SAN booting is the general term for booting a host from a storage system LUN instead of an internal hard disk.
Fibre Channel SAN booting does not require support for special SCSI operations; it is not different from any other SCSI disk operation. The HBA uses special code in the BIOS that enables the host to boot from a LUN on the storage system.
iSCSI SAN booting also uses special code in the BIOS that enables the host to boot from a LUN on the storage system. You need to set specific parameters in the BIOS to enable iSCSI SAN booting.
The general process is as follows.