From: Fred Kleinsorge [nospam@please.com]
Sent: Friday, December 17, 1999 11:07 AM
To: Info-VAX@Mvb.Saic.Com
Subject: Re: Consequences of raising MAXBOBMEM for EXBUFOBJLM errors

MAXBOBMEM was invented to prevent someone consuming all physical memory by
placing a system wide limit on physical memory consumption by Buffer
Objects.

Because of the way some database applications work, MAXBOBS0S1 and S2 were
created to put similar limits on Virtual Address space (as opposed to
physical memory).

The DECwindows errrors that are "normally" seen come from the
X11 server, not from DECterm (for instance, the 3D30/4D20).  The failures do
NOT prevent operation -- because the code simply then uses PIO instead of
DMA.  The Buffer Object prevents the need for doing lots of lock/unlocks for
DMA.

If you get the error for DECwindows, just crank up MAXBOBMEM *and*
MAXBOBS0S1 -- there is NO WAY TO DISTINGUISH A
FAILURE OF ANY OF THE THREE.  DECwindows does not use
S2 space.

In the NEXT release of OpenVMS, these parameters GO AWAY.
The exec group has determined that other mechanisms adequately
protect the system resource usage, and these limits simply get in
the way of proper operation.