Date: Mon, 10 Aug 1998 17:41:37 -0600 From: Brett Glass <brett@lariat.org> To: Doug White <dwhite@resnet.uoregon.edu> Cc: questions@FreeBSD.ORG Subject: Re: MSDOS extended partitions and "slices" Message-ID: <199808102342.RAA10483@lariat.lariat.org> In-Reply-To: <Pine.BSF.4.00.9808101631480.29015-100000@resnet.uoregon.ed u> References: <199808080608.AAA16222@lariat.lariat.org>
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At 04:35 PM 8/10/98 -0700, Doug White wrote: > >On Fri, 7 Aug 1998, Brett Glass wrote: > >> >This is fully normal. Extended partitions get mapped to extra slice >> >numbers since one extended partition can have multiple logical disks. >> >wd1s2 is the extended partition itself, which isn't that useful. >> >> But.... Waitaminnit. If you have an extended DOS partition with some >> number of logical DOS drives within it, you should REALLY see: >> >> C: wd1s1 >> Extended DOS partition: wd1s2 >> D: wd1s2a >> E: wd1s2b >> F: wd1s2c >> Third partition (FreeBSD, Linux, whatever): wd1s3 >> Fourth partition: wd1s4 >> >> This would be consistent with the actual structure. The logical DOS drives >> lie WITHIN the extended partition, which is one of the four possible >> partitions, or slices. > >It's a decent argument, but: > >1. There is a maximum of 8 partitions that can be defined this way (a-h). Why? Even if, for some reason, there's a limitation in the UNIX file system software that precludes more than 8, there should not be any problem doing this for MS-DOS "extended partitions" within MSDOSFS. >2. The B partition is only used for swap. >3. Letters C and D are reserved for the slice partition and the > whole-disk partition in BSD parlance, respectively. >4. I bet I'd get people trying to disklabel an extended MSDOS partition. Those are the conventions for a UNIX partition. But why apply them to other kinds? It's a good idea, methinks, to allow as much interoperability as possible, and to make sure that the device letters reflect the actual structure of whatever file system is being used. Otherwise, support for other systems, such as NTFS, etc., could be hampered. --Brett To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-questions" in the body of the message
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