HP StorageWorks 6000 HP StorageWorks VLS and D2D Solutions Guide (AG306-96028, - Page 194

5. Create an echo copy pool for the VLS2 replication library, with the library on VLS1 as the source. Automigration will automatically create the replicating virtual cartridges on VLS1 in the spare slots configured in step 1. During the automigration window you created, backups already copied to replicating virtual cartridges on VLS1 will automatically be copied over to VLS2. If you back up to a non-automigration tape in VLS1, then nothing else happens. To the backup application, there is just one target library, though it contains both replicating and non-replicating tapes. It is easy to put the replicating tapes into a different media pool in the backup application, and simply configure the backup jobs to use either the replication media pool, or the non-replication media pool. In either case, all the backup jobs go to the one, shared destination library. NOTE: For cross-replication you can create the reverse configuration. For example, create another large library on VLS2 for its backups, and create a small replication library on VLS1 that is visible to the back-end ports of VLS2. Detailed Backup Application Guidelines for VLS To achieve full performance benefits from the VLS, you may need to modify your enterprise backup application configuration (for example, to take advantage of the fact that you can create many more virtual tape drives than a physical tape library holds). If you have enabled deduplication, you may need additional changes in your enterprise backup application to take full advantage of this capacity optimization technology. Follow these guidelines before you begin deduplicating your data or some data may not deduplicate efficiently. HP Data Protector This section includes both general and deduplication guidelines as well as other useful information for HP Data Protector. Data Protector General Guidelines The following Data Protector guidelines apply to a VLS regardless of whether deduplication is enabled or disabled: • Tape block size: set the tape block size to 256 KB in the Drive Properties of the virtual tape drives configured in Data Protector. • Multiple paths to tape devices: in an environment with shared tape devices, there may be "Mul- tiPath" devices within Data Protector (where there are both direct and indirect paths to the same shared tape drive). To ensure optimal performance, verify that the direct path is used for backups. • Data Protector media pool policy: the recommended media pool policy is "Loose" and "Appendable." This prevents dedicating specific cartridges to specific backup jobs which results in inefficient media usage and can also cause significant impact to VLS deduplication because it does not consistently fill tapes. • Disable multiplexing: set the concurrency to 1 (default is set in the Drive Properties, and can also be set in the backup specifications), because multiplexing is not recommended for virtual libraries due to the performance impact on restores and on deduplication. Because you can create additional drives easily in the virtual library and allocate them to Media Agents as necessary, sufficient backup streams can be concurrently written without requiring multiplexing. • Disable client backup compression. 194 Virtual Library Systems