Converting between ext2 and ext3

ext2 to ext3:

 umount /dev/sda9
 tune2fs -j /dev/sda9
 fsck.ext3 -f /dev/sda9
 mount -t ext3 /dev/sda9

ext3 to ext2:

 umount /dev/sda9
 tune2fs -O ^has_journal /dev/sda9
 fsck.ext2 -f /dev/sda9
 mount -t ext3 /dev/sda9