I recently installed a UCS Mini with a direct-attached CS235 and configured the blades to boot from iSCSI. All was well with the initial ESXi installation until I received the attached error upon first boot to the LUN. Nimble Support was great and they only changed my iSCSI QoS settings from using Gold to Best Effort to get ESXi to see the Nimble volume as a proper boot LUN. Why is this the case regarding QoS? In addition, I am using jumbo frames and I was able to get everything to work with the Gold class when using standard 1500 byte frames.