On Tue, 16 Nov 1999, Wenchi Liao wrote:

> How does netbsd deal with extended partitions? My recollection
> is fuzzy, but I though netbsd's fdisk doesn't even seen the
> extended partitions.

The first logical drive in the extended partition always starts one
track in (usually 63 sectors). Below, wd0f is the "D:" drive.

-> fdisk

NetBSD disklabel disk geometry:
cylinders: 7944 heads: 16 sectors/track: 63 (1008 sectors/cylinder)

BIOS disk geometry:
cylinders: 992 heads: 128 sectors/track: 63 (8064 sectors/cylinder)

Partition table:
0: sysid 6 (Primary 'big' DOS, 16-bit FAT (> 32MB))
    start 63, size 4185153 (2043 MB), flag 0x80
	beg: cylinder    0, head   1, sector  1
	end: cylinder  519, head   0, sector  1
1: sysid 5 (Extended partition)
    start 4185216, size 1911168 (933 MB), flag 0x0
	beg: cylinder  519, head   0, sector  1
	end: cylinder  756, head   0, sector  1
2: sysid 169 (NetBSD)
    start 6096384, size 1903104 (929 MB), flag 0x0
	beg: cylinder  756, head   0, sector  1
	end: cylinder  991, head 127, sector 63
3: <UNUSED>

-> disklabel wd0

# /dev/rwd0d:
type: unknown
disk: mydisk
label: 
flags:
bytes/sector: 512
sectors/track: 63
tracks/cylinder: 16
sectors/cylinder: 1008
cylinders: 7944
total sectors: 8007552
rpm: 3600
interleave: 1
trackskew: 0
cylinderskew: 0
headswitch: 0		# milliseconds
track-to-track seek: 0	# milliseconds
drivedata: 0 

8 partitions:
#        size   offset     fstype   [fsize bsize   cpg]
  a:   304416  6096384     4.2BSD     1024  8192    16   # (Cyl. 6048 - 6349)
  b:   264096  6400800       swap                        # (Cyl. 6350 - 6611)
  c:  1911168  6096384     unused        0     0         # (Cyl. 6048 - 7943)
  d:  8007552        0     unused        0     0         # (Cyl.    0 - 7943)
  f:  1911105  4185279      MSDOS                        # (Cyl. 4152*- 6047)
  g:  1342656  6664896     4.2BSD     1024  8192    16   # (Cyl. 6612 - 7943)
  h:  4185153       63      MSDOS                        # (Cyl.    0*- 4151)

-> cat /etc/fstab

/dev/wd0a /	ffs	rw 1 1
/dev/wd0b none	swap	sw 0 0
/dev/wd0b /tmp	mfs	rw 0 0
/dev/wd0g /usr	ffs	rw 1 1
/dev/wd0h /c	msdos	ro,noauto 1 1
/dev/wd0f /d	msdos	rw,noauto 1 1
...