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Date: Thu, 27 Apr 2006 08:57:51 -0400
Subject: Re: Running on an NFS Mounted Directory
From: Ketema Harris <ketema@gmail.com>
To: Michael Stone <mstone+postgres@mathom.us>
CC: <pgsql-performance@postgresql.org>
Message-ID: <C076380F.2CEA%ketema@gmail.com>
Thread-Topic: [PERFORM] Running on an NFS Mounted Directory
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In-Reply-To: <20060427124455.GF31328@mathom.us>
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OK.  My thought process was that having non local storage as say a big raid
5 san ( I am talking 5 TB with expansion capability up to 10 ) would allow
me to have redundancy, expandability, and hopefully still retain decent
performance from the db.  I also would hopefully then not have to do
periodic backups from the db server to some other type of storage.  Is this
not a good idea?  How bad of a performance hit are we talking about?  Also,
in regards to the commit data integrity, as far as the db is concerned once
the data is sent to the san or nas isn't it "written"?  The storage may have
that write in cache, but from my reading and understanding of how these
various storage devices work that is how they keep up performance.  I would
expect my bottleneck if any to be the actual Ethernet transfer to the
storage, and I am going to try and compensate for that with a full gigabit
backbone.


On 4/27/06 8:44 AM, "Michael Stone" <mstone+postgres@mathom.us> wrote:

> On Thu, Apr 27, 2006 at 08:38:55AM -0400, Ketema Harris wrote:
>> I am looking for the best solution to have a large amount of disk storage
>> attached to my PostgreSQL 8.1 server.
> 
>> What other options/protocols are there to get high performance and data
>> integrity while having the benefit of not having the physical storage
>> attached to the db server?
> 
> These are two distinct requirements. Are both really requirements or is
> one "nice to have"? The "best" solution for "a large amount of disk
> storage" isn't "not having the physical storage attached to the db
> server". If you use non-local storage it will be slower and more
> expensive, quite likely by a large margin. There may be other advantages
> to doing so, but you haven't mentioned any of those as requirements.
> 
> Mike Stone