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Performance assessment tools, Optimizing performance – HP StoreEver DAT Tape Drives User Manual

Page 40

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Diagnostic Tools and Performance

40

• Run tests: allows you to run proactive tests on your drive, such as the drive assessment test,

which will verify the functionality of your drive in around 20 minutes. HP recommends

running this test before calling HP Support. You will need to provide a ‘trusted’ cartridge that

can be written to during this test.

• Generate a support ticket: this is a full dump of the drive logs along with interpretation and is

used by HP Support to learn about the condition of your drive. Most useful is the device

analysis section which is the output from approximately 20 rules forming a comprehensive

analysis of the health of your drive. These rules may give advice such as cleaning the head

or trying a different tape if issues are found. The support ticket can be sent to HP Support for

further analysis.

• Run the performance tests: the tests to measure the write/read performance of your tape

drive and the data generation rates of your disk subsystem are also integrated into Library &

Tape Tools. Use these tests to find the performance bottleneck in your system.

Performance Assessment Tools

You can use our free, standalone performance assessment tools to check tape performance and test

whether your disk subsystem can supply data at the maximum transfer rate.
The tools are located online at

www.hp.com/support/pat

along with a complete guide to

understanding the performance needs of your backup system and recommendations on finding and

fixing performance issues. In nearly all cases when performance is not as expected, it is the data

rates of the disk subsystem that cause the bottleneck. Please follow the guide and try the tools before

calling HP Support.
Note that the performance tools are also integrated into HP Library & Tape Tools, which is available

both online (

www.hp.com/support/tapetools

) and on the CD-ROM supplied with your tape drive.

Optimizing performance

Various factors can affect tape drive performance, particularly in a network environment or if the

drive is not on a dedicated bus.
If your tape drive is not performing as well as expected, consider the following points before

contacting HP Support at

www.hp.com/support

.

Is the tape drive connected to a USB 2.0 port and is it the only device (other than a keyboard or

mouse) using the USB bus? See

Verifying USB installation for optimum performance

” on

page 42.

Have you installed the correct device drivers for your operating system and backup application?

See

Install drivers

” on page 9.

Are you backing up across a network? The network load may be affecting the speed of transfer

or your backup application may only be appropriate for a single-server environment.

Is the backup application writing buffers at the correct speed? You may need to tune the transfer,

buffer and block size settings to optimize the speed that the application writes data to the tape

drive. HP StorageWorks DAT tape drives have an internal buffer of 8 MB.