Status of support for 4KB disk sectors

[Chuck Swiger]

On Jul 19, 2011, at 12:29 PM, Ivan Voras wrote:
>> Is there something in FreeBSD which is preventing you from using the drive's native DEV_BSIZE of 4096 bytes, or is it that the drive claims to have a physical block size of 512 bytes when it is really 4k?
> 
> Nope, "only" that.

:-)

It's nice to have well-defined problems-- although it's perhaps not so nice when hardware is compelled to lie about its status because of backwards-compatibility (C/H/S vs LBA comes to mind also).

> The current state of the matter (i.e. for 9.0) is:
> 
> * The new ATA driver has quirks for certain models of HDDs which have this false advertising (which can be manually triggered by kern.cam.ada.X.quirks=1) which causes the drive to report stripesize of 4k.
> 
> * This information is used in gpart to size & align partitions; it will be used by the new installer
> 
> * Default fragment size for UFS was raised to 4K so it will be aligned by default.

Excellent; thanks for the detailed reply.

Regards,
-- 
-Chuck