If something went wrong, thanks to the two independent boot banks, you have the option to roll back to the previous version.
To perform the rollback, follow these steps:
- Reboot your ESXi server.
- When the hypervisor progress bar starts loading, press Shift + R. You will see the following warning:
- Press Y to roll back the build.
- Press Enter to boot.
For more information, visit the official KB1033604 – Reverting to a previous version of ESXi at https://kb.vmware.com/s/article/1033604.