System monitoring

The modified top utility that comes with the LTP test suite was used as a system monitoring tool. top provides an ongoing look at processor activity in real time. The enhanced top utility has additional functions that can save snapshots of top results to a file and give the average summary of the resulting file, including information such as CPU, memory, and swap space utilizations.

In our tests, snapshots of system utilization (or top output files) were taken every 10 seconds and saved to result files. In addition, snapshots of system utilization and LTP test output files were taken daily or weekly to have data points to determine whether systems were degrading during long-period runs. This function was controlled by cron jobs and scripts.

Before testing
All selected testing systems had hardware configured as similarly to each other as possible. Extra hardware was removed to reduce potential hardware failure. Minimum-security options were selected during image installation. At least 2 GB of disk space was reserved for storing the top data files and LTP log files.

Note that this is a testing scenario; in real life, users would be well advised to keep security settings at much higher than minimum.

During testing
The system was left undisturbed for the duration of the tests. Occasional access of the system to verify that the test was still executing was acceptable. Verification included using the ps command, checking top data, and checking LTP log data.

After testing
When the test completed, the system monitoring tool top was stopped immediately. All top data files, including daily or weekly snapshots and LTP log files, were saved and processed in order to provide data for analysis.