4.8 panic "ffs_clusteralloc: map mismatch"
Avleen Vig
lists-freebsd at silverwraith.com
Wed Jul 16 05:57:46 PDT 2003
> I have been experiencing several "ffs_clusteralloc: map mismatch"
> kernel panics (always while heavy r/w activity on ad0). PC in question
> has SuperMicro P3TDL3 motherboard,
> 2 ide + 1 scsi HDD and 4 nics (full dmesg & kernel config attached).
Andrew,
I spend about two to three years fighting with a system trying to figure
out what was wrong, and why these errors were caused. I got the very
same crashes you're seeing now.
I'm sure others are too, and I think this reply would be useful for the
archives.
My Solution:
I eventually realised that my problem was with one of three things:
1) bit flips in main memory
2) bit flips in cache
3) bad hard drive
I replaced all of the memory after a few months. The problems stopped
for a few weeks but quickly returned. So I don't think it was main
memory, unless the new set or the sockets were damaged.
I couldn't replace the cache because I couldn't find any more. The
system was an old P1 (originally 75Mhz). This could have been the
problem.
I did once try turning off L2 cache in the BIOS, and I think the crashes
*might* have continued. So it's possible the problems were here.
Finally I didn't replace the hard drive, but I did find that moving load
off the original drive to a second drive helpped reduce the number of
crashes, although they still continued to happen.
HTH.
--
Avleen Vig "Say no to cheese-eating surrender-monkeys"
Systems Admin "Fast, Good, Cheap. Pick any two."
www.silverwraith.com "Move BSD. For great justice!"
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