[Zope-dev] Re: Data.fs corruption when creating lots of objects.

R. David Murray bitz@bitdance.com
Tue, 9 May 2000 00:18:04 -0400 (EDT)


The cause of the database corruption that I was observing has, with a
fair degree of certainty, been identified, and I can sum it up in
one word:

hardware

The server on which I was doing the load apparently has a really
subtle bug where it will randomly and only occasionally write a
single bad byte to disk.  So a large database load had a high
probability of getting hit.  I began to suspect this when I discovered
that various system binaries (the date command, lynx) were failing
with odd error messages (bad syscall, for example).  Yet the system
mostly ran just fine...

I redid the database load on new hardware, and things have been working
perfectly.

(Can you imagine what would have happened had this hardware been used
for its usual market:  Windows or NT?  I could realize this was hardware
because system binaries in FreeBSD just don't fail like that.  But
if it were Windows, one would doubtless just reinstall, and the problem
would go away, only to crop up in some *other* binary later...)

I'm very relieved to be able to report that I have *not* found
a data corruption problem with the ZODB!!

--RDM