emory wrote:If I were in that situation I would buy different disks, unless my wife forbid me.
Would there be any benefit to building a pool with three vdevs comprised of:
disk1+disk2, disk3, disk4
You could possibly achieve this if you used something external to ZFS to achieve the stripe (ala Apple RAID 0). I am not sure if Zevo will let you map an apple raid device, but assuming you could, you might be able to do something like:
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zpool create -f tank raidz /dev/stripe /dev/disk3 /dev/disk4
(substituting "stripe" for the real dev surfaced by the raid0 implementation)
emory wrote:Then if one of the disks in the stripe vdev of disk1+disk2 dies, you lose the whole vdev, but who cares, since it's raidz1 and you have the 2TB and 2.5TB disks still working?
While I think what you are saying is more or less correct, it looks like you confused the ZFS terminology slightly. To be clear, all four drives in this configuration would be a single "vdev" (a raidz vdev, to be precise). But to your point: Yes, disk1+disk2 would have the characteristics of a raid0 (that is, parallel reads+writes, no redundancy, loss of one disk is loss of entire raid0). But as you point out, when used in conjunction with ZFS, redundancy would be provided by the aggregate raidz vdev, where loss of the raid0 setup is just considered one "disk", and the other two should be able to reconstruct the missing data from parity across the other two.
I agree that if this works, it is probably superior to my suggestion. I am just not sure if it works or if it has any ramifications (e.g. perhaps the logical block size being larger on the raid0 when comared to disk3+4 might have some kind of negative performance impact).
Kind Regards,
-Greg