[comp.os.vms] THE DUMP file

STEINBERGER@KL.SRI.COM (Richard Steinberger) (12/24/87)

There is a dump file on my system disk that is 32767 blocks large (the
same size as physical memory).  My understanding is that this area will
be used by VMS in case the system crashes.  The contents of memory will 
be stored here.  This is fine; but I was wondering if there are any ways
to have this file/disk area serve two functions since it seems to be
unused during "normal" VMS operations.  For example, is there a way that
it can also be a page or swap file until/unless the system crashes? 
Are there other uses or should I just keep my hands off?  Thanks
in advance to all who respond.

-Ric Steinberger

-------

dp@JASPER.Palladian.COM (Jeffrey Del Papa) (12/24/87)

    Date: Wed 23 Dec 87 09:49:46-PST
    From: Richard Steinberger <STEINBERGER@KL.SRI.COM>

    There is a dump file on my system disk that is 32767 blocks large (the
    same size as physical memory).  My understanding is that this area will
    be used by VMS in case the system crashes.  The contents of memory will 
    be stored here.  This is fine; but I was wondering if there are any ways
    to have this file/disk area serve two functions since it seems to be
    unused during "normal" VMS operations.  For example, is there a way that
    it can also be a page or swap file until/unless the system crashes? 
    Are there other uses or should I just keep my hands off?  Thanks
    in advance to all who respond.

    -Ric Steinberger

    -------

first off, the file hase to be physical memory size plus 3 (to allow preserving
the internal processor registers)

leave well enought alone, as you would have to manually install the file after
every startup - if you auto installed it, the system would come up, and start
paging over your now quite valuable crash dump.

<dp>

rde@eagle.ukc.ac.uk (R.D.Eager) (12/25/87)

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You can't really use the dump file for anything else...but you can use the
page file as a dump file (sort of). See the System Management Guide for
more details. Snag is you have to read the dump out of the page file on
system startup to 'unlock' the space it used; but that can be made routine.
-- 
           Bob Eager
           rde@ukc.UUCP
           ...!mcvax!ukc!rde
           Phone: +44 227 764000 ext 7589

hydrovax@nmtsun.nmt.edu (M. Warner Losh) (12/27/87)

We reciently deleted our sysdump.sys file.  Strange things have been happening
ever since then.  I don't know if it is a hardware problem or what, but here
goes:

	When we bring down the system, we find that when we come back
up, that about 50 files have been stepped on.  These almost always
occur in certain user's accounts (No, I KNOW that it isn't these
user's doing it.  It IS something else.)  I wonder if it has anything
to do with the Dump file.  We have a Double Eagle (Fuji) with an Emulex
QD33 (or maybe 32) controller.  Is this a hardware problem, or something
that is connected to my blowing the sysdump.dmp (or what ever it is called,
the exact name escapes me right now...)???

		Confused in Socorro,

		Warner Losh


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