On Sun, 2008-05-04 at 21:20 +1000, Neil Brown wrote: > On Friday May 2, russ@xxxxxxxxxxx wrote: > > > > My plan basically was: > > > > # remove one small disk > > /sbin/mdadm /dev/md0 --fail /dev/sdb1 > > /sbin/mdadm /dev/md0 --remove /dev/sdb1 > > > > # shutdown and swap in large disk > > # (with larger partition for the RAID1 component) > > # add large drive into array > > /sbin/mdadm /dev/md0 --add /dev/sdb1 > > > > # Allow the array to resync > > # remove the remaining small drive > > /sbin/mdadm /dev/md0 --fail /dev/sda1 > > /sbin/mdadm /dev/md0 --remove /dev/sda1 > > > > # Grow the array > > /sbin/mdadm -G /dev/md0 -z max > > > > # shutdown and swap in second large disk > > # (with larger partition for the RAID1 component) > > # add in the second large drive > > /sbin/mdadm /dev/md0 --add /dev/sda1 > > > > My concern (based on this discussion) is that this will fail because I > > am changing the size of the partition underlying the RAID1 array, much > > like the LVM discussion above, while using ver 0.90 superblock. > > > > Do I have a legitimate concern?? > > Your recipe is perfect. You need not be concerned. > > You are *not* changing the size of the partition underlying the RAID1 > array. When you change the size of a partition, it is not part of the > array at that time. It has no superblock on it, so there is no room > to be confused. > > If you were to make a small partition on the new sdb, add that to the > array, then change the partition table to make sdb1 bigger, that would > cause confusion. > However as you are making sdb1 nice and be before including it in the > array, everything should work perfectly. > > The only possible problem area in your recipe is if the drives are not > actually identical (not all 750GB drive have the same number of > blocks), the array you get with the -G command might be too big to > allow the partition you create on the new sda. However if the drives > do have exactly the same number of sectors, this will not be a problem. > > NeilBrown Thanks, I see the distinction now. Russ -- 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
