Has anybody looked into the accuracy of tape drive throughput reports?
Report Templates > Disk & Tape Device Activity Reports > Tape Drive Throughput
A long running backup ran for over nine hours had six streams running at ~18 MB/s each into the same drive in parallel, total throughput is about 108MB/s. In the tape drive throughput that tape drive never exceeded about 5MB/s (actual 40716Kb/s) when grouped by "hour of the day", plus I would expect the report to show the tape drive and media server combination reporting throughput over an extended period. The period indicated in OpsCenter is substantially shorted than what NetBackup reports in the activity monitor. Usually were there is one obvious error in reporting there probably others. All the throughput rates are in Kb/s even if they were in KB/s that would not be close to reality.
According to the manual they are calculated on "Advanced averaging logic is used to determine the throughput values for each cell in the report. The averaging is done at an image fragment level ensuring granularity and precision in calculations." - marketing ?
