Advanced Backup to Disk Performance White Paper

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.