around and replacing as soon as one break, this shouldn't be a problem.. but it can make a difference, it's up to you to decide (or attach a single additional hotspare outside the 3320). /Tomas -- Tomas Ögren, [EMAIL PROTECTED], http://www.acc.umu.se/~stric/ |- Student at Computing Science, University of Umeå `- Sysadmin at {cs,acc}.umu.se _______________________________________________ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
