Subject: Re: A new partition handling scheme: wedges
To: Ignatios Souvatzis <email@example.com>
From: Manuel Bouyer <firstname.lastname@example.org>
Date: 01/26/1998 15:24:13
On Jan 26, Ignatios Souvatzis wrote
> Wolfgang writes:
> > Extended partitions are just like the complete disk, i.e. they have a MBR
> > of their own and thus can have again 4 partitions. And yes, AFAIK that's
> > the way Linux _does_ their partitioning...
> No, they're even sicker.
> they create a type linux-root partition for 'a', and an extended partition
> for the rest of the disk.
> They create, inside that, a type linux-swap partition for 'b', and an extended
> partition for the rest of the disk.
> They create, inside that, ...
Hum, They don't always do that:
NetBSD chauveau.ipv6.lip6.fr 1.3_BETA NetBSD 1.3_BETA (ANTIFER) #7: Tue Jan 13 14:12:47 MET 1998 email@example.com:/usr/src/NetBSD/src/sys/arch/i386/compile/ANTIFER i386
******* Working on device /dev/rsd0d *******
Warning: BIOS sector numbering starts with sector 1
parameters extracted from in-core disklabel are:
cylinders=3072 heads=33 sectors/track=63 (2079 sectors/cylinder)
Figures below won't work with BIOS for partitions not in cylinder 1
parameters to be used for BIOS calculations are:
cylinders=1024 heads=99 sectors/track=63 (6237 sectors/cylinder)
Information from DOS bootblock is:
0: sysid 131 (Linux native)
start 63, size 62307 (30 MB), flag 0x0
beg: cylinder 0, head 1, sector 1
end: cylinder 9, head 98, sector 63
1: sysid 131 (Linux native)
start 62370, size 617463 (301 MB), flag 0x0
beg: cylinder 10, head 0, sector 1
end: cylinder 108, head 98, sector 63
2: sysid 165 (NetBSD or FreeBSD or 386BSD)
start 679833, size 1234926 (602 MB), flag 0x80
beg: cylinder 109, head 0, sector 1
end: cylinder 306, head 98, sector 63
3: sysid 5 (Extended DOS)
start 1914759, size 4471929 (2183 MB), flag 0x0
beg: cylinder 307, head 0, sector 1
end: cylinder 1023, head 98, sector 63
So linux can also use 'flat' partitions. Maybe they improved fdisk :)
But what you've said means that linux can use extended partition inside
Manuel Bouyer, LIP6, Universite Paris VI.