Date: Wed, 12 Oct 2011 12:31:16 -0500 (CDT) From: Larry Rosenman <ler@lerctr.org> To: Tom Evans <tevans.uk@googlemail.com> Cc: freebsd-fs@freebsd.org Subject: Re: AF (4096 byte sector) drives: Can you mix/match in a ZFS pool? Message-ID: <alpine.BSF.2.00.1110121229570.17730@lrosenman.dyndns.org> In-Reply-To: <CAFHbX1K5O%2BGeO-9LixbLi=V=77O5D1g93UC%2BQSN4-s0hEm0aDw@mail.gmail.com> References: <4E95AE08.7030105@lerctr.org> <CAFHbX1K5O%2BGeO-9LixbLi=V=77O5D1g93UC%2BQSN4-s0hEm0aDw@mail.gmail.com>
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On Wed, 12 Oct 2011, Tom Evans wrote:
> On Wed, Oct 12, 2011 at 4:11 PM, Larry Rosenman <ler@lerctr.org> wrote:
>> I have a root on ZFS box with 6 drives, all 400G (except one 500G) in a
>> pool.
>>
>> I want to upgrade to 2T or 3T drives, but was wondering if you can mix/match
>> while doing the drive by drive
>> replacement.
>>
>> This is on 9.0-BETA3 if that matters.
>>
>> Thanks!
>>
>
> Hi Larry
>
> I'm in a similar position. I have a 2 x 6 x 1.5TB raidz system,
> configured a while ago when I wasn't aware enough of 4k sector drives,
> and so ZFS is configured to use 512 byte sectors (ashift=9). All of
> the drives in it were 512 byte sector drives, until one of them
> failed.
>
> At that point, I couldn't lay my hands on a large capacity drive that
> still used 512 byte sectors, so I replaced it with a 4k sector drive,
> made sure it was aligned correctly, and hoped for the best. The
> performance sucks (500MB/s reads -> 150MB/s reads!), but it 'works',
> all my data is safe.
>
> The solution is to make sure that all your vdevs, whether they are
> backed by disks that have 512 byte or 4k sectors, are created with 4k
> sectors (ashift=12). It won't negatively affect your older disks, and
> you won't end up in the position I am in, where I need to recreate the
> pool to fix the issue (and have 12TB of data with nowhere to put it!)
>
I wish I had asked this question BEFORE I made the box Root on ZFS on Saturday.
Here's what I have:
pool: zroot
state: ONLINE
scan: scrub repaired 0 in 0h20m with 0 errors on Sat Oct 8 22:21:50 2011
config:
NAME STATE READ WRITE CKSUM
zroot ONLINE 0 0 0
raidz1-0 ONLINE 0 0 0
gpt/disk0 ONLINE 0 0 0
gpt/disk1 ONLINE 0 0 0
gpt/disk2 ONLINE 0 0 0
gpt/disk3 ONLINE 0 0 0
gpt/disk4 ONLINE 0 0 0
gpt/disk5 ONLINE 0 0 0
errors: No known data errors
zroot:
version: 28
name: 'zroot'
state: 0
txg: 185
pool_guid: 6776217281607456243
hostname: ''
vdev_children: 1
vdev_tree:
type: 'root'
id: 0
guid: 6776217281607456243
children[0]:
type: 'raidz'
id: 0
guid: 1402298321185619698
nparity: 1
metaslab_array: 30
metaslab_shift: 34
ashift: 9
asize: 2374730514432
is_log: 0
create_txg: 4
children[0]:
type: 'disk'
id: 0
guid: 9076139076816521807
path: '/dev/gpt/disk0'
phys_path: '/dev/gpt/disk0'
whole_disk: 1
create_txg: 4
children[1]:
type: 'disk'
id: 1
guid: 1302481463702775221
path: '/dev/gpt/disk1'
phys_path: '/dev/gpt/disk1'
whole_disk: 1
create_txg: 4
children[2]:
type: 'disk'
id: 2
guid: 15500000621616879018
path: '/dev/gpt/disk2'
phys_path: '/dev/gpt/disk2'
whole_disk: 1
create_txg: 4
children[3]:
type: 'disk'
id: 3
guid: 11011035160331724516
path: '/dev/gpt/disk3'
phys_path: '/dev/gpt/disk3'
whole_disk: 1
create_txg: 4
children[4]:
type: 'disk'
id: 4
guid: 17522530679015716424
path: '/dev/gpt/disk4'
phys_path: '/dev/gpt/disk4'
whole_disk: 1
create_txg: 4
children[5]:
type: 'disk'
id: 5
guid: 16647118440423800168
path: '/dev/gpt/disk5'
phys_path: '/dev/gpt/disk5'
whole_disk: 1
create_txg: 4
So, is there a way to change/fix/whatever this setup and not have to copy
40+G of data?
Thanks for the reply!
--
Larry Rosenman http://www.lerctr.org/~ler
Phone: +1 512-248-2683 E-Mail: ler@lerctr.org
US Mail: 430 Valona Loop, Round Rock, TX 78681-3893
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