On Mar 19, 2010, at 5:32 AM, Chris Dunbar - Earthside, LLC wrote: > Hello, > > After being immersed in this list and other ZFS sites for the past few weeks > I am having some doubts about the zpool layout on my new server. It's not too > late to make a change so I thought I would ask for comments. My current plan > to to have 12 x 1.5 TB disks in a what I would normally call a RAID 10 > configuration. That doesn't seem to be the right term here, but there are 6 > sets of mirrored disks striped together. I know that "smaller" sets of disks > are preferred, but how small is small? I am wondering if I should break this > into two sets of 6 disks. I do have a 13th disk available as a hot spare. > Would it be available for either pool if I went with two? Finally, would I be > better off with raidz2 or something else instead of the striped mirrored > sets? Performance and fault tolerance are my highest priorities.
Do you believe in coincidence? :-) I recently blogged about the reliability analysis using 12 disks as a representative sample. I didn't add a hot spare for this analysis, but it would help in all cases. http://blog.richardelling.com/2010/02/zfs-data-protection-comparison.html For those disinclined to click, data retention when mirroring wins over raidz when looking at the problem from the perspective of number of drives available. Why? Because 5+1 raidz survives the loss of any disk, but 3 sets of 2-way mirrors can survive the loss of 3 disks, as long as 2 of those disks are not in the same set. The rest is just math. -- richard ZFS storage and performance consulting at http://www.RichardElling.com ZFS training on deduplication, NexentaStor, and NAS performance Las Vegas, April 29-30, 2010 http://nexenta-vegas.eventbrite.com _______________________________________________ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
