FFS snapshot on 5.0_STABLE pondering

["Martin S. Weber" <Ephaeton%gmx.net@localhost>]

Just a quick question: Is it intended behaviour for a snapshot created
on 5.0_STABLE via fssconfig that the directory hierarchy inside also
extends to the mounted directories beneath? Even without a changed
device id? There is nothing about that in the manpages.
How does it make a difference?

Say, e.g., you have /usr and /usr/src on different devices. Then
you create a snapshot of /usr and use pax -rw with the -X option 
on it. Or rsync -x ... expecting to NOT see </dev/fss0>/src contents
being transferred. Well. You WILL see src contents being transferred,
as obviously the usual "living on a different device" logic for pax,
rsync, find et al won't work on the mounted snapshot.

While at it: Is it normal that if you mount the snapshot it's unclean?
"/dev/fss0: file system not clean (fs_clean=0x4); please fsck(8)
 /dev/fss0: lost blocks 0 files 0"

Thanks for your input.

Regards,

-Martin