Brandon High wrote:
On Thu, Apr 1, 2010 at 11:46 AM, Carson Gaspar <car...@taltos.org
<mailto:car...@taltos.org>> wrote:
"Nonsensical" may be a bit strong, but I can see no possible use
case where a 3 disk raidz2 isn't better served by a 3-way mirror.
Once bp_rewrite is done, you'll be able add disks to the raidz2. I
suppose that's one reason?
If you can expand a raidz2, you should be able to convert a mirror into
a raidz2.
Actually, you can do that now (with some trickery):
- zpool detach oldpool exmirror3
- Add your new disk(s) to the system
- mkfile /blah/fake1; mkfile /blah/fake2
- zpool create newpool raidz2 exmirror3 newdisk1 [newdisk2...] fake1 fake2
- zpool offline newpool fake1 fake2
- copy oldpool to newpool with zfs send/recv
- zpool detach oldpool exmirror2
- zpool replace newpool fake2 exmirror2
- zpool destroy oldpool
- zpool replace newpool fake1 exmirror1
3-way mirror becomes 4 or more disk raidz2 while retaining redundancy
except for the brief period when you are running with a single disk old
pool and a resilvering raidz2, and even then you have 2 copies of your data.
Sneaky, eh?
--
Carson
_______________________________________________
zfs-discuss mailing list
zfs-discuss@opensolaris.org
http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
