3 fast tape devices, consider using 3 dedicated network links between system_A and system_B.

•Load Balancing

Using this Data Protector feature, Data Protector dynamically determines which object (disk) should be backed up to which device. Enable this feature, especially to back up a large number of filesystems in a dynamic environment. For more information, see “How load balancing works” on page 156.

Note that you cannot predict to which media a particular object is written.

Configuring backups and restores

Any given infrastructure must be used efficiently to maximize performance. Data Protector offers high flexibility to adapt to the environment and the desired way to operate backups and restores.

Software compression

Software compression is done by the client CPU when reading data from a disk. This reduces the data that is sent over the network, but it requires significant CPU resources from the client.

By default, software compression is disabled. Use software compression only for backups of many machines over a slow network, where data can be compressed before sending it over the network. If software compression is used, hardware compression should be disabled since trying to compress data twice actually expands the data.

Hardware compression

Hardware compression is done by a device that receives original data from a Drive Server and writes it to media in the compressed mode. Hardware compression increases the speed at which a tape drive can receive data, because less data is written to the tape.

By default, hardware compression is enabled. On HP-UX systems, enable hardware compression by selecting a hardware compression device file. On Windows systems, enable hardware compression during device configuration. Use hardware compression with caution, because media written in compressed mode cannot be read using a device in uncompressed mode and vice-versa.

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Planning your backup strategy