Why I Choose NIM to Install VIOS

Edit: This is still good stuff.

Originally posted January 13, 2015 on AIXchange

In May 2013 I wrote about installing the VIO server using the HMC GUI. This more recent article covers the same topic. At the end of Bart’s post he mentions using the virtual media repository, something I covered here.

While I have used the HMC GUI, I prefer to set up the NIM server and use it to load the VIO server. Bottom line, using NIM is faster than using the HMC GUI.

Of course, there are instances when NIM isn’t an option, such as IBM i environments that run VIO servers. Another example is a new or still under construction data center. Some of my customers fall into this category, and as a result I frequently do system builds in data centers that don’t yet have a NIM server. Often in these situations I don’t even have a network available, because the network guys are simultaneously installing and configuring their gear. Until the network is up and running, the physical machine is all I have.

So what are the options at this point? I could run crossover cables and get the HMC to talk to a network adapter on the system, and then use the HMC to install the VIO server. If there’s physical media, installing from a DVD is an option, although with smaller systems that have split back planes it can be tricky to use the DVD to install to a second VIO server.

In the past I’ve loaded the VIO server to internal disk, created a virtual media repository and copied VIO and AIX DVDs over to that repository. Then I use those .iso images to build a NIM server that’s booting from a free local drive. Once the NIM server is built, I can use it to create my second VIO server via the internal network. At least this allows me to load LPARs across the internal virtual network while I wait for my physical network to be built out. If you’re on a strict timeline (and really, when are we not?), this method can help you be productive as you wait for the network to become available.

 I’ve also been in situations where the network was running, but VLAN tagging was in place. In such a scenario, I would go into SMS and set up VLAN tagging for my remote IPL to use for booting. However, there’s no option that I know of to define a VLAN within the HMC GUI (if that’s what you’re using to install VIO server). Sure, this can typically be handled by asking a network admin to temporarily change the VLAN configuration, but of course, some network guys are more amenable to such a request than others. It’s something to be aware of.

Here’s another advantage to using NIM rather than install from the HMC: I had a customer that wanted to set up a third test VIO server using the HMC GUI. They had a spare fibre card, but no spare network card. This wasn’t an issue since they could put the VIO server onto an existing internal VLAN and communicate externally via the existing shared Ethernet adapters on their other two VIO servers. The problem was the GUI only recognizes physical adapters, not virtual ones. Using NIM, we were able to get it to work.

What’s your preferred way to install new systems?