Media servers as backup or discovery hosts
NetBackup for VMware uses a special host that is called a VMware backup host. The backup host is a NetBackup client that performs off-host backups of the virtual machines. The backup host must have access to the datastores of the virtual machines. The backup host reads the data from the datastore and sends it over the network to the media server. The media server backs up the data to storage.
NetBackup also uses a discovery host. For the policies that automatically select virtual machines, the discovery host filters virtual machines according to the rules in the policy Query Builder. The discovery host returns a list of virtual machines to be selected for backup.
NetBackup can use media servers as backup hosts and as discovery hosts.
Media servers acting as backup or discovery hosts can provide the following advantages:
Host redundancy: If one media server goes down, another media server takes over.
Faster backup: The media server can read the data from the datastore and send the data straight to the storage device. Without media server access to storage devices, an ordinary backup host must send the backup data over the local network to the media server.
Figure: Backup media servers shows a group of media servers that can also act as backup or discovery hosts. The media servers can discover virtual machines for automatic selection, and perform off-host backups and send the backup data directly to storage.
You can combine the flexibility of backup media servers with a standard feature of NetBackup: storage unit groups. Create a storage unit group that contains the storage units that your media servers can access. Any of the media servers can operate as a backup host.
Note the following requirements:
To configure media servers as backup hosts: Set the policy VMware backup host field on the VMware tab to Backup Media Server.
See VMware backup host.
To configure media servers as discovery hosts: Set the policy NetBackup host to perform automatic virtual machine selection field on the Clients tab to Backup Media Server.