On 18 Jul 2006, Neil Brown moaned: > The superblock locations for sda and sda1 can only be 'one and the > same' if sda1 is at an offset in sda which is a multiple of 64K, and > if sda1 ends near the end of sda. This certainly can happen, but it > is by no means certain. > > For this reason, version-1 superblocks record the offset of the > superblock in the device so that if a superblock is written to sda1 > and then read from sda, it will look wrong (wrong offset) and so will > be ignored (no valid superblock here). One case where this can happen is Sun slices (and I think BSD disklabels too), where /dev/sda and /dev/sda1 start at the *same place*. (This causes amusing problems with LVM vgscan unless the raw devices are excluded, too.) -- `We're sysadmins. We deal with the inconceivable so often I can clearly see the need to define levels of inconceivability.' --- Rik Steenwinkel - To unsubscribe from this list: send the line "unsubscribe linux-raid" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
