You may find the scsi_id command returns a null result in CentOS 6 or RHEL 6 on VMware.

[root@localhost ~]# scsi_id -g -u -d /dev/sdb
[root@localhost ~]#

 
The problem here is that VMware Workstation does not provide unique SCSI identifiers to the virtual SCSI devices. We need to modify the VMX file to make this happen by adding the following directive:

disk.EnableUUID = "TRUE"

 
Restart the VM and now the scsi_id command should work:

[root@localhost ~]# scsi_id -g -u -d /dev/sdb
36000c2980c56d98cc5150a0ac103058d