When populating the policy list "Backup Host" in a VMware policy population of this list can be slow.
This is caused by the GUI operation polling each media server to ascertain the O.S & NetBackup version
of each media server, when the O.S and NBU version of the Media Server has been determined and is
compatible as a Backup Host (RHEL, SUSE or Windows + Compatible NBU Version) this list is populated regardless
of whether or not the media servers have access (either credentials or physical access) to the vCenter & ESX
servers.
On large sites or sites with media servers over a WAN link this process can take a long time and can be further
exacerbated by other factors such as long ARP and DNS lookup times.
Requirement for this change is to allow the backup operator to specify which machines should be used as Backup
Hosts and not have the GUI blindly poll every media server to confirm compatibility. Manually specifying which machines
are Backup Hosts should remove this delay and improve user experience.