On Tue, Apr 26, 2011 at 1:55 AM, ENJOLRAS Fabien <enjolrasfab...@voila.fr> wrote: > I would like to build a high density storage server which will be evolutive. > Here is the hardware I have available: > -Norco RPC-4224 chassis (rackable 4U with x24 3.5 SATA disk hotswap backplane) > -Tyan Tempest i5000VF motherboard with dual 3 Ghz Xeon and 8GB ECC DDR2
You should verify that the motherboard and devices are supported. If it doesn't use Intel NICs onboard, you may want to consider getting some. Consider adding more memory. > My question was, how can I grow a raidz3 array with more drives? What is the > most secure and reliable method without the need to backup all the data > already stored? You can't grow a raidz vdev, but you can add more vdevs to the pool. > I've thought of creating a first raidz3 vdev with 6 drives, the adding up to > 4 6-drive raidz3 vdevs. But this way I lose a lot of storage on the base 48TB? A 6-drive vdev is sub-optimal. You'd be better off going with (2^n + p) drives, where p is the amount used for parity. For raidz3, that's 5, 7, 11, 19 and for raidz2, it's 4, 6, 10, 18. The sweet spot is the middle of the range. If you want to optimize for space vs. performance, three 7-drive vdevs will give you 24TB, or two 11-drive vdevs will yield 32TB. Both configurations leave bays available for spares. If you want slightly higher performance, you can use more vdevs. 4 x 6-drive raidz2 vdevs will give you 32TB of space and should have roughly twice the random iops performance of the 2x11 configuration above. For much higher perfomance, 12x mirrored vdevs will give you 24TB and roughly 4 times the random iops of the 3x7 configuration. It's also easiest to grow a zpool that's made of mirrors because you can simply add two more drives rather than enough to make up an additional vdev. -B -- Brandon High : bh...@freaks.com _______________________________________________ opensolaris-discuss mailing list opensolaris-discuss@opensolaris.org
