Iometer disk I/O monitor

If you want to check out disk performance, the Iometer disk utility can show you exactly what's happening.

Sometimes you sit down at a machine to carry out some routine maintenance and wonder whether its disk drive is powered by electricity or a small hamster running round a wheel. Knowing why a drive is taking forever to copy a file or why the drive light is permanently on can be tricky, but a free utility called Iometer can help. This utility was originally developed by Intel but is now maintained as a free, open-source performance test tool.

Iometer measures performance under a controlled load, and is both a workload generator and a measurement tool, so it performs I/O operations in order to stress the system, and examines and records the performance of its I/O operations and their impact on the system. It can be configured to emulate the disk or network I/O load of any program or benchmark, or can be used to generate entirely synthetic I/O loads. It can generate and measure loads on single or networked systems. Iometer can be used for measurement and characterisation of: 

• Performance of disk and network controllers.
• Bandwidth and latency capabilities of buses.
• Network throughput to attached drives.
• Shared bus performance.
• System-level hard drive performance.
• System-level network performance.

Iometer has a graphical interface that you use to configure the workload, set operating parameters, and start and stop tests. It collects the test results and produces the reports for analysis. Iometer calls a command line application called Dynamo that is the workload generator. Dynamo performs I/O operations and records performance information, then returns the data to Iometer.

You can set Iometer to mimic different types of disk use to simulate different types of machines such as a desktop PC, database server, or file server. The results can be viewed as bar charts within Iometer or exported to other applications.

Iometer can be downloaded from the Iometer website.