Hi Timothy,

> I think that if you are running an illumos kernel, you can use
> /kernel/drv/sd.conf and tell it that the physical sectors for a disk
> model are 4k, despite what the disk says (and whether they really
> are).  So, if you want an ashift=12 pool on disks that report 512
> sectors, you should be able to do it now without a patched version of
> zpool.

That refers to creating a new pool and is good to know. However I was more
afraid about the comments in the "Advanced Format" threat stating that if
you have an ashift=9 512b based pool and need to replace a drive, resilver
might fail if you put in a 4K disk. Assuming that in 2-3 years you might not
be able to get 512b disks in the size you need them anymore, this could be a
serious problem.

> I think prtvtoc is all you need to determine
> if it is aligned, if the bytes/sector value under Dimensions is the
> true (physical) sector size, it should be aligned (if it reports 512
> when it has 4k sectors, then in theory if "First sector" is a multiple
> of 8, it is aligned, but it will probably issue writes of size 512
> which will degrade performance anyway).

Thanks. I will note that down and check once the drives arrive.

Kind regards,

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