HP Data Protector Software Performance White Paper

48
Network restore of small files
The small files were restored via the network (Gigabit Ethernet) from the remote backup server
and its SCSI-attached Ultrium 960 tape drive.
For Windows, Table 8 shows that the tape device did not read faster than 156.00 MB/s, and test
2 shows that the disk device can write with 19.94 MB/s. But test 3 resulted in just 3.66 MB/s
restore performance for Data Protector. The bottleneck was the file system, which was very
busy during the recovery. Millions of small files were written back with their original names and
file attributes. The tape device was always in start/stop mode.
Note: For Windows, test 4 with parallel writes to file systems was not possible due to problems
with an overflow of the Windows system paged pool. See the section Disk write performance
on
page 35 for further details. For that reason, HP-UX test 4 was skipped.
Table 8. Network restore of small files – bottleneck determination
Test Performance (MB/s) Bottleneck?
1. Windows L&TT Tape Read
8
156.00 No
2. Windows HPCreateData Single
8
19.94
Yes (File System)
3. Windows DP Ultrium 960 Single 3.66
Yes (File System)
4. Windows DP Ultrium 960 Parallel - -
1. HP-UX L&TT Tape Read
8
160.71 No
2. HP-UX HPCreateData Single
8
51.41
Yes (File System)
3. HP-UX DP Ultrium 960 Single 20.18
Yes (File System)
4. HP-UX DP Ultrium 960 Parallel - -
Backup and restore of Microsoft Exchange Server 2003
The Microsoft Exchange Server was principally tested for backup performance. Four storage
groups with one 50 GB database each were saved to the SCSI-attached Ultrium 960 tape drive.
Other scenarios were not tested, for example with multiple databases per storage group,
because they would not significantly change the performance results (MB/s). Multiple databases
within one storage group are backed up one after the other.
Note: Multiple storage groups are backed up in parallel, but multiple databases (stores) within a
storage group only sequentially.
Basic Microsoft Exchange Server 2003 test tools for backup and restore were not available
during the creation of this white paper, so only L&TT and Data Protector were used for testing.
Data Protector configuration parameters
The maximum device concurrency for backing up the Exchange Server data is two. A higher
concurrency would use too much of the Exchange Server’s resources and would not improve
the backup performance.
Recommendation: The recommended device concurrency for backing up the Exchange Server
data is two for devices connected directly to the server, and one for devices connected
remotely.
The buffer size is based on the formula buffer size = concurrency x 16 KB. The minimum buffer
size is 32 KB, which is the default buffer size as well.
Local backup of Microsoft Exchange Server 2003
All storage groups were saved to the SCSI-attached Ultrium 960 tape drive with the default
configuration values for concurrency (2) and backup buffer size (32 KB).
The performance was only calculated based on the backup time of storage groups and their
databases. The backup time for the subsequent transaction log backup was excluded.
In Table 9, test 2 (226.99 MB/s) and test 3 (289.55 MB/s) demonstrate that the Exchange
Server integration of Data Protector was able to provide more performance than the Ultrium 960
8
Tested in the section Evaluating tape and disk drive performance on page 32