From: Alan Cox <alan@lxorguk.ukuu.org.uk>
To: "Jeff V. Merkey" <jmerkey@wolfmountaingroup.com>
Cc: Max Waterman <davidmaxwaterman@fastmail.co.uk>,
linux-kernel@vger.kernel.org
Subject: Re: io performance...
Date: Wed, 18 Jan 2006 09:21:04 +0000 [thread overview]
Message-ID: <1137576064.25819.11.camel@localhost.localdomain> (raw)
In-Reply-To: <43CDC44E.6080808@wolfmountaingroup.com>
On Maw, 2006-01-17 at 21:30 -0700, Jeff V. Merkey wrote:
> > How can I force it to be 'write back'?
> Forcing write back is a very bad idea unless you have a battery backed
> up RAID controller.
Not always. If you have a cache flush command and the OS knows about
using it, or if you don't care if the data gets lost over a power
failure (eg /tmp and swap) it makes sense to force it.
The raid controller drivers that fake scsi don't always fake enough of
scsi to report that they support cache flushes and the like. That
doesn't mean the controller itself is neccessarily doing one thing or
the other.
next prev parent reply other threads:[~2006-01-18 9:21 UTC|newest]
Thread overview: 30+ messages / expand[flat|nested] mbox.gz Atom feed top
2006-01-16 7:35 io performance Max Waterman
2006-01-16 7:32 ` Jeff V. Merkey
2006-01-17 13:57 ` Jens Axboe
2006-01-17 19:17 ` Jeff V. Merkey
2006-01-16 8:35 ` Pekka Enberg
2006-01-17 17:06 ` Phillip Susi
2006-01-18 7:24 ` Max Waterman
2006-01-18 15:19 ` Phillip Susi
2006-01-20 5:58 ` Max Waterman
2006-01-20 13:42 ` Ian Soboroff
2006-01-25 6:36 ` Max Waterman
2006-01-25 14:19 ` Ian Soboroff
2006-01-25 13:09 ` Bernd Eckenfels
2006-01-18 3:02 ` Max Waterman
2006-01-18 4:30 ` Jeff V. Merkey
2006-01-18 5:09 ` Max Waterman
2006-01-18 4:37 ` Jeff V. Merkey
2006-01-18 7:06 ` Max Waterman
2006-01-18 9:21 ` Alan Cox [this message]
2006-01-18 15:48 ` Phillip Susi
2006-01-18 16:25 ` Bartlomiej Zolnierkiewicz
2006-01-19 0:48 ` Adrian Bunk
2006-01-19 13:18 ` Max Waterman
[not found] <5vx8f-1Al-21@gated-at.bofh.it>
[not found] ` <5wbRY-3cF-3@gated-at.bofh.it>
[not found] ` <5wdKh-5wF-15@gated-at.bofh.it>
2006-01-19 1:58 ` Robert Hancock
2006-01-19 13:14 ` Max Waterman
2006-01-19 14:08 ` Alan Cox
2006-01-20 4:09 ` Max Waterman
2006-01-20 4:27 ` Alexander Samad
2006-01-20 12:52 ` Alan Cox
-- strict thread matches above, loose matches on Subject: below --
2006-01-19 11:39 Al Boldi
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