From owner-freebsd-scsi Sat Sep 7 16:02:57 1996 Return-Path: owner-freebsd-scsi Received: (from root@localhost) by freefall.freebsd.org (8.7.5/8.7.3) id QAA20191 for freebsd-scsi-outgoing; Sat, 7 Sep 1996 16:02:57 -0700 (PDT) Received: from po1.glue.umd.edu (po1.glue.umd.edu [129.2.128.44]) by freefall.freebsd.org (8.7.5/8.7.3) with ESMTP id QAA20160; Sat, 7 Sep 1996 16:02:23 -0700 (PDT) Received: from fiber.eng.umd.edu (fiber.eng.umd.edu [129.2.98.185]) by po1.glue.umd.edu (8.8.Beta.0/8.7.3) with ESMTP id TAA01665; Sat, 7 Sep 1996 19:02:19 -0400 (EDT) Received: from localhost (chuckr@localhost) by fiber.eng.umd.edu (8.7.5/8.7.3) with SMTP id TAA29592; Sat, 7 Sep 1996 19:02:18 -0400 (EDT) X-Authentication-Warning: fiber.eng.umd.edu: chuckr owned process doing -bs Date: Sat, 7 Sep 1996 19:02:18 -0400 (EDT) From: Chuck Robey X-Sender: chuckr@fiber.eng.umd.edu To: Brian Tao cc: Ken Lam , FREEBSD-HACKERS-L , FREEBSD-SCSI-L Subject: Re: Streamlogic RAIDION drive arrays In-Reply-To: Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-freebsd-scsi@freebsd.org X-Loop: FreeBSD.org Precedence: bulk On Sat, 7 Sep 1996, Brian Tao wrote: > On Wed, 28 Aug 1996, Ken Lam wrote: > > > > I didn't get a chance to test it under FreeBSD. Fairly fast, but > > other than the RAID 5 aspect, why not use CCD? > > Well, ccd is a start, and I may consider it more seriously if the > costs of hardware RAID prove to be too high (we're looking at 5 or 6 > 6-drive units to start). ccd is free, but it doesn't give you > hot-swappable drives, automatic data rebuild on a spare drive > and a battery-powered write back cache. > > I'm going to stick with hardware RAID on the news servers, but ccd > should do just fine on our main mail server. Raw capacity is what I'm > aiming for there, not big TPS numbers or huge disk throughput. This seems somewhat odd to me. I thought you'd expend the additional cost of RAID where you really need reliability. If you lose news (assuming this doesn't happen very often) you just reload from another server, right? If you lose mail, it's gone, no backup at all. Raid (I understand) doesn't give you raw massive data, it gives you reliability at the cost of dollars and some lost capacity. CCD gives you the capacity completely, disk for disk, but doesn't allow the neat reliability features of a RAID box. If you're shooing for raw capacity, this doesn't seem to make sense. What am I missing? ----------------------------+----------------------------------------------- Chuck Robey | Interests include any kind of voice or data chuckr@eng.umd.edu | communications topic, C programming, and Unix. 9120 Edmonston Ct #302 | Greenbelt, MD 20770 | I run Journey2 and n3lxx, both FreeBSD (301) 220-2114 | version 2.2 current -- and great FUN! ----------------------------+-----------------------------------------------