In linux, the device paths for hard disks are as follows (assuming that you don't have devfs):
IDE Disks
/dev/hda = Primary Master
/dev/hdb = Primary Slave
/dev/hdc = Secondary Master
/dev/hdd = Secondary Slave
Each disk can have up to 63 partitions and the first partition on the PM is /dev/hda1, the second partition is /dev/hda2 etc.
CDROMs don't have partitions on them so if your CDROM is the SM then you access it via /dev/hdc
e.g. mount -t iso9660 /dev/hdc /cdrom
SCSI disks are different. linux assigns the paths /dev/sda, /dev/sdb etc. in the order in which it finds the disks.
/dev/sda will be the lowest LUN on the first controller found, /dev/sdb will be the next lowest LUN on the first controller OR the lowest LUN on the second controller found etc.
SCSI disks can have up to 15 partitions so the first partition on the first disk is /dev/sda1 etc.
If you don't change the SCSI configuration then the order will be the same everytime linux boots. However if you add/remove a disk then the mapping will be different.
AS with IDE disks you refer to a SCSI CDROM via the whole disk path e.g. /dev/sdb
hth.
The nice thing about computers is that they do exactly what you tell them. The problem with computers is that they do EXACTLY what you tell them.
