[comp.sys.next] Summary: Help with memory error

scott@jgravesnext.nurs.utah.edu (Scott E. Greenman) (06/13/91)

Thanks to those who replied to my question.  My original post was:

> We recently upgraded one of our NeXT cubes from 16MB of memory to 40MB.  
> Everything has seemed to work okay since then, but I just noticed I'm getting 
> tons of errors in the /usr/adm/messages file.  This is the error I'm getting:
>
> Jun 10 10:35:14 jgravesnext mach: spurious DMA interrupt
> Jun 10 10:36:09 jgravesnext mach: Spurious DMA interrupt - state = 1000000 @ 
> 2000110
>
> It's repeated about once or twice an hour.  I haven't figured out if a single 
> program is causing it.  Does anyone have any ideas as to what could be wrong?

Here are the replies that I received:

From: bartont@next2.msci.memst.edu (Tom Barton)
> I have seen this error generated during periods when
> another machine's ethernet card was going bad, causing
> multiple collision errors on the ethernet for periods of
> time. This seems to be a NeXT manifestation of that
> network problem. To check if the cause is outside of your
> cube, try marking its ethernet interface as "down"
> (using the ifconfig command) for an hour or two and see if
> no more messages are generated during that time. If so,
> then get your network administrator on to the problem - he
> or she will have other ways of observing the problem, and
> other brands of machines are not always so graceful in the
> face of such problems. 
> -- 
> Tom Barton			       Internet: bartont@next2.msci.memst.edu
> Department of Math Sciences	         Bitnet: bartont@memstvx1
> Memphis State University	          Phone: 901-678-2527

From: grd@ccrma.stanford.edu
> My file server displays the same spurious DMA interrupt message,
> though not as often as yours (about once a day).  I'm submitting
> a bug report to next, and will let you know (if and when)
> they reply!
> 
> -glen
> grd@ccrma.stanford.edu

From: grd@ccrma.stanford.edu
> Here's NeXT's reply (only took 2 days!)...
> 
> Date: Tue, 11 Jun 91 14:00:28 PDT
> From: Eric_Larson@next.com
> To: grd@ccrma.Stanford.EDU
> Subject: Re: spurious dma interrupt
> 
> Hi Glen,
> 
> Regarding:
> 
> Jun  9 09:00:15 ccrma mach: Spurious DMA interrupt - state
> = 1000000 @ 2000110 Jun 10 07:02:09 ccrma mach: spurious
> DMA interrupt
> 
> Our experience indicates that these messages are
> usually the result of a noisy network or serial line (or
> bad cables, etc. in both cases).  You can relax about them
> unless you start getting "video wallpaper" on your
> monitor (or worse).  I suspect this won't happen.  In the
> event it does, contact us.
> 
> Regards,
> 
> Eric Larson NeXTedge Technical Support
> eric_larson@next.com 

--
Scott Greenman					Univ of Utah
Associate Programmer				College of Nursing
scott@jgravesnext.nurs.utah.edu