DAT72 performance

[Ian Lochray]

I have two HP servers each running Windows 2003 with HP DAT 72 tape drives.
They are both backed up everey night using ntbackup.
One backs up 58Gb in 1.5 hours but the other takes 19.5 hours to back up 59Gb.
Does anyone know why the second one might take so long?

[Torsten. · Accepted solution]

I would suggest to install LTT and pull a support ticket to get more information

http://www.hp.com/support/tapetools

Could be a bad drive or bad cable/terminator for example.

[Ian Lochray]

What an excellent tool. I have downloaded it and run some tests which have not found any problems.

As it did not find any issues, I am suspicious that the problem lies with the performance of the disk array it is backing up. Is there a similar tool to test disk performance?

[Torsten.]

Try the "sys perf" option within this tool.

[Rob Leadbeater]

Hi Ian,

What sort of data are you backing up ?

It will probably take a lot longer to backup 59GB worth of small files compared to a single 58GB file...

Cheers,

Rob

[Ian Lochray]

Torsten,
the sysperf tool will only let me test the tape drive, not the disks.

I completed the tape tests and they say that the drive is OK and working at 83% capacity.

Rob,
the files are very similar so this isn't the problem.

[Torsten.]

Did you use "sys perf" or "dev perf"?

Sys perf will read from disks to measure performance.

from the help text:

Performing the System Performance Backup Performance Test
This test reads data from up to four separate locations on the file system. The reads are concurrent and simulate up to four concurrent backup data streams. The performance of these reads is measured and reported in the System Performance Results tab. Use this test to measure the performance of the file system to be used for backup. Use this test in conjunction with the Drive Performance Test to identify performance bottlenecks in the system. This test is read-only and can be safely run on backup source data.

Default location of this text on your locale disk:

file:///C:/Program%20Files/HP%20StorageWorks%20Library%20and%20Tape%20Tools/catalogs/enu/help/PerformingSysPerfBackupPreTest.html