Data Protector Deduplication Guidelines - HP 12000 Design Manual

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 6.1 1 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.
Patch all clients running the Oracle database backup agent so the VLS will correctly identify
incremental backups (instead of treating them as full backups). The latest Oracle patch for
Data Protector 6.1 1 is Patch DPWIN_00486.
Oracle RMAN Scripting: See
Tape Retention Planning: Create media pools based on retention period. Mixing retention
periods will prevent cartridge expiration reclamation and leads to poor storage utilization.
Space used for the shorter retention backup is not reclaimed until all backups on the tape are
expired. That is, the backup application cannot reuse/reformat the tape until all backups have
exceeded their protection period. The backup application will not reuse expired cartridges
until all spare formatted virtual cartridges are used, so in this case HP recommends either
removing unneeded virtual cartridges or creating a script on the cell server to automatically
reformat expired cartridges on a regular basis.
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.
Different backup job names for the same data: Some Data Protector configurations have
different backup job names for backing up the same data due to having different retention
times for the different backup types (for example, different job names for full backups vs.
incremental backups, or different names for weekly full backups vs. monthly full backups).
However, because the backups have different backup job names they will not deduplicated
against each other even though they contain exactly the same data. To address this, VLS
firmware versions 3.3.0 and higher include a GUI option called "Edit Data Protector
Configuration" (in the System Maintenance screen). This option allows you to enter suffixes
that will be stripped off the end of the Data Protector backup jobs names when they are
deduplicated. For example, if you have a full backup called BACKUP1_F and an incremental
backup of the same data called BACKUP1_I, you can enter _F and _I in the Edit Data
Protector Configuration and the incremental backups will deduplicate against the full backups.
Similarly, having a weekly full backup called BACKUP2 (WEEKLY) and a monthly full backup
Oracle RMAN Scripting for details.
HP Data Protector 137