>> If that is the case, then here is what I would expect my values to
>> be: sunit = 512
>> swidth = 4608
> I think sunit should be as big as the RAID controllers stripe size, as
> it describes the smallest I/O XFS should do. So sunit=512 would make it
> possible that XFS writes a single sector, while the RAID controller
> needs to read/write 256KB with your stripe size, resulting in
> performance degradation. But I'm no XFS dev, so maybe wait for a
> clearing from someone who has deeper XFS knowledge than me.
> Would be my suggestion for your setup.
IIRC sunit and swidth are both specified in units of 512 bytes (don't
ask me why) so a sunit value of 512 would mean 256KB stripe size which
is correct :-)
If i am right, the FAQ should be corrected (hopefully some dev can