In this screen, Arkeia hosts can be promoted to Media Servers.
A list of available hosts appears in the right side panel. The left side panel contains the list of media servers currently declared. Since the backup server is always a media server by default, it will appear in this list.
The hosts listed are automatically Arkeia clients because the Arkeia client software is installed on them. If you wish to include in a Drivepack a storage device attached to one of the hosts, then that host must be "promoted" to a media server in this screen by highlighting it and clicking on the left arrow, moving it into the list of media servers.