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I have a FreeBSD system with a 750GB boot drive (UFS boot, ZFS root) and a second data made from a three drive raidz setup. I'd like to swap the three 250GB drives for a trio of 2TB drives. Assuming that I have enough room on the root drive to make a copy of all the date from the raidz setup, what would be the simplest way to swap out the drives?

Should I just copy out all of the data, destroy the pool, power down the system and install the drives and then boot and recreate the pool and then the file systems. Then restore the data back to where it was?

Is there something that I can do that would be less work?

This is on a 1U rack mount running FreeBSD 7.2 (Built from sources on 20090920).

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up vote 2 down vote accepted

I found the answer that I was looking for:

zpool offline tank drivename
<Remove drive>
zpool replace tank drivename
zpool export tank
zpool import tank

This way, I will not have to delete and recreate the zpool and all of the file systems. I'm going to have to think about this.

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IMO, drive-by-drive migration from 250Gb drives to 2Tb is the best way to increase raidz capacity – SaveTheRbtz Sep 29 '09 at 23:55

Backing up and restoring is probably the easier way to do it. I think that you can replace the drives one at a time, but that would require three reboots and it's dangerous since you will be running with a degraded array. To back up the data I would recommend using zfs send and zfs receive, which should make the backup and restore process quick and easy.

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