Understanding ASHIFT SSD and adding a mirrored vdev
Michael Jung
mikej at mikej.com
Thu May 15 12:15:15 UTC 2014
Hi:
I have read so many threads about ASHIFT on SSD my head is spinning.
This is my
current partition created with a 10-stable installer. 2x3TB drives in
mirror and
ashift=12 looks correct. I added the SSD which defaulted to ashift=9 and
this is where
my question is. Is alignment on SSD important as from what I read we
never really know
the flash layout? I hope there is a simply answer to this ;-)
Secondly, I want to add another vdev 2x mirrored 3tb drives and it seems
that ashift
would be vdev specific so I would need to gnop the new drives before add
the new vdev?
<gnop magic to create partition and set ashift=12>
then
zfs add zroot mirror ada3 ada4
Regards,
--mikej
root at firewall:/home/mikej # zdb -C zroot
MOS Configuration:
version: 5000
name: 'zroot'
state: 0
txg: 62296
pool_guid: 15958487588614144860
hostid: 2738252912
hostname: 'firewall'
vdev_children: 2
vdev_tree:
type: 'root'
id: 0
guid: 15958487588614144860
children[0]:
type: 'mirror'
id: 0
guid: 3592648208679324941
metaslab_array: 33
metaslab_shift: 34
ashift: 12
asize: 2983407648768
is_log: 0
create_txg: 4
children[0]:
type: 'disk'
id: 0
guid: 17048837379599232125
path:
'/dev/gptid/a514b75b-d9f9-11e3-9b31-001b211e2e44'
phys_path:
'/dev/gptid/a514b75b-d9f9-11e3-9b31-001b211e2e44'
whole_disk: 1
DTL: 157
create_txg: 4
children[1]:
type: 'disk'
id: 1
guid: 2010069802937618121
path:
'/dev/gptid/a604d635-d9f9-11e3-9b31-001b211e2e44'
phys_path:
'/dev/gptid/a604d635-d9f9-11e3-9b31-001b211e2e44'
whole_disk: 1
DTL: 156
create_txg: 4
children[1]:
type: 'disk'
id: 1
guid: 12355431372362468741
path: '/dev/ada2p1'
phys_path: '/dev/ada2p1'
whole_disk: 1
metaslab_array: 195
metaslab_shift: 26
ashift: 9
asize: 8585216000
is_log: 1
create_txg: 13825
features_for_read:
root at firewall:/home/mikej #
root at firewall:/home/mikej # zpool status
pool: zroot
state: ONLINE
status: Some supported features are not enabled on the pool. The pool
can
still be used, but some features are unavailable.
action: Enable all features using 'zpool upgrade'. Once this is done,
the pool may no longer be accessible by software that does not support
the features. See zpool-features(7) for details.
scan: scrub repaired 0 in 1h14m with 0 errors on Tue May 13 08:42:29
2014
config:
NAME STATE READ WRITE
CKSUM
zroot ONLINE 0 0
0
mirror-0 ONLINE 0 0
0
gptid/a514b75b-d9f9-11e3-9b31-001b211e2e44 ONLINE 0 0
0
gptid/a604d635-d9f9-11e3-9b31-001b211e2e44 ONLINE 0 0
0
logs
ada2p1 ONLINE 0 0
0
cache
ada2p2 ONLINE 0 0
0
errors: No known data errors
root at firewall:/home/mikej #
root at firewall:/home/mikej # gpart list ada0
Geom name: ada0
modified: false
state: OK
fwheads: 16
fwsectors: 63
last: 5860533134
first: 34
entries: 128
scheme: GPT
Providers:
1. Name: ada0p1
Mediasize: 524288 (512K)
Sectorsize: 512
Stripesize: 4096
Stripeoffset: 0
Mode: r0w0e0
rawuuid: a4adfc12-d9f9-11e3-9b31-001b211e2e44
