In many large datacenters, a different storage team handles LUN requests and assignment. We ask a LUN in a specific size, and we get one.
It might result that the first vdev (LUN) is on a beginning of a RAID set on the storage, and the second vdev is on the end of the same RAID set on the same physical disks. (If not in the creation time, then later, during the increase of a filled zpool, by adding a LUN) I worry about head thrashing. Though memory cache of large storage should make the problem easier, I would be more happy if I can be sure that zpool will not be handled as a stripe. Is there a way to avoid it, or can we be sure that the problem does not exist at all ? -----Original Message----- From: Darren J Moffat [mailto:darr...@opensolaris.org] Sent: 2010. október 18. 10:19 To: Habony, Zsolt Cc: zfs-discuss@opensolaris.org Subject: Re: [zfs-discuss] How to avoid striping ? On 18/10/2010 07:44, Habony, Zsolt wrote: > I have seen a similar question on this list in the archive but haven't > seen the answer. > > Can I avoid striping across top level vdevs ? > > If I use a zpool which is one LUN from the SAN, and when it becomes full > I add a new LUN to it. > > But I cannot guarantee that the LUN will not come from the same spindles > on the SAN. That sounds like a problem with your SAN config if that matters to you. > Can I force zpool to not to stripe the data ? You can't, but why do you care ? -- Darren J Moffat _______________________________________________ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
