Where to Install the Agent

As a general best practice, you must install the agent on the following locations:

VMware environments--on the backup proxy systems and in the VMs that you want to protect.
Hyper-V environments--on the Hyper-V host systems and in the VMs that you want to protect.

However, the backup mode that you require for your backups determines where you must install the agent.

Note: For more information about backup modes, see How Global and Local Backup Modes Work.

The following table identifies the type of backup modes that you require and where you must install the agent.

Backup Mode Specified	Hyper-V Host System	VMware Backup Proxy System	Hyper-V VM	VMware VM
File mode	Required	Required	Required	Not required
Raw (full VM) mode and Allow file level restore is not specified	Required	Required	Not required	Not required
Raw (full VM) mode and Allow file level restore is specified	Required	Required	Required	Not required
Mixed mode and Allow file level restore is not specified	Required	Required	Required	Not required
Mixed mode and Allow file level restore is specified	Required	Required	Required	Not required

Be aware of the following considerations:

You must register one license for each VM that you are protecting with Arcserve Backup. All licenses must be registered on the primary server or stand-alone server.
You can register an agent license for each virtual machine, hypervisor (host), or per-socket. The type of license that you can use in an environment depends on the number of virtual machines that are protected or the number of sockets per host.
For Raw (full VM) backups, the agent is not required to be installed on the VMware virtual machines to provide file level restore. File level restore is automatically provided from raw backups. However, the agent is required to be installed when performing a restore. For more information, see Where to Install the Agent.
Note: This feature is available when you upgrade to the Arcserve Backup r17 release.
In r16.5, you can run incremental backup jobs for Mixed mode backups through VMware VDDK on the proxy server or through the agent that is installed on the virtual machine. When you upgrade to the Arcserve Backup r17 release; the agent is no longer required to be installed on the virtual machine; therefore the only option available to run an incremental backup job for Mixed mode backups is through VMware VDDK on the proxy server.