odd zfs behaviour on reboot

[Pete French]

was just experimenting with zfs on a spare slice on the disc - this may all
be entirely my fault for doing it worng, if so please tell me, but I
appear to be gettign a zfs pool ounted on reboot but with none of the
data appearing in it!

what I did:

1) take a space slice, only got one partition on it being 'c' the whole disc
2) glabeled it as 'zfstest' so it appears in /dev/label/zfstest
3) create a pool with 'zpool create tank /dev/label/zfstest
4) create another file system on it as 'zfs create tank/newfs'
5) sprinkle some files into both directories

so thois gives me a /tank and a /tank/newfs, with some files in
them (there was no /tank director previously). I can zpool export and
zpool import the tank and it all works fine.

so then I reboot

...and after reboot I get /tank, but it is empty! a 'zpool status' tells
me that the pool is there and imported, but it doesnt show up when I
type 'mount'. If I do an export and import then all the files appear again
and the filesystem shows up in 'mount' though.

any ideas ? it is obviosuly finding the pool, but not mounting any of the
files systems from the looks of things.

-pete.