Reporting from the Field Issue #6: Cisco UCS Pin Groups

A few weeks ago, I installed a UCS-B Smartplay bundle at a customer who is entrenched with HP Blades.  After the engagement, they were excited to migrate actual workloads to start seeing the benefits of UCS.  They had a dedicated Switching fabric for their vMotion traffic for their HP blades as to make sure that this traffic did not traverse their CORE network.

This caused some headache in how we were to migrate some of the workloads to UCS using VMware’s vMotion technology.  Unfortunately, the HP environment Blade Fabric only supported 1Gb, so the switches the customer purchased for vMotion were just that, 1Gb.

Since the storage was zoned for both blade systems, we had two options to get the workloads over to UCS:

1. We could shutdown the active VM’s during a maintenance window, remove the VM(s) form inventory and add them to the new Cisco UCS Cluster.  (Originally did this, customer did not want to deal with the overhead of this and making sure the APP was up etc)

2. We needed to bring the UCS Fabric into the customer’s current vMotion network and forcing vMotion out specific uplinks connected to that fabric.

In order to do this we ended up having to purchase a couple of GLC-T’s for dedicated Uplinks to the vMotion network.  We also had to “force” the vMotion traffic to use these Uplinks.  In order to do that we must create PIN groups and assign the vMotion vNIC’s to that Pin Group.

Let’s move on and show you the steps.  I am using the Cisco UCS Platform Emulator 2.2(1b) for this demonstration:

– Install the GLC-T Gbics and configure the Uplink Ports on Fabric A & B:


In our case we chose Port 10 on both FI’s:


Make sure that you are configuring the correct Speed setting for your Uplinks.  By default, it’s 10Gb, however in my customer’s case, their dedicated vMotion network only supported 1Gb so we have to change that to make sure that the links come up and are active:


After both Uplinks are configured it’s time to create our LAN Pin Group and assign to our Uplinks:


Once that is completed we can now change our vNIC’s for vMotion traffic to flow out those Uplinks and in our case back to the Customer’s vMotion Switching Fabric:


There ya have it.  Make sure that you are allowing the vMotion VLAN over the Trunks between the Fabric Interconnect and the vMotion Switch Fabric.  This requires configuration on both ends.

Also keep in mind that now that you’re pinning uplinks, other traffic will assume that it can go out those uplinks. Therefore I had to create another PIN group for MGMT and VM traffic as well.

This was a temporary solution for this customer until all workloads are migrated to UCS! Pinning should only be used for specific use cases and sparingly in my opinion.

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