New EMC lun not being detected, even with echo scan command

Issue

• EMC LUN not detecting with echo scan command
• LUN being added to existing storage port
• Have tried rescan-scsi-bus.sh
• Have read and followed instructions in How do I rescan the SCSI bus to add or remove an SCSI device without rebooting the computer?, but the problem still exists
• Online scanning, including issue_lip, is not detecting the new LUNs but after a server reboot, it is showing the new LUNs. Why is that?
• The /proc/scsi/scsi list is LUNs 0-8 LUNs -- 9 LUNs -- but we have only 8 LUNs allocated to the system. Is the host not creating the device files? Where is the 9th LUN coming from?
• This has happened before and a reboot was necessary to see the new LUN, how do we avoid having to reboot?
• EMC LUNZ is present within LUN list and in /proc/scsi/scsi