When you need to add a hard disk or network interface cards on the new VMware virtual machine on the production server , but you are not allowed to shutdown the server, below is a solution.
1. Identify host bus number :
# ls /sys/class/scsi_host/ host0 host1 host2
2. Rescan the SCSI Bus to Add a SCSI Devices :
# echo "- - -" > /sys/class/scsi_host/host0/scan # echo "- - -" > /sys/class/scsi_host/host1/scan # echo "- - -" > /sys/class/scsi_host/host2/scan