How do I change the order of storage devices during boot in RHEL 5 and 6?

Issue

• Originally the system has one local disk /dev/sda, then connected with a new external storage (a storage array or a fiber-channel or a SAS disk). After the system was booted up, the  internal disk on the server were changed to /dev/sdb while the external disks on the fiber storage were now /dev/sda.
• How to control storage device ordering during boot. For instance, having the local storage be mapped to sd names before the SAN storage. An example of this would /dev/sda being local and /dev/sdb being external.
• control storage order discovery between local RAID and HBA Qlogic
• control scsi device ordering during boot
• Sometimes when we reboot a server which take part in cluster (and only this server currently), the boot hang because HBA Qlogic card is seen as scsi0 instead of local RAID and so no boot partition is available.
• I have a problem with the server booting from SAN instead of local storage. How can I delay activiation of SAN storage until after the server has booted up properly?
• How to add persistent device names for local scsi device in Red Hat Enterprise Linux 5 / 6? We are seeing an issue on one of our RHEL6 server where we have device mapper multipath configured for SAN storage. SAN device names change on every reboot, causing local devices to acquire different names too? How can we prevent this?
• Root disk appears to be /dev/sde rather than expected /dev/sda
• Why does SAN device take /dev/sda device name?