Re: Durability?

Emmanuel Cecchet <manu@frogthinker.org> writes:
> I got an error like this:

> ERROR:  xlog flush request 1/C121E998 is not satisfied --- flushed only to 1/BCBCB440
> CONTEXT:  writing block 529 of relation 1663/233690/1247
> WARNING:  could not write block 529 of 1663/233690/1247
> DETAIL:  Multiple failures --- write error might be permanent.

> The xrecoff value (logs show 1/xrecoff) advances a few times during the day, but the message keeps appearing.

It looks like you've got a corrupted page in shared buffers, and every
time the system tries to flush it to disk for a checkpoint, it fails.

What I'd try for getting out this is to kill -9 some backend in order
to force a database restart.  Of course, if you want to investigate
what caused it, you should dig around in shared memory first and try
to get a copy of that buffer's contents.
        regards, tom lane