Date: Fri, 13 Jul 2001 18:28:02 -0700 From: Cy Schubert - ITSD Open Systems Group <Cy.Schubert@uumail.gov.bc.ca> To: "Albert D. Cahalan" <acahalan@cs.uml.edu> Cc: freebsd-stable@FreeBSD.ORG, jfortin@akalink.com Subject: Re: Regarding New FreeBSD BenchMark From Sysadmin Mag (left out a fiew tuning options) Message-ID: <200107140128.f6E1Stx06358@cwsys.cwsent.com> In-Reply-To: Your message of "Thu, 12 Jul 2001 22:05:00 EDT." <200107130205.f6D250Y136048@saturn.cs.uml.edu>
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In message <200107130205.f6D250Y136048@saturn.cs.uml.edu>, "Albert D. Cahalan" writes: > > Jonathan Fortin writes: > > > It is regarding the new benchmark (FreeBSD-tuned), > > > > They forgot to enable write-cache behind (enabled by default in windows2000 > > and linux) and a bit other options I would liked of seened. > > > > hw.ata.wc = 1 > > That is for ATA. They used SCSI. > SCSI write back cache is enabled in the drive's firmware. Linux and Windows enable it by default To enable SCSI write back cache you'll need to edit the WCE (Write Cache Enable) bit in modepage 0x08, camcontrol modepage da0 -m 0x08 -e -P 3 You will be entered into a vi session. Change the WCE value from 0 to 1 to enable write back cache and save. Once set, the drive will remember the value across reboots and power cycles. I suppose there might be some way to automate this through a camcontrol cmd command. Alternatively you can install the SCSI drive on a Linux or NT system first. Both will enable WCE from the get go. Then install the drive on a FreeBSD system. Some SCSI drive manufacturers ship their drives with WCE enabled. Other SCSI drive manufacturers, who are more concerned with data integrity as opposed to performance figures, will ship their drives with WCE disabled. The default your drive will be shipped with depends on the drive's manufacturer. Regards, Phone: (250)387-8437 Cy Schubert Fax: (250)387-5766 Team Leader, Sun/Alpha Team Internet: Cy.Schubert@osg.gov.bc.ca Open Systems Group, ITSD, ISTA Province of BC To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-stable" in the body of the message
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