HP Data Protector Software Performance White Paper

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tape drive can handle (154 MB/s). The Exchange Server backup of test 4 (138.70 MB/s) did not
completely reach the Ultrium tape drive performance of test 1 (154 MB/s). This is because the
data was not always streamed with the same performance. The performance ups were higher,
and if the database was switched (one database backup had finished and the next one started),
the downs much lower.
Table 9. Local backup of Exchange Server 2003 – bottleneck determination
Test Performance (MB/s) Bottleneck?
1. Windows L&TT Tape Write
9
154.00 No
2. DP Null Single (conc.=1) 226.99 No
3. DP Null Parallel (conc.=2) 289.55 No
4. DP Ultrium 960 Parallel 138.70
Yes (Tape)
Local restore of Microsoft Exchange Server 2003
All storage groups were restored from the SCSI-attached Ultrium 960 tape drive.
The performance was only calculated based on the restore time of the storage groups and its
databases. The time for the subsequent transaction log restore and recovery was excluded.
As shown in Table 10, the Exchange Server restore of test 2 (109.61 MB/s) was slower than the
Ultrium tape drive performance of test 1 (156 MB/s). This is because the data was not always
streamed with the same performance. The performance ups were higher and, for example if a
storage group was initialized, the downs much lower.
Table 10. Local restore of Exchange Server 2003 – bottleneck determination
Test Performance (MB/s) Bottleneck?
1. Windows L&TT Tape Read
9
156.00 No
2. DP Ultrium 960 Parallel 109.61
Yes (Tape)
Tuning Data Protector performance for typical files
Data Protector’s backup and restore performance can be improved by modifying its
configuration for backups, devices and media.
Because most users tune their environment for backup performance, only restores are
discussed here. The focus of this white paper is on the most important backup parameters that
are configurable in the GUI. The client-based parameter for the File system tree walk
(see page
38) is not considered.
For simplicity, all tests in this section were executed on HP-UX with the typical files dataset as
created in the section Creating typical files for HP-UX VxFS on page 27
.
Note: In this section, all tests were based on HP-UX typical files with compressibility of data 4:1.
Backup options
Data Protector offers a comprehensive set of backup options for fine tuning. The most relevant
options for performance are:
• Load balancing
• Software compression
• IDB logging level
• Detect Windows NTFS hardlinks
Load balancing
By default, Data Protector automatically balances the load (usage) of devices so that they are
used evenly. Since load balancing is done automatically during backup time, it is not necessary
to manage the assignment of objects to devices, so that all assigned devices stay busy during
9
Tested in the section Evaluating tape and disk drive performance on page 32