Date: Fri, 23 Nov 2001 03:18:01 -0800 From: "Ted Mittelstaedt" <tedm@toybox.placo.com> To: "Robert Suetterlin" <robert@mpe.mpg.de> Cc: <freebsd-questions@FreeBSD.ORG> Subject: RE: why are You asking here Message-ID: <008401c17410$83770a40$1401a8c0@tedm.placo.com> In-Reply-To: <20011123112138.A6496@robert2.mpe-garching.mpg.de>
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>-----Original Message----- >From: Robert Suetterlin [mailto:robert@mpe.mpg.de] >Sent: Friday, November 23, 2001 2:22 AM >To: Ted Mittelstaedt >Subject: Re: why are You asking here > > >Hello Ted, > Hi Robert I hope you don't mind me cc'ing the list. >On Fri, Nov 23, 2001 at 02:08:35AM -0800, Ted Mittelstaedt wrote: >> Gee - why are you asking here? For the publicity value alone Sun should be >> willing to give you all hardware and a lot of software support for free. > >Sun already thinks about this problem. But this does not mean that >they will find >a solution. Well, asking FreeBSD to solve a problem that Sun can't solve is a bit surprising, you must have a lot of faith in us. >And any Solaris based solution will force a Sparc powered >hardware. This will use a large amount of our 200W hard limit on power >consumption. > Um - there ARE Sparc laptops so I think they have dealt with this already. But in any case, I'll make a few points here: 1) The power consumption and all that, while it's important, is not something that FreeBSD can solve for you. This is purely a hardware issue. Now, if you have some hardware already in mind that you think can do it and your just looking for an OS to run it - well that's something else, tell us what it is. If not - well I think your first stop is the hardware mailing lists. 2) While you outlined the problem your looking at: Our experiment needs to record a data stream (uncompressed images) at approx 260MByte per Second. In bursts of 45Minutes. Over 5-10 years, with periodic (i.e. Shuttle Mission Interval) replacement of permanent storage (best would be tape). what struck me is that your not saying anything about weight limits. Well I'm not an expert here but it seems to me that it must cost hundreds, perhaps thousands of dollars per pound to lift anything into orbit. That would seem to indicate that with the size of data storage your talking about, that your primary concern should be getting the densest storage medium possible, as even the most expensive and densest storage medium available today no matter how expensive it is, is going to pale in cost to the money needed to lift it up to the ISS. I am not at all convinced that tape storage is any kind of answer for you. Besides the fragility of the medium, there's the fragility of the recording mechanism itself. All tape drives, being mechanical things, will wear and drift out of alignment. I simply cannot imagine any kind of data tape drive manufactured today lasting for 5-10 years with any reasonable amount of use, and a considerable amount of weight and space will be consumed by the cartrige, mechanism, etc. Wouldn't you really be needing to look at something completely solid state here? I mean, there's flash cards that sell on the street that will hold a gigabyte, surely someone could custom-build something for you that would hold a lot more than this. 3) What exactly is a HSM going to do for you? HSM's are useful if you have a lot of data with perhaps 30% of it being regularly accessed, 30% of it being seldom accessed, and 30% being archived only. They do nothing for you if all your doing is archiving it once then never accessing it again until the tapes are flown back down. Ted Mittelstaedt tedm@toybox.placo.com Author of: The FreeBSD Corporate Networker's Guide Book website: http://www.freebsd-corp-net-guide.com To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-questions" in the body of the message
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