Location of disklabel

[Carl J]

Hi all! To all your FS guru's outthere, I desperately need
to know where the disklabel is stored (since my disk is in trouble!)

Situation:

   My /dev/ad0s1 has 2 partitions: "a" (FS) followed by "b" (swap).
   By using "disklabel -r", I see my "a" and "b" indeed
   take up the entire slice.

My desperate question:

   Where, then, is the "disklabel" stored?

   Somewhere in the partition table? The Master Boot Record?
   The reserved cylinder #0?

   Or is it stored somewhere inside /dev/ad0s1a ??
   (if that's the case, does that mean the UFS1
   intentionally left some space unused, for this purpose?
   And if so, is it always at a fixed location within a UFS1 slice?)

   What if in my slice, I have SWAP first, and then UFS1,
   then does that mean the SWAP Format also reserves
   some unused space for the disklabel to go???

Sorry if the question is stupid. I just somehow couldn't
logically see where it would be stored, and yet be compatible
with having other OS on the same drive... etc.

Thanks!

- Carl