Date: Wed, 7 Mar 2001 18:28:50 -0800 From: "Philip J. Koenig" <pjklist@ekahuna.com> To: Questions@FreeBSD.ORG Subject: Re: SoftUpdates/hardware write cache Message-ID: <3AA67DE2.28231.1BD305F@localhost> In-Reply-To: <15014.59669.718668.654739@guru.mired.org> References: <123006805@toto.iv>
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On 7 Mar 2001, at 20:06, Mike Meyer boldly uttered: > Philip J. Koenig <pjklist@ekahuna.com> types: > > Apparently the new drive has the internal write cache turned off by > > default. I'm about to enable SoftUpdates with the tunefs thing and I > > was wondering if I should also enable the disk's internal write > > cache. My experience in the past with other OS's says it can make a > > big performance improvement. > > Generally, this isn't recommended. Soft updates *depend* on the device > actually having written the data to disk when it claims it has, and in > the order it specified. > > > This machine runs on a large UPS so power-loss isn't a big issue. > > Well, if you want to try it, go ahead. If you have the time, I'd be > interested in timings for all four cases (softupdates yes/no, write > cache yes/no). What benchmark and settings would be most helpful? I've got iozone-3.9 and bonnie-1.0 installed on this system. > > I know there is some Unix program that can at least read mode pages, > > I'm hoping it can set them too. My DOS program won't work on this > > hardware and I'd hate to have to stick the drive on a Windows machine > > to set that setting. :-) > > Camcontrol can do that for your scsi devices. Thanks - I remember that command now. Phil -- Philip J. Koenig pjklist@ekahuna.com Electric Kahuna Systems -- Computers & Communications for the New Millenium To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-questions" in the body of the message
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