> "The recommended number of disks per group is between 3 and 9. If you have > more disks, use multiple groups." > > Odd that the Sun Unified Storage 7000 products do not allow you to control > this, it appears to put all the hdd's into one group. At least on the 7110 > we are evaluating there is no control to allow multiple groups/different > raid types.
Our experience has shown that that initial guess of 3-9 per parity device was surprisingly narrow. We see similar performance out to much wider stripes which, of course, offer the user more usable capacity. We don't allow you to manually set the RAID stripe widths on the 7000 series boxes because frankly the stripe width is an implementation detail. If you want the best performance, choose mirroring; capacity, double-parity RAID; for something in the middle, we offer 3+1 single-parity RAID. Other than that you're micro-optimizing for gains that would hardly be measurable given the architecture of the Hybrid Storage Pool. Recall that unlike other products in the same space, we get our IOPS from flash rather than from a bazillion spindles spinning at 15,000 RPM. Adam -- Adam Leventhal, Fishworks http://blogs.sun.com/ahl _______________________________________________ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
