Linux with docking station

Experts,

I have Precision M70 with dual-boot OS. Windows XP and RHEL WS3
For the hardware configuration, I have 60GB internal disk, 60GB external disk with Dell modular bay and DVDROM. I installed external disk in laptop modular bay and DVDROM in docking modular slot


so far, I have no problem with Windows XP

When I boot Linux OS, I could not recognize DVD ROM and external disk

Could anybody help to let me know how to configure these?

please advise,

regards,

Ario