Date: Thu, 5 Mar 1998 08:20:33 +0100 (MET) From: Wilko Bulte <wilko@yedi.iaf.nl> To: shimon@simon-shapiro.org Cc: julian@whistle.com, hackers@FreeBSD.ORG Subject: Re: SCSI Bus redundancy... Message-ID: <199803050720.IAA08143@yedi.iaf.nl> In-Reply-To: <XFMail.980304152804.shimon@simon-shapiro.org> from Simon Shapiro at "Mar 4, 98 03:28:04 pm"
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As Simon Shapiro wrote... > > On 04-Mar-98 Wilko Bulte wrote: > > ... > > > free, like a $10-15 pricepoint. No real use for it here, but maybe fun > > to play with. Like the FDDI network here ;-) > > I am using FDDI (CDDI) here on my development setup. The DEC cards > supported by FreeBSD. Very boring setup; You plug them in and it works. Same experience here. 'Just works'. Picked mine up for $ 5 a piece. Should've bought more :< > Nice thing is it provides redundancy and does not need an expensive switch. I'm trying to get a FDDI hub, don't want to power up all boxes to use FDDI. > > An extra power supply is money well spent. We ship all our standalone > > arrays at least with N+1, optional 2N power. 2N gives you 2 seperate > > power entry points to the power grid. Now we only need to educate people > > to use two different power branches (phases? what's the right English > > term?) > > The old DPT 9W tower (made by DEC) had an interesting feature, where the > power INPUT was switchable too. If the AC to one supply went dowm it will > draw AC from the other. > > Yes, 2N P/S is trivial to do (2 diods/circuit if I remember right) and > cheap. Technically, you want each supply fed from a different phase. In > the US they are referredto as ``independant circuits''. I have seen people > paying lots of money to get that, where they have 220V right in the same > room (220BAC in the US is 2-phases, 180 degrees apart, unlike the European > 3 phasees 120 degrees apart. Yest, you can get 3phase circuits in the US > too). The hot wire in a 220VAC, in the us is 117VAC to ground, 220VAC > hot-hot. I don't think you can get 2phase power here. We're slowly moving from 220 -> 230. And ultimatly to 240. And 50Hz iso 60Hz op course. > >> To have the kernel actually checkpoint itself, with any better > >> resolution, > >> or intelligence will have to change too many things. I am trying to > >> make > > > > OK, that was my original question. Had a bad feeling about exactly what > > you mention here. > > What's bad? I would like to know if you think there is a mistake here. Well, bad in the sense of very complicated. Not in the sense of mistake. _ ______________________________________________________________________ | / 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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