You dont need a hw raid card with ZFS, instead ZFS prefers to work alone. It is the best solution to ditch a hw raid card.
I strongly advice you to use raidz2 (raid-6). Because if you use raidz1 (raid-5) and a drive fails, you have to swap that disc and repair your zfs raid. That will cause lots of stress on your other drives. If you try to repair a 1TB drive, it can take 6h. If you try to repair a >4TB it can take a week. During that time, if another drive fails, your data is lost. It takes long time to repair a raid, because the transfer speeds are slow compared to storage capacity. If you have lots of discs, it is adviced to create several groups (vdev) and make one large zpool of the groups. Each group should be a raidz1 or raidz2. I prefer raidz2. You can add a new group later if you wish. But you can not remove a group. But, it is as easy to just swap the drives to larger ones. Say you have 1TB drives in your zpool, then you can swap one drive at a time to 2TB drives. Then your zpool have grown in capacity. Therefore I have a zpool of 8 drives 1TB. If I need more capacity, I just swap them to 2TB or 4TB drives. Instead of adding more and more small drives that consume power and make noice. In the future, one drive will be 10TB. Then I regret I have lots of small drives. Therefore, I would make a zpool of 8 discs, configured as one raidz2. And add no more drives. Instead, I would swap the drives to larger and larger. If I had 16 drives, I would make two raidz2 groups. One raidz2 should consist of 6-8 drives. It is better to have several smaller groups in your zpool, than one large group - because each group increases performance. (Not sure on this: It is similar to one group gives you the performance of ONE drive. If you have 24 discs in one group, they will be slow as one drive, when talking about IOPS. If you have 8 discs in 3 groups, they will be fast as three drives, when talking about IOPS, i.e. head move speed and latency) if you mix sizes of discs, only the smallest size will be valid in one group. Say you have 500GB and 1TB drives. If you make one group, it will 500GB drives. The proper way would be to make two different groups (each one raidz1/raidz2), and add them to your zpool. Lastly, you must read ALL of these articles: http://breden.org.uk/2008/03/02/a-home-fileserver-using-zfs/ -- This message posted from opensolaris.org _______________________________________________ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
