HP Data Protector Software Performance White Paper

Local backup of small files

The small files were saved to the SCSI-attached Ultrium 960 tape drive.

Table 2 shows that file systems with millions of small files were not able to fully use the Ultrium

960 tape drive. The file systems were the bottleneck for both operating systems. This also had

some impact on Data Protector because the large amount of file information that had to be

written to tape and into Data Protector’s IDB resulted in an additional performance loss of 6.04

MB/s for Windows (test 3 with 29.02 MB/s, test 5 with 22.98 MB/s = 6.04 MB/s). See the section

Data Protector IDB Considerations on page 39

for further details.

The CPU load of tests 4 and 5 was higher for Windows (61%) than for HP-UX (25% and 16%).

This is the result of the inefficient Windows NTFS file system when dealing with millions of small

files.

Note: For Windows tests 4 and 5, the first file system tree walk was disabled which improved

the overall performance. Without this, the performance would have been even worse.

Table 2. Local backup of small files – bottleneck determination

Test Performance (MB/s) CPU Load Bottleneck?

1. Windows L&TT Tape Write

154.00 - No

2. Windows HPReadData Single

10.59 -

Yes (File System)

3. Windows HPReadData Parallel

29.02 -

Yes (File System)

4. Windows DP NULL Parallel 22.54 61% No

5. Windows DP Ultrium 960 Parallel 22.98 61% No

1. HP-UX L&TT Tape Write

158.54 - No

2. HP-UX HPReadData Single

24.41 -

Yes (File System)

3. HP-UX HPReadData Parallel

53.08 -

Yes (File System)

4. HP-UX DP NULL Parallel 50.50 25% No

5. HP-UX DP Ultrium 960 Parallel 48.76 16% No

Recommendation: If backing up file systems with millions of small files, parallel backups with a

higher concurrency are recommended. These kinds of file systems are very slow and should be

multiplexed. Instead of the fast Ultrium 960 tape drive, consider using a slower Ultrium tape

drive or backup-to-disk technology.

Tested in the section Evaluating tape and disk drive performance on page 32