Date: Wed, 4 Mar 1998 20:14:47 +0100 (MET) From: Wilko Bulte <wilko@yedi.iaf.nl> To: shimon@simon-shapiro.org Cc: grog@lemis.com, sbabkin@dcn.att.com, tlambert@primenet.com, jdn@acp.qiv.com, blkirk@float.eli.net, hackers@FreeBSD.ORG Subject: Re: SCSI Bus redundancy... Message-ID: <199803041914.UAA01584@yedi.iaf.nl> In-Reply-To: <XFMail.980303215215.shimon@simon-shapiro.org> from Simon Shapiro at "Mar 3, 98 09:52:15 pm"
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As Simon Shapiro wrote... > > On 04-Mar-98 Greg Lehey wrote: > ... > > >> The only problem I have here, is the assumption that the O/S will do all > >> that. Not only it consumes much CPU, I/O bus, memory bandwidth, etc., > >> but > >> O/S crashes are the number one cause of failure in any modern > >> computer. > > > > Sure. > > > >> Putting all this logic there is asking for it to crash frequently, > >> and run under load all the time. > > > > I don't think you can assume that. The load depends on the input. > > The reliability depends on the quality of the code. > > It does not matter at all how good your code is. It matterswhat the sound > driver decided to do, the PPP driver, the x25 driver, X11, serial console, > etc. There is no compartmentalizing in Unix. This means that any failure > in totally unrelated code WILL crash your code. In a RAID controller, as > long is power is applied, and the hardware did not fail, the firmware has > to worry about only one thing; the firmware. There are fewer interrupts, > fewer processes, simpler O/S, no filesystem topaic with freeing free inode. And best of all: no users.. We all know that systems tend to stay up much longer when left alone (read: dedicated to say WWW serving or something like that). > No, I use FreeBSD for the last 18 months. Seagate claims, in writing > 1,000,000 hours mean time between failures on their drives. Can FreeBSD Read the fine print on MTBF: it applies to large enough populations. You as Joe Average user will never have a statistically sound sample to claim anything. So they can essentially write down what they like. > make that claim? Can Tandem make this claim about their O/S? No operating > system written today (or EVER) can honestly make this claim. I think > Seagate is full of it with this million hours nonsense. But 5 years of > contineous operation is reasonable. I have Fujitsu drives and some > Micropolis drives with that much contineous operation on them. Zero > failures _ ______________________________________________________________________ | / o / / _ Bulte email: wilko @ yedi.iaf.nl http://www.tcja.nl/~wilko |/|/ / / /( (_) Arnhem, The Netherlands - Do, or do not. There is no 'try' --------------- Support your local daemons: run [Free,Net,Open]BSD Unix -- To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message
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