Messages in this thread | | | Date | Fri, 15 Jan 1999 20:20:16 -0500 (EST) | From | "Theodore Y. Ts'o" <> | Subject | Re: (un)corrupted ext2 partitions |
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Date: Fri, 15 Jan 1999 22:57:44 +0000 (GMT) From: Riley Williams <rhw@BigFoot.Com>
From what I've read, I gained the impression that there are in fact TWO ways that the partition tables in an extended partition can be used, but from Ted's comments above, that appears not to be the case. Could I ask somebody to straighten me out on this please, and tell me what I've got wrong...
1. An extended partition starts with its own partition table, which, like tha master partition table, has four entries.
2. The way MSDOS uses this partition table is to put the limits for a partition in the first entry, and then specify the rest of that extended partition as being ANOTHER extended partition in the fourth entry, with its own partition table at the beginning, and to repeat the process until all space is allocated.
This is what I was referring to; note that if you lose one of the extended partitions, being able to find the rest of extended partitions after that one becomes.... interesting.
3. An alternative way to handle extended partitions, which both MSDOS and Win9x recognise, although neither creates, is to use multiple entries in the base partition table for up to three valid partitions (four if they fill the entire extended partition) before allocating another extended partition to deal with the rest of them.
I'm not aware of any fdisk which creates extended partitions in this way; I didn't even realize that MSDOS and Win9x would recognize it. The thing which would make me nervous is what would happen if some fdisk program which was expecting the standard way of handling extended partitions tried to modify an extended partition table that was set up in this way.
- Ted
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