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Path: sserve!newshost.anu.edu.au!munnari.oz.au!metro!sequoia!ultima!kralizec.zeta.org.au!kralizec.zeta.org.au!not-for-mail From: bde@kralizec.zeta.org.au (Bruce Evans) Newsgroups: comp.os.386bsd.questions Subject: Re: FreeBSD - sio (com) and DOS HD problems Date: 22 Sep 1993 09:33:18 +1000 Organization: Kralizec Dialup Unix Sydney: +61-2-837-1183 V.32bis Lines: 29 Message-ID: <27o2vuINNt51@kralizec.zeta.org.au> References: <1993Sep16.201358.26183@doug.cae.wisc.edu> <NEWSSERV!STARK!GENE.93Sep17075803@stark.uucp> NNTP-Posting-Host: kralizec.zeta.org.au In <NEWSSERV!STARK!GENE.93Sep17075803@stark.uucp> newsserv!stark!gene@cs.sunysb.edu (Gene Stark) writes: >So, I believe that if you expand the range of cylinders declared for the >BSD c partition, so that they cover the DOS area, you will then be able >also to define a new partition in the BSD disklabel that will allow you >access to the DOS area. This is backwards. You need to _reduce_ the range of the BSD C partition if it covers the DOS area (or any other foreign area). >The disklabel program has the hard-coded default idea that the disklabel >should be written at the beginning of the "a" (root) partition of the BSD area. >If the beginning of your "a" partition does not coincide with the beginning >of your "c" area, then the disklabel will be written in the wrong spot >and you will not be able to boot your system. This problem is easy to avoid once you know about it. You must have a nonempty A partition starting at the same place as the C partition. It's most important to have a nonempty A partition. Empty partitions usually have start 0, and disklabel takes an A partition starting at 0 as a license to overwrite the DOS partition table. There is a worse problem if you use bad144 sector forwarding. If there is a DOS partition table, then bad144 puts its tables at the end of the C partition. But everything else expects them to be at the end of the disk. This problem can be avoided by putting the 386BSD partition last and making the end of the C partition coincide with the end of the disk. -- Bruce Evans bde@kralizec.zeta.org.au