The new PERC 5 and PERC 6 RAID controllers use SAS (Serial Attached SCSI), and a new driver, megaraid_sas. The new SAS 5 and SAS 6 non-RAID controllers use a new driver, mptsas, part of the mptfusion driver family. Both drivers are included in kernel.org 2.6.x kernels, and have been backported to the RHEL3 2.4.21-x kernels.