ashift on a new vdev mirror

[fumantsu]

I have a problem.
I have a pool with a mirrored vdev and I add to this pool one more mirrored vdev. The problem is that I discover that the second vdev wasn't "formated" for 4K even if I select the checkboxes on the vdev creation.

zdb |grep -i ashift
ashift: 12
ashift: 9

Now there is any way to change the ashift of the second vdev without destroy the universe?

[raulfg3]

no. sorry

but please test performance.

512 Vs 1024 (ashif 9 Vs ashif 12) it's not the end of the world, and probably you do not notice any degradation in your copy/move performance over Ethernet.

[fumantsu]

I will try the hard way removing the one big disk, copy data and then recreate all the pools from the scratch. But I'm wonder and I confirmed now, the second vdev was created with the "Advanced format" checked how is possible to be created without .nop, added to the pool from gui and result ashift=9?

Edit: from cli why I can't create a new pool with ashift=12?

Code: Select all

zpool create -o ashift=12 tank1 /dev/ada2.nop
property 'ashift' is not a valid pool property

[crowi]

ashift=12 is not a command, it is more or less just a result of formatting with 4k blocks

the command would be like

Code: Select all

gnop create -S 4096 /dev/da0

EDIT: here is a piece of explanation on this: http://ivoras.sharanet.org/blog/tree/20 ... rives.html

[fumantsu]

I didn't say that is command. Just a property. Most of guides (I can't figure if they applied to freebsd also) are using ashift as property in pool creation.

EDIT:
I get it. It still seems strange why the new vdev had ashift=9 as I made all the procedure from gui. Bug?

[kenZ71]

I will try the hard way removing the one big disk, copy data and then recreate all the pools from the scratch. But I'm wonder and I confirmed now, the second vdev was created with the "Advanced format" checked how is possible to be created without .nop, added to the pool from gui and result ashift=9?

This is also risky! I just did this last weekend had a mix up of my drives and destroy all my pools

Fortunately I did have the foresight to backup my most critical data to another PC prior to starting my adventure.

[fumantsu]

I done it like this. I wasn't so difficult, it was just need to be careful.
Steps:
snapshot
detach one big disk
create nop device
create a new pool with this one.
clone the snapshot
destroy the old pool.
create nop devices for all disks
Attach the second disk to the new pool
resilver
add as mirror the 2 other disks.
resilver

It took me 2 days for 2.7TB but everything now is as I want them. CLI will always rocks!