Building AIX 3.1 instupdt preload trees

[R. Lindsay Todd]

Hello -- I have been trying, with partial success, to build preload trees,
like /usr/sys/preload, suitable for instupdt.  This is necessary since
we have one file server with a 8mm tape drive that can read our update
tapes and a growing number of tapeless client 320's.

Is there some AIX utility I've missed that can maintain preload structures,
so that I can just read in a tape and it will pick appropriate names for
each file as well as update the table of contents (.toc) file, and even
purge out old updates?  Has anyone written such a utility if IBM hasn't?
I've looked on the CD-ROM for this (bffcreate doesn't seem to be the right
approach).  I've also looked for some documentation on what goes on an update
tape (I know that file 3 is .toc, and that updates follow; what else is on
the tape?), but can't find any.  Nor do I see a description of .toc (which is
why my hand-built preload trees don't always work well).  Anybody have some
more information they can offer?
--
R. Lindsay Todd, Systems Programmer
ECS, Rensselaer Polytechnic Institute, Troy, NY 12180-3590
Internet: todd at narnia.ecs.rpi.edu