From owner-freebsd-scsi Mon May 15 8:41: 1 2000 Delivered-To: freebsd-scsi@freebsd.org Received: from mx1.quantum.com (mx1.quantum.com [204.212.103.34]) by hub.freebsd.org (Postfix) with ESMTP id 4D1E337B9D4 for ; Mon, 15 May 2000 08:40:58 -0700 (PDT) (envelope-from Stephen.Byan@quantum.com) Received: from milcmima.qntm.com (milcmima.qntm.com [146.174.18.61]) by mx1.quantum.com (8.9.3 (PHNE_18979)/8.9.3) with ESMTP id IAA26015; Mon, 15 May 2000 08:40:51 -0700 (PDT) Received: by milcmima.qntm.com with Internet Mail Service (5.5.2650.10) id ; Mon, 15 May 2000 08:40:50 -0700 Message-ID: <8133266FE373D11190CD00805FA768BF02EE9FA8@shrcmsg1.tdh.qntm.com> From: Stephen Byan To: "'Ian Cartwright'" , "'freebsd-scsi@freebsd.org'" Subject: RE: SCSI Speeds? Date: Mon, 15 May 2000 08:40:46 -0700 MIME-Version: 1.0 X-Mailer: Internet Mail Service (5.5.2650.10) Content-Type: text/plain; charset="iso-8859-1" Sender: owner-freebsd-scsi@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.org Just guessing, but I suspect it's because the IDE drives are caching writes, while the SCSI drives are not. Try enabling write-caching on the SCSI drives. Unfortunately, this will expose a data integrity risk in the event of a power failure (you are already exposed to this risk on your IDE drives). fsck may not be able to unscramble the file system, since some of the synchronous writes of UFS meta-data may not have made it to the disk media before the power fail. I don't recommend enabling write-caching for drives holding UFS file systems unless you have an uninterruptible power supply on the system and the drives. Perhaps the I/O subsystem will someday be educated to selectively disable write-caching on UFS metadata writes, but until then, beware of enabling write-caching. Regards, -Steve Byan - not speaking for Quantum Corp. To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-scsi" in the body of the message