From: Bruce Momjian <pgman@candle.pha.pa.us>
To: Mark Kirkwood <markir@paradise.net.nz>
Cc: carlosreimer@terra.com.br, Mark Lewis <mark.lewis@mir3.com>
Cc: Tom Lane <tgl@sss.pgh.pa.us>
Cc: pgsql-performance@postgresql.org
Subject: Re: RES: Initial database loading and IDE x SCSI
Date: Sat, 3 Jun 2006 22:03:05 -0400 (EDT)
Message-ID: <200606040203.k54235c23743@candle.pha.pa.us> (raw)
In-Reply-To: <4480D427.50207@paradise.net.nz>
Mark Kirkwood wrote:
> Mark Lewis wrote:
>
> >
> > The naive approach works on IDE drives because they don't (usually)
> > honor the request to write the data immediately, so it can fill its
> > write cache up with several megabytes of data and write it out to the
> > disk at its leisure.
> >
>
> FWIW - If you are using MacOS X or Windows, then later SATA (in
> particular, not sure about older IDE) will honor the request to write
> immediately, even if the disk write cache is enabled.
>
> I believe that Linux 2.6+ and SATA II will also behave this way (I'm
> thinking that write barrier support *is* in 2.6 now - however you would
> be wise to follow up on the Linux kernel list if you want to be sure!)
>
> In these cases data integrity becomes similar to SCSI - however, unless
> you buy SATA specifically designed for a server type workload (e.g WD
> Raptor), then ATA/SATA tend to fail more quickly if used in this way
> (e.g. 24/7, hot/dusty environment etc).
The definitive guide to servers vs. desktop drives is:
http://www.seagate.com/content/docs/pdf/whitepaper/D2c_More_than_Interface_ATA_vs_SCSI_042003.pdf
--
Bruce Momjian http://candle.pha.pa.us
EnterpriseDB http://www.enterprisedb.com
+ If your life is a hard drive, Christ can be your backup. +
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To: pgsql-performance@postgresql.org
Cc: pgman@candle.pha.pa.us, markir@paradise.net.nz, mark.lewis@mir3.com, tgl@sss.pgh.pa.us
Subject: Re: RES: Initial database loading and IDE x SCSI
In-Reply-To: <200606040203.k54235c23743@candle.pha.pa.us>
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