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

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One-gigabit Ether port limit testing
To determine the maximum backup data I/O throughput that can be expected for each client over a
single 1GbE NIC port, multiple backups cycles were performed, increasing the number of parallel
backup data streams and, for each cycle, rerunning the tests with different backup utility tunable
settings for the number of buffers and block size: first with 8 buffers and 64KB blocks, and then with
32 buffers and 256KB blocks. Figure 3 shows the results of these tests.
Figure 3: Results of 1GbE port backup throughput stress tests
As shown, the tests demonstrate that the maximum data I/O rate for a single client using a single
1GbE port is about 113 MB/s, which is also the maximum link speed for a 1GbE port. Tests show
this throughput rate can be achieved with three concurrent data streams on the client; however, four
parallel data streams were used from each client in subsequent tests to make allowances for
temporary lags in any individual data stream resulting from small files, disk agent delays, and so
forth. Four data streams better assure consistent maximum client data-transfer rates to the backup
server.
These tests demonstrate that for one or two data streams per client, the optimal backup utility tuning
setting for data throughput over the 1GbE NIC port is the tuning combination of 8 buffers and 64KB
I/O blocks. For three or more data streams, both tuning combinations perform equally. However, the
tests for determining optimal tape drive throughput (described in the “HP StorageWorks Ultrium 1840
LTO-4 limit testing” section) reveal that the tuning combination of 32 buffers and 256KB IO blocks is
more optimal for overall throughput to the LTO-4 tape devices.
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Data Throughput (MB/s)
Number of Data Streams to One LTO-4
8 buff/64KB blks
32 buff/256KB blks