From owner-freebsd-current Wed Oct 7 08:29:41 1998 Return-Path: Received: (from majordom@localhost) by hub.freebsd.org (8.8.8/8.8.8) id IAA11258 for freebsd-current-outgoing; Wed, 7 Oct 1998 08:29:41 -0700 (PDT) (envelope-from owner-freebsd-current@FreeBSD.ORG) Received: from home.dragondata.com (home.dragondata.com [204.137.237.2]) by hub.freebsd.org (8.8.8/8.8.8) with ESMTP id IAA11242 for ; Wed, 7 Oct 1998 08:29:37 -0700 (PDT) (envelope-from toasty@home.dragondata.com) Received: (from toasty@localhost) by home.dragondata.com (8.8.8/8.8.5) id KAA02281; Wed, 7 Oct 1998 10:29:20 -0500 (CDT) From: Kevin Day Message-Id: <199810071529.KAA02281@home.dragondata.com> Subject: Re: CDROM as system disk In-Reply-To: <199810071347.GAA03046@dingo.cdrom.com> from Mike Smith at "Oct 7, 98 06:47:11 am" To: mike@smith.net.au (Mike Smith) Date: Wed, 7 Oct 1998 10:29:20 -0500 (CDT) Cc: asami@cs.berkeley.edu, current@FreeBSD.ORG X-Mailer: ELM [version 2.4ME+ PL31 (25)] MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-freebsd-current@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG > > What do you guys think? Am I totally off the mark? > > Definitely. > > You have a reliability problem that you need to address. To start > with, you need to work out whether the problem is actually inherent in > the disks you're using, or whether it's environmental. > > Then you need to follow through; if its environmental (eg. heat, > humidity, etc.), fix it. If it really is the disks, consider using > better disks. Plenty of systems up 24/7 have disks 5 years old or more. > Consider using removable disk sleds and keeping some spares around. > > Dumping disks and going with CDROMs isn't going to help you > reliability-wise at all, and it'll hurt you in lots of other ways. > I agree here. I'm working on an embedded product, and one of the *big* reasons for using a hard drive, instead of CD-ROM is reliability. What's worse: newer CD-ROMS die faster than old ones. The faster the drive is trying to read data, the quicker it'll blow itself up. From what I can tell, a seek/read operation every 20-30 seconds will give you a 6X cdrom that'll last 3-9 months. Faster drives won't make it as long. I killed a 32X cdrom in 2 days of accesses every 40 seconds, which was just enough time for the read to complete, the drive to spin down, then when it had just spun down, time to spin up again, and read. Depending on if your delays between seeks are enough time for the drive to spin down or not are a big factor. (spin down/spin up/seek/read is nasty) Kevin To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-current" in the body of the message