From owner-freebsd-isp Mon Jun 14 11:46:18 1999 Delivered-To: freebsd-isp@freebsd.org Received: from aurora.sol.net (aurora.sol.net [206.55.65.76]) by hub.freebsd.org (Postfix) with ESMTP id 4C60C1547B for ; Mon, 14 Jun 1999 11:46:14 -0700 (PDT) (envelope-from jgreco@aurora.sol.net) Received: (from jgreco@localhost) by aurora.sol.net (8.9.2/8.9.2/SNNS-1.02) id NAA43719; Mon, 14 Jun 1999 13:46:06 -0500 (CDT) From: Joe Greco Message-Id: <199906141846.NAA43719@aurora.sol.net> Subject: Re: Hardware RAID for FreeBSD To: freebsd-isp@FreeBSD.ORG Date: Mon, 14 Jun 1999 13:46:01 -0500 (CDT) Cc: kpielorz@tdx.co.uk, rjebara@palnet.com X-Mailer: ELM [version 2.4ME+ PL43 (25)] MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-freebsd-isp@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.org > other than the DPT boards .. have you guys had any > success with other RAID controlers like Adaptec or AMI I was really disappointed with the performance I was getting out of the DPT. It was easy to saturate the poor thing. Further investigation suggests that this is probably because RAID parity calculation is done by the on-board CPU rather than by silicon. Under normal operation, I only need 1 or 2 MB/s writes, but being limited to not much more than that by the DPT would have been very irritating. SCSI-to-SCSI RAID controllers are nicer and the Mylex can be configured from the front panel (as opposed to something like the DPT SmartRAID IV which requires a DOS app). They appear to the OS as an actual storage device, rather than as a number of discrete drives. This means that you can install OS and stuff on them too, because the PC BIOS sees them as a single drive too. da1 at ahc0 bus 0 target 1 lun 0 da1: Fixed Direct Access SCSI-2 device da1: 40.000MB/s transfers (20.000MHz, offset 16, 16bit), Tagged Queueing Enabled da1: 61278MB (125497344 512 byte sectors: 255H 63S/T 7811C) CMD makes a smaller and I believe less expensive unit. If you are less into performance and simply need RAID5 ability, that may be the way to go... it is half-height too, as opposed to the full-height Mylex. However, the CMD unit has some performance limits (#tags, as I recall). The DAC960SX comes in a three-channel config (2 drive, 1 host) with 16MB cache for a bit more than $2K. ... Joe ------------------------------------------------------------------------------- Joe Greco - Systems Administrator jgreco@ns.sol.net Solaria Public Access UNIX - Milwaukee, WI 414/342-4847 To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-isp" in the body of the message