Removing a VDEV while keeping data?

[cyberjock]

I'm in the process of setting up my first FreeNAS server. I've been playing around with it for a few days and getting familiar with the terminology. I've read through the manual and done some searching online, but I cannot find the answer to my question.

Currently, my new server will consist of 5x1.5TB drives and 5x1.0TB drives. My intention is to have 2 vdevs for each of the 2 drive sizes on a RAIDZ1(vdev1 for the 1.5TB drives and vdev2 for the 1TB drives). Total capacity will be 6TB 4TB for a total of 10TB in the pool. I'm using spare drives, otherwise I would be choosing something a little more consistent.

Overall, I'll be protected by one hard drive failure in each vdev. Now pretend that 6 months from now I decide that I want to replace the 1.5TB drives with 4TB drives and remove the 1TB drives completely. Is there a way to replace all of the drive in vdev1 then somehow "retire" the vdev2 drives so that the data they contain will be pushed back to vdev1? Or am I in a situation where I will always have to have 10 drives in the zpool. Obviously, I could create a new zpool, copy all of the data to the new zpool, then remove the old zpool. I was just hoping for simplicity I could avoid it.

Thanks!

 

[anudureio]

not until freebsd 8.3 release/integration in freenas I think, ZFS pool v15 is too old for doing this, ZFS pool v28 (freebsd 9.x forked in upcoming 8.3 as well) will allow you to do this, again I think

Code:

16	OpenSolaris Nevada b116	STMF property support
17	OpenSolaris Nevada b120	triple-parity RAID-Z
18	OpenSolaris Nevada b121	ZFS snapshot holds
19	OpenSolaris Nevada b125	ZFS log device removal
20	OpenSolaris Nevada b128	zle compression algorithm that is needed to support the ZFS deduplication properties in ZFS pool version 21, which were released concurrently.
21	OpenSolaris Nevada b128	Deduplication
22	OpenSolaris Nevada b128	zfs receive properties
23	OpenSolaris Nevada b135	slim ZIL
24	OpenSolaris Nevada b137	System attributes. symlinks now their own object type. Also requires FS v5
25	OpenSolaris Nevada b140	improved pool scrubbing and resilvering statistics
26	OpenSolaris Nevada b141	improved snapshot deletion performance.
27	OpenSolaris Nevada b145	improved snapshot creation performance (particularly recursive snapshots).
28	OpenSolaris Nevada b147	multiple virtual device replacements.

source & more info; http://en.wikipedia.org/wiki/ZFS#Release_history

 

[cyberjock]

Outstanding! I'm not going crazy. I was convinced I had read of the ability to do this somewhere, but I could find no reference to it on FreeNAS.

 

[louisk]

I don't see anything which indicates the ability to remove a vdev from a pool. Historically, this was a nono. You can add vdevs but you can't remove them. You can also change the size of spindles and and the vdev will grow once all drives have been upgraded (and resilvered).

The only way to accomplish this I can think of is to have separate pools and once you upgrade the 1.5 -> 4, move the data off the 1.0 and destroy that pool.