RHEL 4.x or earlier, to find the WWPN run the cat /proc/scsi/adapter_type/n command, where adapter_type is the host adapter type, and n is the host adapter number for your card. In most cases, the adapter type is qla2xxx.

cat /proc/scsi/adapter_type/n

RHEL 5.x or later, the adapter WWPN information might not be available in the/proc/scsi/adapter_type/n directory because of the migration to sysfs, If so, run the following command:

cat /sys/class/scsi_host/hostn/device/fchost\:hostn/port_name