VMC on AWS i4i Upgrade Process

The i4i is a new host type offering from VMC on AWS. Here are some tips on the how and why of upgrading.

First, let's tackle the 'Why'. The simple answer is that it is a newer and more powerful rig. Below are the current node types in VMC on AWS.

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The key to workload placement on VMC on AWS is achieving the most efficient utilization of CPU, Memory and Storage when placing VM workloads. As my colleagues can attest, I tend to preach that appropriate cloud operating models are all about intelligent workload placement. This is oversimplified, but with a few exceptions, the i3 was can be used for standard application workloads with careful examination of CPU intensive workloads as hyperthreading is disabled. The new i4i host type is appropriate for high performing application workloads and the i3en is generally utilized for high storage workloads and database workloads.

As for the 'How', there are a couple of choices here. VMware can handle the i3 to i4i host conversion for you in which case i3s would be decommissioned and replaced with i4i hosts. Or as an alternative, the customer can add new i4i clusters and migrate workloads themselves. As someone who has recently gone through this process, I highly recommend leveraging VMware to convert your hosts it if it fits the your use case as it relates to timing and subscription utilization. The process is seamless to the customer, and is by far the easiest path to conversion.

If you choose to perform the migration on your own, be sure to work with your account team to plan this out. Careful attention needs to be paid to subscriptions as well as migrating your management cluster.

What about sizing? I sometimes feel like half my time is spent sizing for on various migrations. This case is a bit unique as it is going from VMC to VMC, but changing host types. In general, we are seeing about a 2 to 1 ration going from i3 to i4i. It is however important to understand how the conversion process happens vs. the normal build out of a VMC on AWS environment. In most cases our customers will determine a cluster strategy, then simply begin migrating workloads and let eDRS dynamically add hosts as needed. Depending on your settings this will happen when thresholds around 80% are consistently met. This may end up with a cluster running at let's say 70% plus storage. That said, when our engineers are converting from i3 to i4i they will generally be more conservative and aim for 40% - 50% utilization across the main 3 metrics. At this point it is up to the customer (or eDRS in some cases) to remove hosts based on your comfort level and workload profile.

This is a new process, so it is important to work with your VMware account team when planning your conversion. They can advise you, and bring in resources as necessary. Hopefully, this provides at least a starting point for your consideration moving forward.