NetBackup can process concurrent backup jobs from different policies on the same client only in the following situations:

• More than one storage unit available

• One of the available storage units can perform more than one backup at a time.

You can specify any number of concurrent jobs within the following constraints:

• Number of storage devices

  NetBackup can perform concurrent backups to separate storage units or to drives within a storage unit. For example, a single Media Manager storage unit supports as many concurrent backups as it has drives. A disk storage unit is a directory on disk, so the maximum number of jobs depends on system capabilities.

• Server and client speed

  Too many concurrent backups on an individual client interfere with the performance of the client. The best setting depends on the hardware, operating system, and applications that are running.

  The Maximum jobs per client property applies to all clients in all policies.

  To accommodate weaker clients (ones that can handle only a small number of jobs concurrently), consider using one of the following approaches:

  • Set the Maximum data streams property for those weaker client(s) appropriately. (This property is found under Host Properties > Master Server > Client Attributes > General tab.)

    See Maximum data streams.

  • Use the Limit jobs per policy policy setting in a client-specific policy. (A client-specific policy is one in which all clients share this characteristic).

• Network loading

  The available bandwidth of the network affects how many backups can occur concurrently. Two Exabyte 8500, 8mm tape drives can create up to a 900-kilobyte-per-second network load. Depending on other factors, the load might be too much for a single Ethernet. For loading problems, consider backups over multiple networks or compression.

  A special case exists to back up a client that is also a server. Network loading is not a factor because the network is not used. Client and server loading, however, is still a factor.