[zfs-discuss] How many disk in one pool

[Edward Ned Harvey (opensolarisisdeadlongliveopensolaris)]

> From: zfs-discuss-bounces at opensolaris.org [mailto:zfs-discuss-
> bounces at opensolaris.org] On Behalf Of Albert Shih
> 
> I'm actually running ZFS under FreeBSD. I've a question about how many
> disks I <can> have in one pool.
> 
> At this moment I'm running with one server (FreeBSD 9.0) with 4 MD1200
> (Dell) meaning 48 disks. I've configure with 4 raidz2 in the pool (one on
> each MD1200)
> 
> On what I understand I can add more more MD1200. But if I loose one
> MD1200
> for any reason I lost the entire pool.
> 
> In your experience what's the <limit> ? 100 disk ?
> 
> How FreeBSD manage 100 disk ? /dev/da100 ?

Correct about if you lose one storage tray you lose the pool.  Ideally you would span your redundancy across trays as well as across disks - but in your situation, 12 disks in raidz2 - and 4 trays - it's just not realistic for you.  You would have to significantly increase cost (not to mention rebuild pool) in order to keep the same available disk space and gain the redundancy.

Go ahead and add more trays.  I've never heard of any limit of number of disks you can have in ZFS.  I'm sure there is a limit, but whatever it is, you're nowhere near it.