On Tue, Jul 24, 2012 at 05:31:50PM +1000, Toby Corkindale wrote:
However there do seem to be a lot of disks that mis-report their physical sector size. Why would that be?
Windows. specifically Windows XP. Lots of 4K sector drives lie to the operating system in order to remain compatible with WinXP. This is less common than it used to be but hasn't vanished entirely yet. This is why it's best (as you mention) to always align partitions as if it were a 4K drive - 4096 bytes is a multiple of 512 bytes so it works for both. this is also why it's a good idea to use '-o ashift=12' when creating a ZFS vdev, in case you have a lying 4K sector drive *or* you may want to replace the drives with 4K sector drives in future. craig -- craig sanders <cas@taz.net.au>