This might be a case of 'well you asked for it', but maybe the system
could be mmore friendly :-)

When a disk write is done, the offset of the partition on the disk is
taken from the CURRENT disklabel, not the label that existed at the time
the partition was mounted.

There are no checks to stop you changing the partition offsets of a
partition that has a filesystem mounted on it.  However changing these
values will be rather devastating on the disk area that the label now
points to.

IMHO the mount should grab the current offset and stick with it.

I've been trying to write the label for my second netBSD boot on the
same disk! (in order to be able to use the bootselector to pick which
partitio to boot.)  Fortunately I've trashed the 'current' partition
(which is relatively easy to recreate) not the main one.

Actually I think I have installed the correct label - just as I trashed
the FS...

	David