Archiving II

[Eric Dean Tribble <tribble>]

retrievable/believeable copy - make a copy that the backend
	   knows how to get ahold of.

   Maybe "knows how to get ahold of" is too strong in some cases?  If
   it got saved on tape, the backend can't be sure it can find it
   again.  Maybe you just want to say "has a name for" or "knows how
   to ask for?"

Anyone should be able to give the backend a name for any believeable
copy.  A retrievable copy is a tape that the backend can assume that
it has access to:  it can ask the sysAdmin to mount the tape and load
documents from it.  This is necessary so that everything on the tape
can be considered 'clean' wrt purging from the disk.

   This is presumably implemented with the standard xanadu region
   transformation stuff?  You don't want to run around adjusting a
   lot of escalators when you can just add a multiplier between
   them and the pool to reduce their share.  (I assume you thought
   of this already.)

Definitely.  The mechanism we have in mind is somewhat different, but
we've thought about that concern.

dean