Re: [HACKERS] Re: PD_ALL_VISIBLE flag was incorrectly set happend during repeatable vacuum

Excerpts from daveg's message of mié mar 02 18:30:34 -0300 2011:

> After a restart and vacuum of all dbs with no other activity things were
> quiet for a couple hours and then we started seeing these PD_ALL_VISIBLE
> messages again.
>
> Going back through the logs we have been getting these since at least before
> mid January. Oddly, this only happens on four systems which are all new Dell
> 32 core Nehalem 512GB machines using iscsi partitions served off a Netapp.
> Our older 8 core 64GB hosts have never logged any of these errors. I'm not
> saying it is related to the hw, as these hosts are doing a lot more work than
> the old hosts so it may be a concurrency problem that just never came up at
> lower levels before.
>
> Postgresql version is 8.4.4.

I don't see how this could be related, but since you're running on NFS,
maybe it is, somehow:
http://archives.postgresql.org/message-id/4D40DDB7.1010000@credativ.com
(for example what if the visibility map fork's last page is overwritten?)

--
Álvaro Herrera <alvherre(at)commandprompt(dot)com>
The PostgreSQL Company - Command Prompt, Inc.
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