Subject: Re: Postgres fsync off (not needed) with NetApp
From: Mark Lewis <mark.lewis@mir3.com>
To: Dan Gorman <dgorman@hi5.com>
Cc: pgsql-performance@postgresql.org
In-Reply-To: <9A377C54-361D-4F01-BF7A-7632FBA3453C@hi5.com>
References: <9A377C54-361D-4F01-BF7A-7632FBA3453C@hi5.com>
Content-Type: text/plain
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Organization: MIR3, Inc.
Date: Wed, 14 Jun 2006 14:54:45 -0700
Message-Id: <1150322085.31200.39.camel@archimedes>
Mime-Version: 1.0

No.  You need fsync on in order to force the data to get TO the NetApp
at the right time.  With fsync off, the data gets cached in the
operating system.

-- Mark Lewis

On Wed, 2006-06-14 at 14:48 -0700, Dan Gorman wrote:
> All,
>    So I thought I'd pose this question:
> 
> If I have a pg database attached to a powervault (PV) with just an  
> off-the-shelf SCSI card I generally want fsync on to prevent data  
> corruption in case the PV should loose power.
> However, if I have it attached to a NetApp that ensures data writes  
> to via the NVRAM can I safely turn fsync off to gain additional  
> performance?
> 
> Best Regards,
> Dan Gorman
> 
> 
> 
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