From owner-freebsd-hackers Sun Nov 11 3:23: 0 2001 Delivered-To: freebsd-hackers@freebsd.org Received: from freebsd.dk (fw-rl0.freebsd.dk [212.242.86.114]) by hub.freebsd.org (Postfix) with ESMTP id 21C9437B41C; Sun, 11 Nov 2001 03:22:54 -0800 (PST) Received: (from sos@localhost) by freebsd.dk (8.11.6/8.11.3) id fABBMqv25712; Sun, 11 Nov 2001 12:22:52 +0100 (CET) (envelope-from sos) From: Søren Schmidt Message-Id: <200111111122.fABBMqv25712@freebsd.dk> Subject: Re: HPT370 RAID or Vinum? In-Reply-To: <20011111110543.F31680@sydney.worldwide.lemis.com> To: Greg Lehey Date: Sun, 11 Nov 2001 12:22:52 +0100 (CET) Cc: Mike Smith , john_wilson100@excite.com, freebsd-hackers@FreeBSD.ORG, sos@FreeBSD.ORG Reply-To: sos@freebsd.dk X-Mailer: ELM [version 2.4ME+ PL94b (25)] MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Content-Type: text/plain; charset=ISO-8859-1 Sender: owner-freebsd-hackers@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.ORG It seems Greg Lehey wrote: > >> These "cheap controllers" don't have any algorithms at all to speak of; > >> they're just ATA controllers with BIOS code that supposedly understands > >> striping/mirroring. > > > > There is no algorithm to speak of involved with striping, and just > > a little more in mirroring in the error case, but anyways.. > > Well, there are questions of stripe size and whether you read entire > stripes or just the part you want. Sure, stripe size is not changeable to other sizes than the BIOS supports on the ATA RAID's or you wont be able to boot, and insofar as we normally dont do readahead, we only read the part we want.. > > >> The "algorithms" are in the 'ar' driver, which should really just be a > >> vinum shim. > > > > Well, the way vinum is implemented that wont work unfortunately. > > Details? Vinun monopolises the disk by putting varius data in areas of the disk, that wont play ball with native RAID's if the disks needs to be bootable and shareable with other OS's. -Søren To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message