From owner-freebsd-questions Fri Dec 6 6:43: 1 2002 Delivered-To: freebsd-questions@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id E7DF837B404 for ; Fri, 6 Dec 2002 06:42:59 -0800 (PST) Received: from Thanatos.Shenton.Org (chris.shenton.org [209.31.144.77]) by mx1.FreeBSD.org (Postfix) with SMTP id E91B143EB2 for ; Fri, 6 Dec 2002 06:42:52 -0800 (PST) (envelope-from chris@Shenton.Org) Received: (qmail 56469 invoked by uid 1000); 6 Dec 2002 14:42:42 -0000 To: questions@freebsd.org Cc: hardware@freebsd.org Subject: amr AMI MegaRAID IDE card: "spare" drive as slave? From: Chris Shenton Date: Fri, 06 Dec 2002 09:42:42 -0500 Message-ID: <87isy79pjx.fsf@thanatos.shenton.org> User-Agent: Gnus/5.090008 (Oort Gnus v0.08) Emacs/21.2 (i386--freebsd) MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Sender: owner-freebsd-questions@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.ORG I have an AMI MegaRAID sold by Dell as a CERC ATA100; it has 4 discreet channels of IDE and can do RAID 0, 1, 5, or 10. I've been running it as RAID 1 for a couple months no problem, with a pair of WD1200JB 120G disks and a pair of 20G disks -- two logical partitions. The man page only talks about the amr driver for SCSI so I'm guessing that the interface to the computer looks identical to the AMI SCSI cards, but the disk interface is simply IDE. chris@pectopah_34% dmesg|grep am amr0: mem 0xfeb00000-0xfeb0ffff irq 5 at device 4.0 on pci0 amr0: Firmware 6.61, BIOS 1.01, 16MB RAM amrd0: on amr0 amrd0: 19068MB (39051264 sectors) RAID 1 (optimal) amrd1: on amr0 amrd1: 114428MB (234348544 sectors) RAID 1 (optimal) Mounting root from ufs:/dev/amrd0s1a For performance, naturally each disk is an IDE master on its own IDE cable. I'd like to get another disk or two and use them as hot spares so if one of the existing drives goes bad the amr controller can just rebuild the data on the spare. Can such a spare run as the IDE channel slave without impacting performance of the master? My thinking is that the controller should send no data to the slave unless the master dies so it shouldn't slow the master (and hence the RAID volume) but I don't know enough about how this hardware works. Any info would be most helpful. Thanks. To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-questions" in the body of the message