Re: checkpoint write errors

Thanks the REINDEX fixed it, it's a client of ours and we're pushing to
get them to move to 9.5



On 10/21/2016 06:33 PM, Tom Lane wrote:
> CS DBA <cs_dba@consistentstate.com> writes:
>> we're seeing the below errors over and over in the logs of one of our
>> postgres databases. Version 8.4.22
> [ you really oughta get off 8.4, but you knew that right? ]
>
>> Anyone have any thoughts on correcting/debugging it?
>> ERROR:  xlog flush request 2571/9C141530 is not satisfied --- flushed
>> only to 2570/DE61C290
>> CONTEXT:  writing block 4874 of relation base/1029860192/1029863651
>> WARNING:  could not write block 4874 of base/1029860192/1029863651
>> DETAIL:  Multiple failures --- write error might be permanent.
> Evidently the LSN in this block is wrong.  If it's an index, your idea of
> REINDEX is probably the best solution.  If it's a heap block, you could
> probably make the problem go away by performing an update that changes any
> tuple in this block.  It doesn't even need to be a committed update; that
> is, you could update or delete any row in that block, then roll back the
> transaction, and it'd still be fixed.
>
> Try to avoid shutting down the DB until you've fixed the problem,
> else you're looking at replay from whenever the last successful
> checkpoint was :-(
>
>> Maybe I need to run a REINDEX on whatever table equates to
>> "base/1029860192/1029863651"?  If so how do I determine the db and table
>> for "base/1029860192/1029863651"?
> 1029860192 is the OID of the database's pg_database row.
> 1029863651 is the relfilenode in the relation's pg_class row.
>
>             regards, tom lane