On Wed, Jun 2, 2010 at 3:54 PM, Roman Naumenko <ro...@naumenko.ca> wrote: > And some time before I had suggested to a my buddy zfs for his new home > storage server, but he turned it down since there is no expansion available > for a pool.
There's no expansion for aggregates in OnTap, either. You can add more disks (as a raid-dp or mirror set) to an existing aggr, but you can also add more vdevs (as raidz or mirrors) to a zpool two. > And he really wants to be able to add a drive or couple to an existing pool. > Yes, there are ways to expand storage to some extent without rebuilding it. > Like replacing disk with larger ones. Not enough for a typical home user I > would say. You can do this. 'zpool add' > Nevertheless, NetApp appears to have such feature as I learned from my > co-worker. It works with some restrictions (you have to zero disks before > adding, and rebalance the aggregate after and still without perfect > distribution) - but Ontap is able to do aggregates expansion nevertheless. Yeah, you can add to a aggr, but you can't add to a raid-dp set. It's the same as ZFS. ZFS doesn't require that you zero disks, and there is no rebalancing. As more data is written to the pool it will become more balanced however. > So, my question is: what does prevent to introduce the same for zfs at > present time? Is this because of the design of zfs, or there is simply no > demand for it in community? > > My understanding is that at present time there are no plans to introduce it. Rebalancing depends on bp_rewrite, which is vaporware still. There has been discussion of it for a while but no implementation that I know of. Once the feature is added, it will be possible to add or remove devices from a zpool or vdev, something that OnTap can't do. -B -- Brandon High : bh...@freaks.com _______________________________________________ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
