Overpushing the buffer while booting...

["P. T. Withington" <PTW@diamond.s4cc.symbolics.com>]

    Date: Tue, 24 Nov 87 09:45 EST
    From: James A. Reith Sr. <reith@MEAD.SCRC.Symbolics.COM>

	Date: Mon, 23 Nov 87 21:22 EST
	From: Robert W. Kerns <RWK@YUKON.SCRC.Symbolics.COM>

	    Date: Sat, 21 Nov 87 17:25 PST
	    From: Steve Trever <trev@VERMITHRAX.SCH.Symbolics.COM>

		Date: Sat, 21 Nov 87 19:05:01 EST
		From: John T. Nelson <jtn@potomac>
		Every other boot on our Symbolics 3670 generates either an "Overpushed
		buffer", or "FEP memory full" error and prevents us from booting our
		machine.  I suspect that either the "Find IDS Files" command or the
		flods we scan are causing FEP memory to fill up.  I've tried "Clear
		Command Tree" which clears the flod information out, but this doesn't
		help.  I've found that the only way to boot the machine after receiving
		this error is to do a reset FEP which is not a satisfactory solution
		since this spins the disks down and back up again.

	Why are you using Find IDS Files?  It shouldn't ordinarily be
	necessary to give this command.  Have you tried taking out
	this command from your boot file, and resetting the FEP, and
	seeing how things work?

    What I've found on systems with a lot of worlds is that if you use the
    nonspecific case it runs out of memory while checking the worlds on the
    disk and fails to find all the parents. If you Add IDS File the specific
    parents for the world you're trying to boot it will work properly. Some
    of this might also be fixed in the newer flod files. I've seen it mostly
    on "lotta worlds" stock 7.1 machines in the field. The Add IDS File
    <specific world> seems to help (as long as you remember to add in all
    the parents and change it when you layer on another IDS).

But he says he's using Find World Files, which the FEP will gladly do,
but its extra work for the FEP and, as Kerns notes, can only worsen the
problem.

Two things I don't believe I've seen mentioned yet in this discussion:

1) The FLODS that will be released with 7.2 have solved this problem in
all the cases I know of.

2) Use of "indirect" boot files severely exacerbates the problem on
earlier FLODS.  I.e., if you have a boot.boot that sets up some generic
things then invokes another boot file (using the Boot command) to load
the actual world.  Is it possible Nelson is using this technique?