You can use vSphere Auto Deploy to provision an ESXi host, and set up a host profile that causes the host to store the ESXI image and configuration on the local disk, a remote disk, or a USB drive.

Subsequently, the Auto Deploy server continues to provision this host. If the Auto Deploy server is not available, the host uses the image on disk.

See Using Auto Deploy for Stateless Caching and Stateful Installs.