On Mon, 27 Apr 2009, Michael Shadle wrote:
I was still operating under the impression that vdevs larger than 7-8
disks typically make baby Jesus nervous.
Baby Jesus might not be particularly nervous but if your drives don't
perform consistently, then there will be more chance of performance
loss. With raidz and raidz2 the drives need to operate in
synchronicity so a balky drive (e.g. longer seek times than the others
or slow transfers) will hurt performance. Naturally, the more money
you try to save, the more chance you have of a balky drive. If you
find one, you can replace it and replace drives until there are no
more laggards left.
From what I have heard, there are limits to how many drives can be
included in a ZFS block write so an individual write is not likely to
span all of the drives, which makes finding the balky drives more
interesting.
Bob
--
Bob Friesenhahn
bfrie...@simple.dallas.tx.us, http://www.simplesystems.org/users/bfriesen/
GraphicsMagick Maintainer, http://www.GraphicsMagick.org/
_______________________________________________
zfs-discuss mailing list
zfs-discuss@opensolaris.org
http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
