Support for WD Advanced Format disks

[Valentin Nechayev]

> I'm looking into a clean, permanent solution for WD Green drives that
> use 4096-byte physical sectors.  To summarize the information I've
> collected so far:

There is attempt to look from another side - is it really needed?
Captain Obvious says that if one have a new disk, it's easy to format
it properly - i.e. not xxx*16*63 but aligned on 4KB boundary. For
example, set up geometry xxx*64*32 for all new disks and align GPT
partitions on 1MB boundary. As soon as FS requests in FreeBSD are no
less than 4KB in size, this would satisfy any disk.

If 4KB sectors are our future for a few next years, this shall be
implemented anyway...


-netch-