Klistvud: > Dne, 09. 01. 2011 17:35:07 je Jochen Schulz napisal(a): >> Klistvud: >>> >>> After partitioning the drive, aligned on modulo 8 sector boundaries: >>> >>> obelix:# hdparm -tT /dev/sda >> >> Your test is unsuitable to detect any alignment-related performance >> issues. > > Care to elaborate why?
Because that's streaming big chunks from the disk and that doesn't
trigger any alignment issues. The problem about alignment is that
accessing a single, unaligned filesystem block makes it necessary for
the disk to read two blocks instead of one.
As I understand it, this issue mostly impacts random access performance.
I don't know of any reliable way to test this, but you need to test a
filesystem, not a raw disk device.
J.
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