Computer Associates ARB6002700WF0. ..... Administration Guide - Page 86

Multistreaming Multistreaming Note: To use multistreaming, you must install the BrightStor ARCserve Backup Enterprise Module. Multiple streaming offers you the advantage of using all the available tape devices on the system by splitting a single backup job into multiple jobs using all the tape devices. As a result, it will increase the overall backup throughput compared with the sequential method. You can use all of the devices or you can specify a single group of devices. If the BrightStor® ARCserve® Backup Tape and Optical Library Option is installed and the group with the library is selected, multiple streaming uses all library devices. If the BrightStor ARCserve Backup Tape and Optical Library Option is not installed, you can put devices into separate groups. For a changer, the total number of streams (slave jobs) that are created depends on the number of tape devices. For a single tape drive device, the total number of streams depends on the number of device groups. Multistreaming is performed at the volume level for regular files (two volumes can run simultaneously on two separate devices), and at the database level for local database servers. Multiple streaming is performed at node level for Preferred Shared Folder, remote database servers, and Windows Client Agents. You can have only as many jobs running simultaneously as the number of devices or groups that are on the system. With the Multi Stream option, one master job is created that will trigger slaves jobs for as many volumes as you have. When a job is finished on one device, another job is executed until there are no more jobs to run. Some characteristics and requirements of multiple streaming are: ■ Multistreaming always requires a media pool selection to prevent the tapes from being overwritten (for Windows only). ■ Separate tape devices should be configured in separate groups for regular drives, however for changers, they can be configured to be in the same group. For UNIX, separate groups are required for the multistreaming option. ■ Multistreaming works with Rotation and GFS jobs. ■ Canceling the master job cancels all of the slave jobs. For Windows, canceling and monitoring is checked between jobs for performance considerations. ■ Pre and post operation and comments is supported at the master job level. Pre/post operations are not performed for slave jobs. 3-24 Administrator Guide