iSCSI Boot from SAN on Cisco UCS

Last week Cisco released the new 2.0 code for Cisco UCS.  I had some time to play with the update and tried out the new iSCSI Boot from SAN support feature to see how it works.  Here are some of the steps I used to get a VMware ESXi 5.0 host up and running via iSCSI storage on UCS.

Service Profile and vNIC Configuration

1)      In the UCSM, create a Service Profile.  This profile will be created as usual(except for vHBAs) but make sure that you create 2 vNICs that will be reserved for iSCSI traffic.  UCS will use these vNICs as “Overlay NICs” that will provide the VLAN connectivity details for the iSCSI vNICs in the Service Profile.

2)      Configure the VLANs on the Overlay vNICs by selecting the vNIC and clicking the Modify VLANs link in the working pane. 

3)      In the Modify VLANs window, Select your VLAN for iSCSI and select the “Native VLAN” radial button for the VLAN.  Making this the native VLAN for the Overlay vNICs will pass the frames for the iSCSI VLAN untagged and ease the configuration and installation of the OS.  Click OK, and then click the Save Changes button in the working pane for the vNIC.  Repeat these steps for the 2^nd vNIC that will be used as an Overlay vNIC for iSCSI.