The problem with OpenFiler is: it assigns LUN 0 to each volume.
If you want to use more than one LUN within ESX, it results in double LUN ID’s. ESX wants unique LUNs so you have to change the configuration of openfiler.
On your openfiler box open the file /etc/ietd.conf.
You see a 2-line record for each volume, and each one has Lun id 0.
Change the Lun id’s to unique ascending numbers and save/close the file.
Restart the iSCSI services with the following command: service iscsi-target restart
The final step, start a “Rescan” with the option “Scan for New Storage Devices”