grr@cbmvax.commodore.com (George Robbins) (01/17/90)
Ultrix 3.1
VAX 785
DH11 (Able)
Ever since installing Ultrix 3.x I've been been having problems with
my system crashing - sometimes every two or three days, occasisionally
two or three times a day. The crashes usually seemed to be related to
NFS activity and dumps often showed many running processes.
The crashes generally showed up as some form of corruption in the
kernal memory pool. Panics seen were km_alloc, segmentation fault,
protection fault and a couple other random ones. Most of the dumps
I analysed show the failure coming from something getting plugged
in the memory pool, the most memorable ones being the mbuf chain
pointers off of bucket+20 being decremented(!).
I turns out that the crashes are (apparently) closely linked to heavy
serial activity on the DH11 clone. I had two trailblazers in frequent
uucp use at 19200 buad on the I/F and when they both got into receive
mode "silo overruns" were frequent.
After moving the modems back to the DMF32's, I get lots more silo
overruns, but no crashes. I think it's a pretty good hint of either
a diseased DH11 or a problem with the (unsupported) DH11 driver.
I don't know if I'll get a chance to delve deeper - I'm working hard
to get users over to the new 5810 and the VAX is history by the end
of the month...
--
George Robbins - now working for, uucp: {uunet|pyramid|rutgers}!cbmvax!grr
but no way officially representing arpa: cbmvax!grr@uunet.uu.net
Commodore, Engineering Department fone: 215-431-9255 (only by moonlite)