HP Data Protector Software Performance White Paper

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Figure 63 shows that different buffer sizes resulted in the same CPU load (12%). This was
expected because there was only a small performance difference, as shown in Figure 62.
Figure 63. CPU load of Exchange Server 2003 local backup to Ultrium 960 with buffer size 32 – 1,024 KB
Tuning recommendations
Due to the high number of variables and permutations, it is not possible to give specific
recommendations that will fit all user requirements and affordable investment levels. However,
consider the following when trying to improve backup or restore performance:
• Ensure that the server is sized for the backup requirements. For example, fast tape devices
like an HP StorageWorks Ultrium 960 tape drive should be placed on a dedicated 133-MHz
PCI-X bus and not share the bus with other HBAs, such as a Gigabit network adapter.
• During high performance backups, Windows memory problems could occur. This is a general
Windows kernel problem and applies to almost all backup applications — including
NTBACKUP.
The Data Protector error message looks like:
[Major] From: [e-mail] "G:" Time: 29.03.2005 19:08:57
[81:78] G:\1\file67108864_000003
Cannot read 57256 bytes at offset 0(:1): ([1450] Insufficient system
resources exist to complete the requested service. ).
Note: It is advisable to follow the instructions in Microsoft article Q304101, which explains the
circumstances that can lead to this error and settings for avoiding memory problems. The
article is here:
http://support.microsoft.com/default.aspx?scid=kb;en-us;Q304101
• Ultrium 960 tape drives are best used with a block size of 256 KB as described in Getting the
most performance from your HP StorageWorks Ultrium 960 tape drive white paper
(downloadable from http://h18006.www1.hp.com/storage/tapewhitepapers.html
).
• For all backups using Ultrium drives, it is recommended to keep the software compression
option disabled when configured with Data Protector.
• If backup devices are SCSI- or SAN-attached, software compression should be disabled. On
the other hand, software compression could make sense when executing network backups
MS Exchange Server 2003
Buffer Size 32 - 1,024 KB
CPU Load of Local Backup to Ultrium 960
12%
12%
12%
12%
12%
12%
0%
10%
20%
30%
40%
50%
60%
70%
80%
90%
100%
32 64 128 256 512 1,024
Buffer Size (KB)
CPU Load