Re: Crash while recovering database index relation

Guy Thornley <guy(at)esphion(dot)com> writes:
> On one of our test boxen here, weve experienced a corrupted file during
> database recovery after box power outage. The specific error message is
> PANIC: invalid page header in block 6 of relation "17792"
> This was on postgres 7.4.

I believe this is fixed in 7.4.1:

2003-12-01 11:53 tgl

* src/backend/storage/buffer/: bufmgr.c (REL7_3_STABLE), bufmgr.c
(REL7_4_STABLE), bufmgr.c: Force zero_damaged_pages to be
effectively ON during recovery from WAL, since there is no need to
worry about damaged pages when we are going to overwrite them
anyway from the WAL. Per recent discussion.

> By using postgres single-user database server and zero_damaged_pages option
> I manged to get the database up again. There were a LOT of relations with
> this problem !

And no sign of corruption after you'd run through the recovery with
zero_damaged_pages? That's what I'd expect if this scenario applies:
the pages will be fixed by WAL recovery, it's just that the recently
added check for broken page headers was interfering :-(

regards, tom lane