After you add a new disk on a Red Hat Linux server you can scan for the new disk without rebooting.
List the number of scsi host controllers
host0 host1 host2
Run this command to to scan each host0, host1 and host2
echo “- – -” /sysc/class/scsi_host/host0
Alternatively you can do all the above with this one line script
ls /sys/class/scsi_host/ | while read host; do echo “- – -“> /sys/class/scsi_host/$host/scan; done