This one liner shows how to get Linux (CentOS in this case) to detect a newly added disk on a VMWare host. This was found on “http://wingloon.com/2013/05/07/how-to-detect-a-new-hard-disk-without-rebooting-vmware-linux-guest/”.
ls /sys/class/scsi_host/ | while read host ; do echo "- - -" > /sys/class/scsi_host/$host/scan ; done
There you have it.