HP StorageWorks 9000 HP StorageWorks VLS and D2D Solutions Guide (AG306-96028, - Page 195
Data Protector Deduplication Guidelines, Config\Server\Options\global
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Data Protector Deduplication Guidelines In addition to the Data Protector general guidelines, the following guidelines apply to a VLS with deduplication enabled: • Patch all Windows clients: HP Data Protector on Windows clients requires a software fix to eliminate 56 KB file fragments that diminish deduplication performance on VLS and D2D products. The fix depends on your version of Data Protector: • DP 6.0: install the patch DPWIN_00426 (or later patches). Download the patch from the HP website on the Data Protector version 6.0 "Download drivers and software" page. • DP 6.1: included in the 6.11 service pack. If this is not yet available, request SSPNT610_012 (which you can automatically deploy to all Windows Disk Agent clients) through the Data Protector support channel. • Disable multiplexing in Oracle RMAN backups: In the VLS firmware version 3.3.0 (or higher) the scripting requirements for Oracle data files have been relaxed, so it is no longer mandatory to assign prefix naming conventions to Oracle data files to make sure the data is properly deduplicated. The minimum requirement for RMAN to deduplicate efficiently is to disable multiplexing (where you have multiple RMAN streams concurrently writing to the same drive). You can disable multiplexing by setting concurrency to 1 in Data Protector and setting FILESPERSET=1 for each database backup in the RMAN scripts (not needed for archive logs or control files). You can define additional channels to increase the number of parallel backup processes running with FILESPERSET=1 to generate the same RMAN performance as before, so that each stream goes to a different virtual tape drive. The following RMAN settings will not deduplicate because they always generate totally unique data every backup: • Incremental backups • RMAN compressed backups • RMAN encryption NOTE: If you had previously configured the prefix naming conventions in your Oracle RMAN scripts, this will continue to deduplicate efficiently with the firmware version 3.3.0 (or higher), but you should ensure that multiplexing is disabled as well. If you wish to remove the prefix naming conventions, you will need to rename the backup job name in Data Protector. (New backup jobs will not deduplicate against the previous jobs with the different job name.) • Allocate Unformatted Media First: If you have deduplication enabled, you should disable the "Allocate unformatted media first" option in the media pool. You must also set the global variable InitOnLoosePolicy=1 defined in the global file and the Data Protector services must be restarted for the global variable to take effect. In HPUX the file is located in /etc/opt/omni/server/ options/global, and in Windows the file is located in C:\Program Files\OmniBack\ Config\Server\Options\global. These settings prevents Data Protector from using all available blank cartridges for backups before it starts overwriting expired/scratch cartridges; creating too many virtual cartridges results in the device disk capacity filling up. • Interactive backups will not deduplicate: If you edit a Data Protector backup specification and then manually run it from the GUI without saving it, the backup session will run with a backup specification name of 'Interactive' and therefore will not deduplicate. This is because deduplication correlates backup versions using the backup specification name. • Full and incremental backups with different names: Some Data Protector configurations have different backup job names for full backups and for incremental backups (for example, to have dif- HP StorageWorks VLS and D2D Solutions Guide 195