rawtype: 83bd6b9d-7f41-11dc-be0b-001560b84f0f
label: gptboot0
length: 524288
offset: 20480
type: freebsd-boot
index: 1
end: 1063
start: 40
2. Name: ada0p2
Mediasize: 17179869184 (16G)
Sectorsize: 512
Stripesize: 4096
Stripeoffset: 0
Mode: r1w1e1
rawuuid: a4e5bce0-d9f9-11e3-9b31-001b211e2e44
rawtype: 516e7cb5-6ecf-11d6-8ff8-00022d09712b
label: swap0
length: 17179869184
offset: 544768
type: freebsd-swap
index: 2
end: 33555495
start: 1064
3. Name: ada0p3
Mediasize: 2983412547584 (2.7T)
Sectorsize: 512
Stripesize: 4096
Stripeoffset: 0
Mode: r1w1e2
rawuuid: a514b75b-d9f9-11e3-9b31-001b211e2e44
rawtype: 516e7cba-6ecf-11d6-8ff8-00022d09712b
label: zfs0
length: 2983412547584
offset: 17180413952
type: freebsd-zfs
index: 3
end: 5860533127
start: 33555496
Consumers:
1. Name: ada0
Mediasize: 3000592982016 (2.7T)
Sectorsize: 512
Stripesize: 4096
Stripeoffset: 0
Mode: r2w2e5
root at firewall:/home/mikej # gpart list ada1
Geom name: ada1
modified: false
state: OK
fwheads: 16
fwsectors: 63
last: 5860533134
first: 34
entries: 128
scheme: GPT
Providers:
1. Name: ada1p1
Mediasize: 524288 (512K)
Sectorsize: 512
Stripesize: 4096
Stripeoffset: 0
Mode: r0w0e0
rawuuid: a5a0aa88-d9f9-11e3-9b31-001b211e2e44
rawtype: 83bd6b9d-7f41-11dc-be0b-001560b84f0f
label: gptboot1
length: 524288
offset: 20480
type: freebsd-boot
index: 1
end: 1063
start: 40
2. Name: ada1p2
Mediasize: 17179869184 (16G)
Sectorsize: 512
Stripesize: 4096
Stripeoffset: 0
Mode: r1w1e1
rawuuid: a5d8019e-d9f9-11e3-9b31-001b211e2e44
rawtype: 516e7cb5-6ecf-11d6-8ff8-00022d09712b
label: swap1
length: 17179869184
offset: 544768
type: freebsd-swap
index: 2
end: 33555495
start: 1064
3. Name: ada1p3
Mediasize: 2983412547584 (2.7T)
Sectorsize: 512
Stripesize: 4096
Stripeoffset: 0
Mode: r1w1e2
rawuuid: a604d635-d9f9-11e3-9b31-001b211e2e44
rawtype: 516e7cba-6ecf-11d6-8ff8-00022d09712b
label: zfs1
length: 2983412547584
offset: 17180413952
type: freebsd-zfs
index: 3
end: 5860533127
start: 33555496
Consumers:
1. Name: ada1
Mediasize: 3000592982016 (2.7T)
Sectorsize: 512
Stripesize: 4096
Stripeoffset: 0
Mode: r2w2e5
root at firewall:/home/mikej # gpart list ada2
Geom name: ada2
modified: false
state: OK
fwheads: 16
fwsectors: 63
last: 250069646
first: 34
entries: 128
scheme: GPT
Providers:
1. Name: ada2p1
Mediasize: 8589934592 (8.0G)
Sectorsize: 512
Stripesize: 0
Stripeoffset: 17408
Mode: r1w1e1
rawuuid: 31d66c14-daba-11e3-a0ae-001b211e2e44
rawtype: 516e7cba-6ecf-11d6-8ff8-00022d09712b
label: logs
length: 8589934592
offset: 17408
type: freebsd-zfs
index: 1
end: 16777249
start: 34
2. Name: ada2p2
Mediasize: 119445707264 (111G)
Sectorsize: 512
Stripesize: 0
Stripeoffset: 17408
Mode: r1w1e1
rawuuid: 37b41a84-daba-11e3-a0ae-001b211e2e44
rawtype: 516e7cba-6ecf-11d6-8ff8-00022d09712b
label: cache
length: 119445707264
offset: 8589952000
type: freebsd-zfs
index: 2
end: 250069646
start: 16777250
Consumers:
1. Name: ada2
Mediasize: 128035676160 (119G)
Sectorsize: 512
Mode: r2w2e4
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