ZFS auto expand mirror

[Freddie Cash]

Once all of the disks in the vdev have been replaced, making them all the
same size. Doesn't matter in what order they are replaced.

Freddie
fjwcash at gmail.com
On Sep 19, 2011 4:30 PM, "Jeremy Chadwick" <freebsd at jdc.parodius.com> wrote:
> On Mon, Sep 19, 2011 at 02:54:06PM -0700, Freddie Cash wrote:
>> On Mon, Sep 19, 2011 at 2:38 PM, Jeremy Chadwick
>> <freebsd at jdc.parodius.com>wrote:
>>
>> > On Mon, Sep 19, 2011 at 10:49:56AM -0700, Freddie Cash wrote:
>> > > On Mon, Sep 19, 2011 at 10:08 AM, Ben Stuyts <ben at altesco.nl> wrote:
>> > >
>> > > > I want to expand an existing mirror by replacing the existing
drives
>> > with
>> > > > bigger ones. This is on:
>> > > > FreeBSD xxx 7.3-STABLE FreeBSD 7.3-STABLE #2: Mon Sep 20 18:36:08
CEST
>> > 2010
>> > > > root at xxx:/usr/obj/usr/src/sys/xxx amd64
>> > > >
>> > > > # zpool status home
>> > > > pool: home
>> > > > state: ONLINE
>> > > > scrub: scrub completed after 2h0m with 0 errors on Mon Sep 19
18:25:45
>> > > > 2011
>> > > > config:
>> > > >
>> > > > NAME STATE READ WRITE CKSUM
>> > > > home ONLINE 0 0 0
>> > > > mirror ONLINE 0 0 0
>> > > > ad5s1a ONLINE 0 0 0
>> > > > ad7s1a ONLINE 0 0 0
>> > > >
>> > > > Will this version of FreeBSD auto-expand to the new, bigger drive
size
>> > once
>> > > > they are both replaced? I did not see the autoexpand property in
this
>> > pool.
>> > > > zpool is v13, zfs is v3.
>> > > >
>> > >
>> > > No. You will need to reboot the system in order for the extra space
to
>> > > become usable in the pool. Or, if none of the OS is installed on the
>> > pool,
>> > > you can export/import the pool to make the new space available.
>> >
>> > Does this advice/fact apply to FreeBSD 7.3? To my knowledge it does
>> > not. The ZFS version is too old.
>>
>> It's worked for me on our storage servers. These started with ZFSv6 and
>> have been upgraded through each version, currently running ZFSv28 on
>> 8-STABLE.
>>
>> Early versions of ZFS need the reboot or export/import cycle. Newer
>> versions pick up the new space as soon as the resilver of the last drive
in
>> the vdev occurs (if the autoexpand property is enabled on the pool).
>
> I was about to ask what the autoexpand property was for then, but you've
> answered it in your 2nd paragraph here.
>
> Also, need some clarification here: when you say "the last drive in the
> vdev" do you effectively mean "once all the drives in the vdev are of
> the same size", or do you quite literally mean "the last device/disk
> shown in the vdev"?
>
> I can't imagine the latter being correct but I want clarification for
> myself as well as others who read this. Thanks!
>
> --
> | Jeremy Chadwick jdc at parodius.com |
> | Parodius Networking http://www.parodius.com/ |
> | UNIX Systems Administrator Mountain View, CA, US |
> | Making life hard for others since 1977. PGP 4BD6C0CB |
>