ZFS and Samsung Spinpoint F4 4K sector drive

[Xin LI]

On Thu, Oct 7, 2010 at 6:53 PM, Adam Nowacki <nowak at xpam.de> wrote:
> Nothing user friendly but if you're willing to modify sources and rebuild
> kernel there is a one line tweak.
> /usr/src/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/vdev_geom.c find:
> *ashift = highbit(MAX(pp->sectorsize, SPA_MINBLOCKSIZE)) - 1;
> and modify to something like:
> *ashift = highbit(MAX(MAX(4096, pp->sectorsize), SPA_MINBLOCKSIZE)) - 1;
> I'm using this for 3 months with 20 2TB 4kb sector WDC disks (in 2 raidz2
> arrays of 10) without any issues. Writes go at 300MB/s.

Just a suggestion - pp->stripesize might be better than hard coding
4096 for here when the drive, potentially a hardware RAID or some SSD,
etc, and reports a higher value via GEOM framework.

Cheers,
-- 
Xin LI <delphij at delphij.net> http://www.delphij.net