[OpenIndiana-discuss] OI 151_a7 install on 4k sector disk

[Jim Klimov]

On 2013-01-26 22:17, Sašo Kiselkov wrote:
> Are you going to be using ZFS on those? If so, how does the ashift of a
> zpool created with them look like?
>
> # zdb <poolname> | grep ashift
>
> If it prints "ashift: 12", then you are good, zpool picked up the
> correct settings.


Well, to be pedantic, I'd add that ashift only dictates minimum block
size and alignment relative to the storage device provided to ZFS -
the slice or partition. Hardware-alignment of 4kb writes would also
need that the partition itself is aligned with 4KB sectors - i.e. that
its starting offset is divisible by 8 (in classic 512b sector count).
If you dedicate the disk to ZFS and it is automatically partitioned
with GPT, then the problem is taken care of - with offset being 256.
On MBR the default offset is 34 or so, and can present a problem that
is solvable by manual partitioning.

HTH,
//Jim