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Newsgroups: comp.os.386bsd.misc Path: sserve!newshost.anu.edu.au!harbinger.cc.monash.edu.au!newshost.marcam.com!news.mathworks.com!noc.near.net!monk.proteon.com!jfw From: jfw@proteon.com (John Woods) Subject: Re: Bootable tapes: Message-ID: <D4Cz3z.49@proteon.com> Sender: news@proteon.com Nntp-Posting-Host: kerplop.proteon.com Organization: Proteon, Inc., Westborough, Ma. References: <Pine.BSI.3.91.950217120424.24130E-100000@mramirez.sy.yale.edu> <3i5qv7$drn@park.uvsc.edu> <3i70n7$t2t@deep.rsoft.bc.ca> <3i8hhl$pba@park.uvsc.edu> Date: Tue, 21 Feb 1995 16:28:47 GMT Lines: 27 Terry Lambert <terry@cs.weber.edu> writes: >The interesting case I was referring to is where you do that >rewrite and put it as the first extent on the tape, causing a kernel >to be loaded and a ramdisk created from the second extent, and then >installing from the third and subsequent extents. With the RAMdisk approach, you have to worry about minimum system sizes. If you're not in much of a hurry, you could, in principle, just use a filesystem image on tape (hmm, perhaps the UFS would have difficulty with that). A system I worked on a few years ago did exactly that; initializing the backup root partition with the contents of the tape's boot partition (and then fiddling the configuration file so it would boot the disk rather than the tape after reboot ;-) took over an hour, and would have been faster with a RAMdisk, but we had older, memory-starved installations to worry about. So you went to lunch while a new system installed itself, no big deal. At least the UNOS filesystem lent itself very well to being hand-tuned for tape use. >you would still need to convince the DOS boot vector (which was >hooked by your SCSI controller) to consider the tape as bootable >media. That's the real kicker. If one were desparate to do this, one could have a floppy that contained only tape-cognizant boot code (sort of a jump-start floppy), but that reduces the motivation somewhat (I suppose it cuts down on the number of media changes and reboots necessary for installing a new system).