Make ZFS use the physical sector size when computing initial ashift

[Borja Marcos]

On Jul 10, 2013, at 11:25 AM, Steven Hartland wrote:

> If others are interested I've attached this as it achieves what we needed here so
> may also be of use for others too.
> 
> There's also a big discussion on illumos about this very subject ATM so I'm
> monitoring that too.
> 
> Hopefully there will be a nice conclusion come from that how people want to
> proceed and we'll be able to get a change in that works for everyone.

Hmm. I wonder if the simplest approach would be the better. I mean, adding a flag to zpool.

At home I have a playground FreeBSD machine with a ZFS zmirror, and, you guessed it, I was
careless when I purchased the components, I asked for two "1 TB drives" and that I got, but different
models, one of them "advanced format" and the other one "classic".

I don't think it's that bad to create a pool on a classic disk using 4 KB blocks, and it's quite likely that
replacement disks will be 4 KB in the near future. 

Also, if you use SSDs the situation is similar.





Borja.