CAUTION: NOT VERIFIED WITH YOUR HARDWARE SETUP!
You may either use some custom script that does the work for you (as the hp_rescan tool that is shipped with Qlogic HBAs) or you may manually reset the SCSI bus to trigger a rescan:
# echo " 1 " > /sys/class/fc_host/hostH/issue_lip
# echo “- - -” > /sys/class/scsi_host/hostH/scan
But this may vary with the hardware you use!!!