Define a Limit to the Quantity of Concurrent Backups

You can define a limit to the quantity of backup jobs that run concurrently. This capability lets you optimize the performance of the virtual machine proxy server in your backup environment. By default, Host-Based VM Backup can run up to ten backup jobs concurrently. In environments that contain many virtual machines that are associated with a virtual machine proxy system, a high quantity of concurrent backups can have an adverse effect on network and backup performance.

Note: When the quantity of concurrent jobs exceeds the defined limit, the jobs that exceed the limit enter a job queue.

Note: If the maximum number of concurrent VMware backup jobs exceeds the ESX server connection limit, communication failure can occur between the ESX server and the backup proxy, and the file system of the ESX server data store can remain locked. In such cases, restart the ESX server or migrate the locked virtual machine to another data store to unlock the VM. For more details, refer to the VMware document (VMware KB:1022543).

Follow these steps:

1. Log in to the CA ARCserve Unified Data Protection virtual machine proxy system.
2. Open Windows Registry Editor and browse to the following key:

   HKEY_LOCAL_MACHINE\SOFTWARE\CA\ARCserve Unified Data Protection\Engine
   

3. Locate the following key:

   VMMaxJobNum
   

   Note: The VMMaxJobNum key is already created and the default value is 10.

4. Right-click VMMaxJobNum and click Modify on the pop-up menu.

   The Edit String dialog opens.

5. In the Value Data field, specify the quantity of backup jobs that you want to allow to run concurrently.

   Minimum limit--1

   Maximum limit--none.

   Default--10

6. Click OK.

   The limit is defined.

7. Restart the CA ARCserve Unified Data Protection Agent (Windows) service.

The limit of concurrent backup jobs is defined.