> ok, thanks to the numerous help, we're making progress with my second
> Hard disk.
> 
> running disklabel sd1, i found to have a "netbsd 4.2" on slice "a".
> 
> i set up fstab just like for the internal HD, trying to mount it in
> "/" (can I mount 2 roots?) one time as "ufs" the other one as "ffs".

No, you can't mount two roots. You'll confuse the system greatly.
Why would you want to do this? The traditional thing to do is mount
other patitions over top-level directories, though you can do what
ever you like.

I'm in the habit of mounting things on /y1, /y2, ...

Take care,

Bill