From: Tom Lane <tgl@sss.pgh.pa.us>
To: John A Meinel <john@arbash-meinel.com>
Cc: KeithW@narrowpathinc.com, PostgreSQL Perform <pgsql-performance@postgresql.org>
Subject: Re: Moving pg_xlog
Date: Thu, 02 Jun 2005 02:06:31 -0400
Message-ID: <10259.1117692391@sss.pgh.pa.us> (raw)
In-Reply-To: <429E2854.1050209@arbash-meinel.com>
References: <20050601151618.M48325@narrowpathinc.com>
<14825.1117642780@sss.pgh.pa.us>
<20050601200610.M12354@narrowpathinc.com>
<18210.1117657854@sss.pgh.pa.us>
<429E2854.1050209@arbash-meinel.com>
John A Meinel <john@arbash-meinel.com> writes:
> Tom Lane wrote:
>> Now that I think about it, you were (if I understood your layout
>> correctly) proposing to put the xlog on your system's root disk.
>> This is probably a bad idea for performance, ...
> I certainly agree with what you wrote. But my understanding is that if
> you only have 2 arrays, then moving xlog onto the array not on the
> database is better than having it with the database. It isn't optimum,
> but it is better. Because that way there isn't as much contention
> between the database and xlog.
If the machine isn't doing much else than running the database, then
yeah, that may be the best available option. If there are other things
going on then you have to think about how much competition there is for
the root disk.
But the impression I had from the OP's df listing is that he has several
disks available ... so he ought to be able to find one that doesn't need
to do anything except xlog.
regards, tom lane
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To: pgsql-performance@postgresql.org
Cc: tgl@sss.pgh.pa.us, john@arbash-meinel.com
Subject: Re: Moving pg_xlog
In-Reply-To: <10259.1117692391@sss.pgh.pa.us>
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