Reading Time: 3 minutes After updating the vCenter Server part to version 5.5, you can focus on the host part. The update of the ESXi host can be completed, as usual, in several ways: Manual update with the installation CD of ESXi (by selecting upgrade and keep VMFS datastore) Manual update using the CLI Automatic updating via vSphere Update Manager (VUM) There are other ways, all discussed in the VMware KB 2058352 (Methods for upgrading to ESXi 5.5).