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Date: Tue, 3 Nov 2009 12:19:20 +0100
From: Emmanuel Florac <eflorac@intellique.com>
Subject: Re: XFS and DPX files
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To: Michael Monnerie <michael.monnerie@is.it-management.at>
Cc: xfs@oss.sgi.com

Le Mon, 2 Nov 2009 22:58:35 +0100
Michael Monnerie <michael.monnerie@is.it-management.at> =E9crivait:

> Hence my suggestion for turning on the disk write cache just to see
> if it makes a difference.

Unfortunately there isn't any way in the 3Ware controllers to manage
that. Worse, I couldn't get a clear answer from 3Ware support about the
controller policy about drives caches. However from the tests I've done
(pulling the plug on a server while writing) it looks like the 3Ware
uses the disks caches in write-thru mode, however (fortunately now that
many drives come with 32 or 64 MB caches). =


Some other SATA/SAS RAID controllers (Areca, LSI and Adaptec) allows to
activate drive write-back cache separately from the controller cache,
though.

-- =

------------------------------------------------------------------------
Emmanuel Florac     |   Intellique
------------------------------------------------------------------------

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