On Tue, Sep 30, 2008 at 1:41 PM, Bruce Momjian <[EMAIL PROTECTED]> wrote:
> Alvaro Herrera wrote: > > A customer of ours has been having trouble with corrupted data for some > > time. Of course, we've almost always blamed hardware (and we've seen > > RAID controllers have their firmware upgraded, among other actions), but > > the useful thing to know is when corruption has happened, and where. > > > > So we've been tasked with adding CRCs to data files. > > Maybe a stupid question, but what I/O subsystems corrupt data and fail > to report it? Practically all of them. Here is a good paper on various checksums, their failure rates, and practical applications. "Parity Lost and Parity Regained" http://www.usenix.org/event/fast08/tech/full_papers/krioukov/krioukov_html/index.html -jwb
