Re: Recommended optimisations slows down PostgreSQL 8.4 - Mailing list pgsql-performance

From Stephen Frost
Subject Re: Recommended optimisations slows down PostgreSQL 8.4
Date
Msg-id 20110812210742.GB12765@tamriel.snowman.net
Whole thread Raw
In response to Re: Recommended optimisations slows down PostgreSQL 8.4  (Waldo Nell <pwnell@telkomsa.net>)
List pgsql-performance
* Waldo Nell (pwnell@telkomsa.net) wrote:
> The fsync = off was because the production system runs on a uber expensive SAN system with multipathing over Fibre
Channel,it is on UPS and backup generators in a secure datacenter, and we have daily backups we can fall back to. 

So, two points: #1- the uber-expensive SAN should make twiddling fsync
have much less of an effect on performance than in a non-SAN/non-BBWC
environment, so you might validate that you really need it off.  #2- the
SAN, FC, UPS, etc will be of no help if the OS or PG crash.  Seems
pretty harsh to resort back to a daily backup in the event the OS reboots
due to some wacky NMI, or the ASR going haywire..

    Thanks,

        Stephen

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