first of all how can i detect what drives have not been installed. to note i cannot view the boot sequence since i am working on a remote machine. i think answering this question might be all i really need to know.
i have been attempting to use modprobe to load the modules for a scsi drive, however two things confuse me. one is that sda through sdh show up in devices. does that mean that they are already being loaded in the kernel. second where do i go to find modules?

The presence of files in /dev means absolutely nothing by itself. Nearly every entry in /dev is just a placeholder in case you happen to have that device.

You can view the boot messages using "dmesg"

# lsmod

Do you see a module loaded for your scsi card?

# dmesg | grep sd

How many sdX devices do you see that the kernel detected. sda will be the first and they'll go up alphabetically from there.

# modprobe SCSICARDMODULENAME

If the module for your SCSI card isn't loaded. Then check with "dmesg" to see what devices are available.

# dmesg | more

Look for the lines in the vicinity of the lines having to do with the detection of sda and other devices to see what they are, etc...

If it's a hard drive:

# fdisk /dev/sda

To view the partitions on the drive which are /dev/sda1 /dev/sda2 etc...

Good luck

none of that seemed to work. the kernel didn't detect any sda devices. do i need to reconfigure it so that it will? if so any good how-tos?

Can you be more clear on your setup? Is root on a scsi disk or ide? Do you have a PCI SCSI controller card, and if so, what make and model?

What is the current output of "cat /proc/scsi/scsi"?

lsmod; what are the output results as they relate to scsi?

Can you specify what type of scsi devices you have that aren't working right now?

well the thing is i havent the foggist clue what scsi devices i have. all i know is that there are some sort of scsi hard drives connected to this server that arent showing up. the root is ide, definitely. lsmod gives me nothing scsi related. i believe there is a pci scsi controller - Adaptec AIC-7896U2/7897U2. i really just need to know how to find out whats connected, without physically looking at the machine.

oh and proc/scsi/scsi doesn't exist

Post the output of lspci.

Look at the output of dmesg and see if you have any messages relating to SCSI or Adaptec.

If that is the Adaptec controller installed then try:
modprobe aic7xxx

If /proc/scsi/scsi doesn't exist, it's a good sign you have a kernel with no scsi support.

Get one, and make sure it has the driver michaelk says (aic7xxx). Like he says, it's the one you need.