Solved [Solved] change ZFS ashift by replacing disks, possible?

W

wszczep

Hallo!

So I did a mistake. I already had a pool with one RAID-Z2 vdev created correctly with the gnop feature, so ashift was 12. Then I added to that pool another RAID-Z2 vdev but without creating gnop to at least one of disks. Now I've got two vdev's with different ashift.
Code: 
# zdb | grep ashift
            ashift: 12
            ashift: 9
But the disks' GPT partitions are aligned correctly, I took care to apply the -a4k -b2048 settings to the gpart create command.

Question: is it possible to change ashift from 9 to 12 by replacing disks with a spare gnop'ped disk? I mean:
Code: 
# gnop create -S 4096 /dev/gpt/spare_disk
# zpool replace some_tank /dev/gpt/some_disk_1 /dev/gpt/spare_disk.nop
then create gnop on that replaced disk, and use it again for replacing another disk, and so on.

My mistake was, that I thought of ashift to be set for the pool, not for the vdev group.
 
Re: [ZFS] change ashift by replacing disks, possible?

Once you create a VDEV the ashift property is fixed, it can not be changed later. I think it's possible to play tricks with detach/attach with mirror VDEVS to basically destroy the VDEV and create a new one with a larger ashift. The same can not be done with RAID-Z VDEVs unfortunately.
 
Re: [ZFS] change ashift by replacing disks, possible?

Ok. I will have to live with it. Thx Thanks for the answer.
 
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