Neil Brown <neilb@xxxxxxxxxxxxxxx> writes: > On Thursday August 4, neilb@xxxxxxxxxxxxxxx wrote: >> >> Oopps.... >> I meant to send the following in reply to a recent message from >> Gregory Seidman, but inadvertently send it in reply to an earlier >> message from Aaron Botsis (which I must have missed..) >> >> Still, the offer is open to either, or anyone else. > > I decided to try it anyway... > > The following patch, when applied to mdadm-2.0-devel-3 (Recently > released) should allow: > > mdadm --examine --metadata=0.swap /dev/sda1 > > which will show the superblock with bytes swapped. If that looks right for > all devices, then > > mdadm --assemble /dev/mdX --update=byteorder /dev/sda1 /dev/sdb1 ... > > will assemble the array after swapping the byte order on all devices. > Once it has been assembled this way, the superblocks will have the > correct byte order, and in future the array can be assembled in the > normal way. > > Feedback would be very welcome. If I read your notes correctly, it should be possible to determine that this is (or isn't) a byte-swapped v0 superblock by checking for the byte-swapped magic number, right? In that case, I think it would be good to have --update=byteorder refuse to work if that magic number check either wasn't the byte-swapped variant. Adding a 'force' or something to bypass the check if you *really* want to seems reasonable-ish. That would make it just that little bit harder to accidentally byte-swap a superblock when you shouldn't have done so. Daniel - 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
