ZFS guidelines - preparing for future storage expansion

[Zaphod Beeblebrox]

On Mon, Nov 30, 2009 at 7:25 AM, Wiktor Niesiobedzki <bsd at w.evip.pl> wrote:

> 2009/11/30 James R. Van Artsdalen <james-freebsd-fs2 at jrv.org>:
> > Wiktor Niesiobedzki wrote:
> >> do I need to do something more, to get new space used by
> >> RAIDZ?
> >
> > Export the pool, the import it.  Adding a vdev is done right away, but
> > increasing the size of a vdev (as you did) only happens on import.
> >
>
> That did the trick, thanks :-) Cool thing! :-)
>

Wasn't a reboot also an option (which might disturb active NFS mounts less)?

I moved from 5x 750G to 5x 1.5T disks this way earlier this year.  It takes
a _long_ time.  resilvering 750g (they were about 98% full when I did this)
onto the 1.5T disks took about 12 hours each.  With work and sleep and other
distractions, it took most of a week to perform the upgrade.  And keep in
mind that while you're upgrading, you're vulnerable to data loss (no more
replicas). I suppose RAIDZ2 would make that safer, but more costly.

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.