The importance of using templates with Cisco UCS cannot be emphasized enough. Creating something that you can reuse over and over again, as well as update and push out to pre-created objects, can save you a ton of time from an administrative perspective. vNIC and vHBA templates are a great example of this within Cisco UCSM. These templates allow you to create reusable vNIC and vHBA objects that you can reference within the creation of a service-profile template or even a LAN/SAN connectivity policy.
You can reach even further with policies and template on UCS, and create what are known as LAN and SAN connectivity policies. These will allow us to pre-create the LAN and SAN connections for service profiles and service profile templates. Take this for example. Say we knew that we were going to deploy a lot of ESXi servers in our environment, and that they would all essentially have the same exact LAN requirements in terms of the number of NICs that they needed, and the VLANs that they would need for the hosts themselves, as well as the guest machines. We could create a connectivity policy for these servers, and reuse that policy in all of our service profiles, and/or templates! To begin the process we will want to navigate to our LAN tab, and filter to policies. If you right-click on ‘LAN Connectivity Policies,’ UCS will allow you to create a new one. Here I create one called ESXi-LCP:
It now asks us to create our “network.” We will want to click ‘add’ to create the vNICs that we will be using. Notice that once you get in here, that we can even reference our existing vNIC templates to save ourselves even more time! Here is a screenshot of the first vNIC that I created within my policy:
I wont show you both of them, but we will just create our 2 vNICs here, referencing our existing vNIC templates.
Once complete, we have a policy that we can use within our SP or SP-templates to save us a ton of time on something that we normally would have to do over and over. Below is an example of me applying the LAN connectivity policy inside of a service profile:
Now what we have ultimately done here is used vNIC templates inside of our LAN connectivity policy. This means that later if we say, had to add a VLAN to those vNICs, that we could just change it on the vNIC template and those changes would be pushed to all of the vNICs that had been derived from those templates (as long as we used an updating vNIC template)! We can do the same exact process from the storage side as well. We can create vHBA templates and SAN connectivity policies to pre-provision all of our existing or future connectivity down to our stateless computing environment.
Now, this might be a process that I leverage in the CCIE lab depending on a few things. Verbiage of course is going to lead you down one path or another during your exam. However, if not told to do otherwise, and if I had multiple service profiles, or SP-templates to create that all used the same pools, and vNIC/vHBA structure, I might be tempted to leverage these in order to save a bit of time. Odds are though, that these will be much more useful in normal day-to-day administration of UCS systems within your existing environments.