For a more efficient backup, the NetBackup media server and the VMware backup host should be installed on the same host.
When creating virtual machines, use the same name for both host name and display name. If the policy's Clients tab still work.option is changed, the existing entries on the policy
VMware recommends that you run no more than four simultaneous backups of virtual machines that reside on the same datastore.
Successful VMware snapshots depend on the following:
The amount of I/O that occurs on the virtual machine datastore. Backups should be scheduled when relatively little I/O activity is expected. Reducing the number of simultaneous backups can also help.
Limit access to the datastore per policy: Use theattribute in the NetBackup policy.
Limit access to the datastore globally (across all policies): Use the Host Properties Resource Limit screen.
The design of the I/O substructure that is associated with each virtual machine datastore. For correct I/O design and implementation, consult your VMware documentation.
Make sure that the VMware backup host has enough memory to handle the number of simultaneous backups that occur.
Include in a single NetBackup policy those virtual machines that use the same datastore. This practice lets you control the amount of backup-related I/O that occurs per datastore, to limit the backup effect on the target virtual machines.
NetBackup supports multiple backup hosts. When a single backup host is saturated with a backup process, another backup host can be added to increase backup throughput.
If a VM's disks are accessible to multiple ESX hosts, the disks can be accessed for backup or restore through any of the ESX hosts. The ESX host may or may not be the ESX host where the virtual machine is running or registered. All of the following must be accessible to each other and should have DNS configured:
Upgrade to the latest version of VMware vSphere or Virtual Infrastructure.
See the Symantec white paper titled NetBackup for VMware Best Practices Guide.