From: Jim C. Nasby <jnasby@pervasive.com>
To: Tino Wildenhain <tino@wildenhain.de>
Cc: Javier Somoza <jsomoza@pandasoftware.es>
Cc: pgsql-performance@postgresql.org
Subject: Re: fsync and battery-backed caches
Date: Mon, 27 Feb 2006 18:22:23 -0600
Message-ID: <20060228002223.GW82012@pervasive.com> (raw)
In-Reply-To: <4402D0A9.7080705@wildenhain.de>
References: <1141034594.1556.15.camel@pndsoft>
<4402D0A9.7080705@wildenhain.de>
On Mon, Feb 27, 2006 at 11:12:57AM +0100, Tino Wildenhain wrote:
> Javier Somoza schrieb:
> >
> > Hi all
> >
> > Is it secure to disable fsync havin battery-backed disk cache?
> >
> > Thx
> >
> No. fsync moves the data from OS memory cache to disk-adaptor
> cache which is required to benefit from battery backup.
More importantly, in guarantees that data is committed to non-volatile
storage in such a way that PostgreSQL can recover from a crash without
corruption.
If you have a battery-backed controller and turn on write caching you
shouldn't see much effect from fsync anyway.
--
Jim C. Nasby, Sr. Engineering Consultant jnasby@pervasive.com
Pervasive Software http://pervasive.com work: 512-231-6117
vcard: http://jim.nasby.net/pervasive.vcf cell: 512-569-9461
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To: pgsql-performance@postgresql.org
Cc: jnasby@pervasive.com, tino@wildenhain.de, jsomoza@pandasoftware.es
Subject: Re: fsync and battery-backed caches
In-Reply-To: <20060228002223.GW82012@pervasive.com>
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