[CentOS] CentOS 5.5 does not recognise SAS drives with LSI 1068E Controller

Hmm, I am not sure if I understand you correctly: are you saying that
in the firmware configuration there might be an option that makes the
disks invisible for the OS?

Most controllers have a firmware you can enter at boot with a keystroke.
Once in, you create/prepare arrays or single drives, which the OS can then
see...