Messages in this thread | | | Subject | Re: when is label info commited to disk? | Date | Sun, 13 Jul 1997 11:08:50 PDT | From | "Marty Leisner" <> |
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In message <9707121914.AA16161=aeb@texel.cwi.nl>, you write: >Marty Leisner: > >: Are there instructions on how to create an extended linux partition? > >An extended Linux partition differs in no way from an extended DOS >partition, except that the IDs are 85 and 05 (hex), respectively. > >What is the use? >DOS FDISK will crash or worse when it reads a chain of extended >partitions passing the 1024 cylinder boundary. Since DOS does not >recognize 85, this enables you to make DOS happy and still have a >series of extended partitions past the 1024 cylinder mark. > >How to create? >Any sufficiently recent *fdisk will do, I think. >Try cfdisk, sfdisk and fdisk. > cfdisk painlessly lets you create a primary or extended partitions in one partition.
But I think all the fdisk programs will fail when we start creating multiple extended partitions on one disk (is there a limit?)
If we have an extended dos and extended linux partition (assuming we already created it), how do we tell our *fdisk program which slice to add the parititon to?
>: If I make hda2/hda3 extended linux partitions, the kernel counting >: mechanism will screw up /dev/hda4 > >Screw up in what way? What is your complaint?
If /dev/hda5 sits in /dev/hda4 now, and then I add extended partitions to /dev/hda3, what used to be /dev/hda5 may be /dev/hda7.
I think the labeling needs to be rethought, since its too easy to wreak havoc on a working system. The BSD file system also has the same problem (does the newest 2.1. incarnations work with freebsd?) I think the following would work much better: /dev/hd*1 extended partitions would be in /dev/hd*10-19 /dev/hd*2 extended partitions would be in /dev/hd*20-29 /dev/hd*3 extended partitions would be in /dev/hd*30-39 /dev/hd*4 extended partitions would be in /dev/hd*40-49
What I'm proposing is a strategy to make disk slices independent of other slices on the same disk...
>Do you know what you are doing when you create two chains of >extended partitions? Sometimes that is the only solution, >but usually it is just a very bad idea. > Actually, if you have a large disk, and create 2 extended partitions chains (lets say, each holding several gig) I don't see it as a bad idea.
marty
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