ZFS guidelines - preparing for future storage expansion

[Josh Carter]

On Nov 30, 2009, at 1:33 PM, Zaphod Beeblebrox wrote:

> This form of upgrade is a cool feature --- in the end the "cost" of running
> a home RAID array is the cost of the electricity ... and I'm pretty sure the
> draw of the 1.5T drives is very similar to the 750G drives.  I'm not sure I
> see this feature being used a lot in production, tho.  It's a pretty high
> stress on the array for a long time.

The best solution for production arrays hinges on this not-yet-done feature, allowing the removal of a top-level vdev when there's sufficient space on other vdevs:

http://bugs.opensolaris.org/bugdatabase/view_bug.do?bug_id=4852783

Assuming you've got several top-level vdevs, which is reasonable when you've got a lot of drives, you'd want to migrate data off a vdev, pull all the vdev's drives, and add new drives in their place. This both saves hands-on time and there's no additional vulnerability to data loss.

FWIW, I asked the bug's owner about the status of this feature back in April and he said "ETA into OpenSolaris this calendar year" but given that the "commit to fix" field of the bug is still blank, I consider it unlikely. One can still wish for a holiday gift. ;)

-Josh