Summary and Conclusions

This white paper briefly describes performance-related information for HP OpenView Storage Data Protector 5.5 and the Advanced Backup to Disk feature:

•The test environment is able to provide a good performance with a low usage of CPU and memory resources. Only a high number of small files cause I/O problems.

•Disk staging acts as a buffer allowing media drives to operate at maximum speeds and provide the option to do automatic data replication during off-peak hours. This technique is highly recommended when backing up numerous small files to prevent poor transfer rates to tape drive.

•Disk technologies (SATA, SCSI) and RAID levels could have major performance differences.

•RAID 0 should not be considered due to missing fault tolerance features. The backup device – in this case disk – must be very reliable. In general, backups should be available for disasters and selective restores. If a disk fails during the backup or between the backup and the restore (disks always spin, tapes not), backup data would be lost.

•Backup and restores of typical files could be faster with tape technology than with disk technology (file library).

•Single file restores are executed with an excellent performance by disk technologies. This is very helpful for selective file restores (particularly multiple times) where time is an important issue. No tape must be loaded and positioned which is a major advantage against tape technologies.

•The performance can be determined by the performance tools described in chapters HPReadData and Library and Tape Tools. It is recommended to check the disk performance before Data Protector is configured. In most cases, an optimized disk array configuration has more impact than default parameter changes of Data Protector.

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