Hours of tiny transfers at the end of a ZFS resilver?

Freddie Cash fjwcash at gmail.com
Tue Feb 16 02:28:09 UTC 2016

On Feb 15, 2016 5:30 PM, "Paul Kraus" <paul at kraus-haus.org> wrote:
> On Feb 15, 2016, at 16:35, Gary Palmer <gpalmer at freebsd.org> wrote:
> > It should be noted that ZFS can do the right thing only at pool creation
> > time.  Once the pool has been created the sector size of the underlying
> > disks is baked in and can only be changed by creating a new pool on
> > the advanced format disks (or forcing the larger ashift value when
> > you initially create the pool, even if the disks are really 512 byte
> > sector drives)
> Is it baked in at the pool layer or the vdev layer ? I thought the ashift
was set on a vdev by vdev basis.

ashift property is set per vdev, and is set when the vdev is created. You
cab have multiple different ashift values in a single pool, although it may
be detrimental to performance.

You can see the ashift value via

"zdb poolname | grep ashift"


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