With the new vSAN Express Storage Architecture (ESA), you may need to carefully plan your migration path from vSAN 7 to vSAN 8. At the moment, VMware only supports greenfield deployments of vSAN ESA. As a result, even if you have a vSAN cluster with NVMe storage, you will need to migrate your workloads to a new cluster to reach vSAN ESA. Furthermore, if you are moving from SSD to NVMe, you’ll need to ensure your order of operations is correct.

The following graph illustrates your possible migration and upgrade paths:

Your fastest path to ESA is to leave your existing cluster at the vSphere 7 level and create a vSphere 8 ESA cluster after upgrading to vCenter 8.

It’s important to consider both your vSphere and vSAN licensing during this process. For one, you will incur dual licensing for the duration of the migration. But you should also be aware that your vSAN license is tied to your vCenter version rather than your vSphere version. KB 80691 documents the fact that after upgrading to vCenter 8, your vSAN cluster will be operating under an evaluation license until you obtain vSAN 8 licenses. You should work with VMware to ensure both proper vSphere and vSAN licensing throughout this transition process.