Ron Johnson put forth on 7/3/2010 2:36 PM:
This is unrelated. FS block size != sector size.
It is when you use a 4KB drive!!!!
Not according to man on Stable:
mkfs.xfs [ -b block_size ] ... [ -s sector_size ] [ -L label ] [ -N ] device
-b block_size_options
This option specifies the fundamental block size of the filesystem. The
valid block_size_options are: log=value or size=value and only one can be
supplied. The block size is specified either as a base two logarithm value
with log=, or in bytes with size=. The default value is 4096 bytes (4 KiB),