4k alignment for attaching new disk to zfs mirror

Karolis Eigelis karolis.eigelis at gmail.com
Mon Oct 8 14:31:11 UTC 2012


Before creating a pool i setup two disks mirror with gnop trick to have
ashift=12 - 4k pool alignment. I also did that for the disk partitions (gpt
-a 4k option) to have partitions 4k alignment (diskinfo -v disk shows
stripesize=4096 for both disks).

Now i replaced one disk with a new one, but cant get the diskinfo or gpart
list to display stripesize=4096 - did everything as usual (gpt -a 4k for
partitions). Or do i have to re-create my pool with gnop trick again ?

Do you have an idea if that at all is needed ? Some other information i
found says that as long as pool is 4k alignment is done (ashif=12) you do
not need to do 4k alignment for new disk for partitions with gpart -a 4k
option. Could someone please comment on that ?

Many Thanks,

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