🚀 go-pugleaf

I'd never really given much time to think about the benefits of parity
checking of RAM, but this afternoon I have come home to find that my 3/80
had self-rebooted at 17:19 when the kernel detected a parity error. I'll
let the log file speak for itself.... 

Jul 10 17:19:57 ppt vmunix: Parity error:
Jul 10 17:19:57 ppt vmunix: 	virtual address 0xffb6b750
Jul 10 17:19:57 ppt vmunix: 	errreg 0xd1	    
Jul 10 17:19:57 ppt vmunix: 	physical address 0x27d750
Jul 10 17:19:57 ppt vmunix: Parity error at SIMM U0603
Jul 10 17:19:57 ppt vmunix: panic:  synchronous parity error - kernel
Jul 10 17:19:57 ppt vmunix: syncing file systems... done
Jul 10 17:19:57 ppt vmunix: 00150 low-memory static kernel pages
Jul 10 17:19:57 ppt vmunix: 00144 additional static and sysmap kernel pages
Jul 10 17:19:57 ppt vmunix: 00000 dynamic kernel data pages
Jul 10 17:19:57 ppt vmunix: 00025 additional user structure pages
Jul 10 17:19:57 ppt vmunix: 00001 segmap kernel pages
Jul 10 17:19:57 ppt vmunix: 00000 segvn kernel pages
Jul 10 17:19:57 ppt vmunix: 00184 current user process pages
Jul 10 17:19:57 ppt vmunix: 00022 user stack pages
Jul 10 17:19:57 ppt vmunix: 00526 total pages (526 chunks)
Jul 10 17:19:57 ppt vmunix: 
Jul 10 17:19:57 ppt vmunix: dumping to vp ff1a7214, offset 33136
Jul 10 17:19:57 ppt vmunix: 526 total pages, dump succeeded
Jul 10 17:19:57 ppt vmunix: rebooting...
Jul 10 17:19:57 ppt vmunix: SunOS Release 4.1.1 (sun3x_80) #2: Sun Jan 22 12:11:09 EST 1995

I never knew that the kernel logged not only the location details but also
the number of the RAM module as shown on the 3/80 schematic! 

Anyway, I'm a little confused as to how this error was actually detected,
and since it hasn't occured again would I be right to assume that it might
have been a random thing and not a *real* RAM problem? I was under the
impression that RAM integrity checking was only ever done as part of the
power-on self test. 

Regards,

Craig.
-- 
     Craig Dewick, located in Sydney, Australia. cdewick@orb.apana.org.au
      Phone: [PSTN] (int. +612, loc. 02)-527-1292, or [GSM] 0411-158-574
 Always striving for a secure long-term future in an insecure short-term world
    "But wait, there's more..." - "Don't send any money, we'll bill you..."