On Mon, Sep 5, 2011 at 11:24 AM, Andres Freund <andres@anarazel.de> wrote:
> On Monday, September 05, 2011 14:57:43 Richard Shaw wrote:
>> Autovacuum has been disabled and set to run manually via cron during a quiet
>> period and fsync has recently been turned off to gauge any real world
>> performance increase, there is battery backup on the raid card providing
>> some level of resilience.
> That doesn't help you against a failure due to fsync() off as the BBU can only
> protect data that actually has been written to disk. Without fsync=on no
> guarantee about that exists.
Further, if you've got a bbu cache on the RAID card the gains from
fsync=off wll be low / nonexistent.