Re: Block-level CRC checks - Mailing list pgsql-hackers

From Kevin Grittner
Subject Re: Block-level CRC checks
Date
Msg-id 48E3865E.EE98.0025.0@wicourts.gov
Whole thread Raw
In response to Re: Block-level CRC checks  (Tom Lane <tgl@sss.pgh.pa.us>)
Responses Re: Block-level CRC checks
List pgsql-hackers
>>> Tom Lane <tgl@sss.pgh.pa.us> wrote: 
> Paul Schlie <schlie@comcast.net> writes:
>> - yes, if you're willing to compute true CRC's as opposed to
simpler
>> checksums, which may be worth the price if in fact many/most data
>> check failures are truly caused by single bit errors somewhere in
the
>> chain,
> 
> FWIW, not one of the corrupted-data problems I've investigated has
ever
> looked like a single-bit error.  So the theoretical basis for using
a
> CRC here seems pretty weak.  I doubt we'd even consider automatic
repair
> attempts anyway.
+1
The only single-bit errors I've seen have been the result of a buggy
driver for a particular model of network card.  The problem went away
with the next update of the driver.  I've never encountered a
single-bit error in a disk sector.
-Kevin


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