私のところのdmesgの出力の抜粋は以下の通り。

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ide: i82371 PIIX (Triton) on PCI bus 0 function 57
    ide0: BM-DMA at 0x7030-0x7037
    ide1: BM-DMA at 0x7038-0x703f
hda: QUANTUM FIREBALL ST4.3A, 4110MB w/81kB Cache, CHS=524/255/63, DMA
hdc: MATSHITAPD-1 LF-1196, ATAPI CDROM drive - enabling SCSI emulation
ATAPI overlap supported: No
hdd: FUJITSU MPA3026ATU, 2503MB w/0kB Cache, CHS=5086/16/63, DMA
ide0 at 0x1f0-0x1f7,0x3f6 on irq 14
ide1 at 0x170-0x177,0x376 on irq 15
scsi0 : SCSI host adapter emulation for IDE ATAPI devices
scsi : 1 host.
  Vendor: MATSHITA  Model: PD-1 LF-1196      Rev: A103
  Type:   CD-ROM                             ANSI SCSI revision: 02
Detected scsi CD-ROM sr0 at scsi0, channel 0, id 0, lun 0
  Vendor: MATSHITA  Model: PD-1 LF-1196      Rev: A103
  Type:   Optical Device                     ANSI SCSI revision: 02
Detected scsi removable disk sda at scsi0, channel 0, id 0, lun 1
scsi : detected 1 SCSI cdrom 1 SCSI disk total.
sda : READ CAPACITY failed.
sda : status = 0, message = 00, host = 0, driver = 28
sda : extended sense code = 2
sda : block size assumed to be 512 bytes, disk size 1GB.
ne2k-pci.c:v0.99L 2/7/98 D. Becker/P. Gortmaker http://cesdis.gsfc.nasa.gov/linux/drivers/ne2k-pci.html
ne2k-pci.c: PCI NE2000 clone 'RealTek RTL-8029' at I/O 0x7000, IRQ 11.
eth0: PCI NE2000 found at 0x7000, IRQ 11, 52:54:00:DB:1F:C7.
Partition check:
 sda:scsidisk I/O error: dev 08:00, sector 0, absolute sector 0
 unable to read partition table
 hda: hda1 hda2 < hda5 hda6 > hda3 hda4
 hdd: [PTBL] [635/128/63] hdd1 hdd2 hdd3
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この場合、/dev/scd0 でCD-ROMに、/dev/sda? でPDに、それぞれアクセスできる。