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Path: euryale.cc.adfa.oz.au!newshost.carno.net.au!harbinger.cc.monash.edu.au!news.cs.su.oz.au!metro!metro!munnari.OZ.AU!news.ecn.uoknor.edu!news.wildstar.net!news.ececs.uc.edu!newsfeeds.sol.net!newspump.sol.net!howland.erols.net!news.sprintlink.net!news-peer.sprintlink.net!news.bbnplanet.com!cpk-news-hub1.bbnplanet.com!newsfeed.internetmci.com!news.corpcomm.net!news From: Zach Heilig <zach@blizzard.gaffaneys.com> Newsgroups: comp.os.linux.misc,comp.os.linux.setup,comp.unix.bsd.bsdi.misc,comp.unix.bsd.misc Subject: Re: IDE vs SCSI (was Re: Linux vs BSD) Date: 24 Jan 1997 06:29:09 -0600 Organization: Corporate Communications Lines: 29 Sender: zach@murkwood.gaffaneys.com Message-ID: <87enfbb6ju.fsf@murkwood.gaffaneys.com> References: <32DFFEAB.7704@usa.net> <5c155c$p6u@raven.eva.net> <87k9p4rckd.fsf_-_@murkwood.gaffaneys.com> <5c8a39$7tn@usenet.srv.cis.pitt.edu> NNTP-Posting-Host: dialup9.gaffaneys.com Mime-Version: 1.0 (generated by tm-edit 7.89) Content-Type: text/plain; charset=US-ASCII X-Newsreader: Gnus v5.3/Emacs 19.34 Xref: euryale.cc.adfa.oz.au comp.os.linux.misc:154048 comp.os.linux.setup:93754 comp.unix.bsd.bsdi.misc:5723 comp.unix.bsd.misc:2015 hahn@neurocog.lrdc.pitt.edu (Mark Hahn) writes: > : It is possible with some high-end SCSI controllers to offload the > : entire file-system code from the operating system into the controller, > I've never heard of this. in fact, the SCSI protocol doesn't > really encompass a concept of files... I admit I haven't actually seen any real products based on this either. I really should have said 'It should be possible...'. On second thought, I probably should have written it like this: Some SCSI controllers have an actual processor on board, with host accessable memory. The way these controllers are normally used is for the host to place a sequence of instructions in the memory, with an interrupt as the last instruction. FreeBSD uses these controllers as a separate CPU, and just sends it requests for selected sectors. This really doesn't have much to do with the SCSI spec, as far as I can tell. I don't think it is too much of a stretch to suggest that somebody add enough memory to support filesystem code, and have the controller card handle all the filesystem support. This would be just non-symetric multi-processing. -- Zach Heilig (zach@blizzard.gaffaneys.com) | ALL unsolicited commercial email Support bacteria -- it's the only | is unwelcome. I avoid dealing form of culture some people have! | with companies that email ads.