Noms des entrées de /dev correspondant à chaque partition ?

[Stephane Bortzmeyer <stephane%sources.org@localhost>]

J'ai sur un PC un disque ainsi partitionné, avec une partition étendue
pour y mettre des disques qui seront utilisés par Linux :

% sudo fdisk wd0
fdisk: Cannot determine the number of heads
Disk: /dev/rwd0d
NetBSD disklabel disk geometry:
cylinders: 39813, heads: 16, sectors/track: 63 (1008 sectors/cylinder)
total sectors: 40132503

BIOS disk geometry:
cylinders: 1023, heads: 255, sectors/track: 63 (16065 sectors/cylinder)
total sectors: 40132503

Partition table:
0: NetBSD (sysid 169)
    start 63, size 24386607 (11908 MB, Cyls 0-1517), Active
1: Ext. partition - LBA (sysid 15)
    start 24386670, size 15745833 (7688 MB, Cyls 1518-2498/33/54)
2: <UNUSED>
3: <UNUSED>
Extended partition table:
E0: Linux native (sysid 131)
    start 24386733, size 7164927 (3498 MB, Cyls 1518-1963)
        PBR is not bootable: All bytes are identical (0x00)
E1: Linux swap or Prime or Solaris (sysid 130)
    start 31551723, size 530082 (259 MB, Cyls 1964-1996)
        PBR is not bootable: Bad magic number (0x666f)
E2: Linux native (sysid 131)
    start 32081868, size 7164927 (3498 MB, Cyls 1997-2442)
        PBR is not bootable: Bad magic number (0x8fe6)
E3: Linux swap or Prime or Solaris (sysid 130)
    start 39246858, size 885645 (432 MB, Cyls 2443-2498/33/54)
        PBR is not bootable: All bytes are identical (0x00)
First active partition: 0
Drive serial number: 1054424792 (0x3ed93ed8)

La partition 0, NetBSD, marche bien (NetBSD 5.0) et est elle-même
découpée via disklabel.

% sudo disklabel wd0
# /dev/rwd0d:
type: unknown
disk: MAXTOR 6L020J1 
label: 
flags:
bytes/sector: 512
sectors/track: 63
tracks/cylinder: 16
sectors/cylinder: 1008
cylinders: 39813
total sectors: 40132503
rpm: 3600
interleave: 1
trackskew: 0
cylinderskew: 0
headswitch: 0           # microseconds
track-to-track seek: 0  # microseconds
drivedata: 0 

16 partitions:
#        size    offset     fstype [fsize bsize cpg/sgs]
 a:   1043280        63     4.2BSD   1024  8192     0  # (Cyl.      0*-   1035*)
 b:    639072   1043343       swap                     # (Cyl.   1035*-   1669*)
 c:  24386607        63     unused      0     0        # (Cyl.      0*-  24193*)
 d:  40132503         0     unused      0     0        # (Cyl.      0 -  39813*)
 e:   6144768   1682415     4.2BSD   2048 16384     0  # (Cyl.   1669*-   7765*)
 f:   2458512   7827183     4.2BSD   2048 16384     0  # (Cyl.   7765*-  10204*)
 g:  13893138  10285695     4.2BSD   2048 16384     0  # (Cyl.  10204*-  23986*)

Mais les partitions étendues (E0, E1, etc) me posent problème? Quel
est leur nom dans /dev, que je puisse les attaquer avec newfs ou
mke2fs ? Où trouver cette information ? Un peu au hasard, j'ai
essayé :

% sudo mke2fs /dev/wd0h
mke2fs 1.40.7 (28-Feb-2008)
mke2fs: Device not configured while trying to determine filesystem size

% sudo mke2fs /dev/wd1a
mke2fs 1.40.7 (28-Feb-2008)
mke2fs: Device not configured while trying to determine filesystem size

% sudo mke2fs /dev/wd1b
mke2fs 1.40.7 (28-Feb-2008)
mke2fs: Device not configured while trying to determine filesystem size

mais sans résultat.