An ESXi system grants access to its resources when a known user with appropriate permissions logs on to the system with a password that matches the one stored for that user.

You can use the vSphere SDK for all user management tasks. You cannot create ESXi users by using the vSphere Web Client.

You can use the vicfg-user command to create, modify, delete, and list local direct access users on an ESXi host. You cannot run this command against a vCenter Server system.

Important: Starting with vSphere 5.1, you can no longer manage groups with vicfg-user.