How to achieve over 2 TB/hr network backup with Integrity entry-class servers running HP-UX 11i v3

combination for backup utility tunable settings is 32 buffers and 256KB I/O blocks. Again, because

optimal tuning may vary from one backup server environment to another, similar tuning analysis

should be performed for each specific environment.

4Gb FC HBA port limit testing

Characterization and limit stress testing of the 4Gb FC port involved connecting tape devices in scale-

up succession to a single 4Gb FC port until obtaining the maximum port throughput. For each tape

device added, two additional clients were added to direct data to it. Each client provided four data

streams. Figure 5 shows the results of the stress testing.

Figure 5: 4Gb FC HBA port throughput limit testing

The results show that a single LTO-4 tape device connected to a 4Gb FC port was able to attain an

average of 225 MB/s. When a second tape device is added to the same 4Gb FC port, the total

throughput achieved was about 334 MB/s, or an average of 167 MB/s per device. Scaling up to

four LTO-4 tape devices resulted with a total maximum throughput of about 390 MB/s. This is very

close to the maximum 4Gb FC port throughput of 410 MB/s that was achieved with other HBA

performance-optimized tests. For more information about 4Gb FC HBA performance and scaling,

see the “AB379B – PCI-X Dual Channel 4Gb/s Fibre Channel Adapter” white paper at the following

location:

http://bizsupport1.austin.hp.com/bc/docs/support/SupportManual/c02019292/c02019292.pdf

While these tests identified the port throughput limit by using four LTO-4 tape devices connected to a

single 4Gb FC port, this is not a recommended configuration. To achieve optimal device throughput,

connect no more than two LTO-4 tape devices per 4Gb FC port. A single 4Gb FC port does not have

enough I/O throughput bandwidth to sustain concurrent optimal throughput to more than two LTO-4

tape devices.

100

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1 tape/2

clients

2 tapes/4

clients

3 tapes/6

clients

4 tapes/8

clients

Data Throughput (MB/s)