Re: Block-level CRC checks

Simon Riggs wrote:
> On Tue, 2009-12-01 at 07:05 -0500, Bruce Momjian wrote:
> 
> > I assume torn pages are 99% of the reported problem, which are
> > expected and are fixed, and bad hardware 1%, quite the opposite of your
> > numbers above.
> 
> On what basis do you make that assumption?

Because we added full page write protection to fix the reported problem
of torn pages, which we had on occasion;  now we don't.  Bad hardware
reports are less frequent.

And we know we can reproduce torn pages by shutting of power to a server
without battery-backed cache.  We don't know how to produce I/O failures
on demand.

--  Bruce Momjian  <bruce@momjian.us>        http://momjian.us EnterpriseDB
http://enterprisedb.com
 + If your life is a hard drive, Christ can be your backup. +