HP tape drive performace testing configuration

Version 1

    Customers sometimes ask why they are not able to obtain the tape drive performance advertised in the sales literature.

    (Copy and paste into your response as needed)

    Extract from DVT report

    " Top Level Read/Write Transfer Rates Objective
    Verify top line data rates at with various compressibility data with a variety of transfer and block sizes.

    Top Level Read/Write Transfer Rates Description
    The test software used to measure the top performance test is in-house HP test software that allocates a block of memory, and then fills that memory with data of a known compressibility. It then sends that data to the tape drive using a repeating loop of "write" system calls, timing the overall time taken to transfer the data. After writing the data, the tape was rewound and timed for doing the same but this time using a repeating loop of "read" system calls to read back the data on the tape.
    In no case was data actually taken off a disk spindle. This was a deliberate choice to ensure that the disk source was not a bottleneck in the system and we could therefore verify the theoretical maximum throughput of the drive.
    In addition to verifying top line performance the tools also allow the testing of the drive with substantially below optimum "