On Mon, Jun 13, 2011 at 6:01 PM, Erik Trimble <erik.trim...@oracle.com> wrote:
> I'd have to re-look at the exact numbers, but, I'd generally say that
> 2x6raidz2 vdevs would be better than either 1x12raidz3 or 4x3raidz1 (or
> 3x4raidz1, for a home server not looking for super-critical protection (in
> which case, you should be using mirrors with spares, not raidz*).
I saw some stats a year or more ago that indicated the MTDL for raidZ2
was better than for a 2-way mirror. In order of best to worst I
remember the rankings as:
raidZ3 (least likely to lose data)
3-way mirror
raidZ2
2-way mirror
raidZ1 (most likely to lose data)
This is for Mean Time to Data Loss, or essentially the odds of losing
_data_ due to one (or more) drive failures. I do not know if this took
number of devices per vdev and time to resilver into account.
Non-redundant configurations were not even discussed. This information
came out of Sun (pre-Oracle) and _may_ have been traceable back to
Brendan Gregg.
--
{--------1---------2---------3---------4---------5---------6---------7---------}
Paul Kraus
-> Senior Systems Architect, Garnet River ( http://www.garnetriver.com/ )
-> Sound Coordinator, Schenectady Light Opera Company (
http://www.sloctheater.org/ )
-> Technical Advisor, RPI Players
_______________________________________________
zfs-discuss mailing list
zfs-discuss@opensolaris.org
http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
