Problems replacing failing drive in ZFS pool

[Charles Sprickman]

On Wed, 21 Jul 2010, Charles Sprickman wrote:

> On Tue, 20 Jul 2010, alan bryan wrote:
>
>> 
>> 
>> --- On Mon, 7/19/10, Dan Langille <dan at langille.org> wrote:
>> 
>>> From: Dan Langille <dan at langille.org>
>>> Subject: Re: Problems replacing failing drive in ZFS pool
>>> To: "Freddie Cash" <fjwcash at gmail.com>
>>> Cc: "freebsd-stable" <freebsd-stable at freebsd.org>
>>> Date: Monday, July 19, 2010, 7:07 PM
>>> On 7/19/2010 12:15 PM, Freddie Cash
>>> wrote:
>>> > On Mon, Jul 19, 2010 at 8:56 AM, Garrett Moore<garrettmoore at gmail.com> 
>>> wrote:
>>> >> So you think it's because when I switch from the
>>> old disk to the new disk,
>>> >> ZFS doesn't realize the disk has changed, and
>>> thinks the data is just
>>> >> corrupt now? Even if that happens, shouldn't the
>>> pool still be available,
>>> >> since it's RAIDZ1 and only one disk has gone
>>> away?
>>> > > I think it's because you pull the old drive, boot with
>>> the new drive,
>>> > the controller re-numbers all the devices (ie da3 is
>>> now da2, da2 is
>>> > now da1, da1 is now da0, da0 is now da6, etc), and ZFS
>>> thinks that all
>>> > the drives have changed, thus corrupting the
>>> pool.  I've had this
>>> > happen on our storage servers a couple of times before
>>> I started using
>>> > glabel(8) on all our drives (dead drive on RAID
>>> controller, remove
>>> > drive, reboot for whatever reason, all device nodes
>>> are renumbered,
>>> > everything goes kablooey).
>>> 
>>> Can you explain a bit about how you use glabel(8) in
>>> conjunction with ZFS?  If I can retrofit this into an
>>> exist ZFS array to make things easier in the future...
>>> 
>>> 8.0-STABLE #0: Fri Mar  5 00:46:11 EST 2010
>>> 
>>> ]# zpool status
>>>   pool: storage
>>>  state: ONLINE
>>>  scrub: none requested
>>> config:
>>>
>>>         NAME STATE     READ WRITE CKSUM
>>>         storage
>>>    ONLINE
>>>    0     0
>>>    0
>>>           raidz1 ONLINE       0
>>>    0     0
>>>             ad8
>>>    ONLINE
>>>    0     0
>>>    0
>>>             ad10 ONLINE       0
>>>    0     0
>>>             ad12 ONLINE       0
>>>    0     0
>>>             ad14 ONLINE       0
>>>    0     0
>>>             ad16 ONLINE       0
>>>    0     0
>>> 
>>> > Of course, always have good backups.  ;)
>>> 
>>> In my case, this ZFS array is the backup.  ;)
>>> 
>>> But I'm setting up a tape library, real soon now....
>>> 
>>> -- Dan Langille - http://langille.org/
>>> _______________________________________________
>>> freebsd-stable at freebsd.org
>>> mailing list
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>>> 
>> 
>> Dan,
>> 
>> Here's how to do it after the fact:
>> 
>> http://unix.derkeiler.com/Mailing-Lists/FreeBSD/current/2009-07/msg00623.html
>
> Two things:
>
> -What's the preferred labelling method for disks that will be used with zfs 
> these days?  geom_label or gpt labels?  I've been using the latter and I find 
> them a little simpler.
>
> -I think that if you already are using gpt partitioning, you can add a gpt 
> label after the fact (ie: gpart -i index# -l your_label adaX).  "gpart list" 
> will give you a list of index numbers.

Oops.

That should be "gpart modify -i index# -l your_label adax".

> Charles
>
>> --Alan Bryan
>> _______________________________________________
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>> http://lists.freebsd.org/mailman/listinfo/freebsd-stable
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>