Storage benchmarking—much like Wi-Fi benchmarking—is a widely misunderstood black art. Admins and enthusiasts have for decades been tempted to just “get the big number” by reading or writing a large amount of data to a disk, getting a figure in MB/sec, and calling it a day. Unfortunately, the actual workload of a typical disk doesn’t look like that—and that “simple speed test” doesn’t reproduce a lot of the bottlenecks that slow down disk access in real-world systems.
The most realistic way to test and benchmark disks is, of course, to just use them and see what happens. Unfortunately, that’s neither very repeatable, nor is it simple to analyze. So we do want an artificial benchmarking tool—but we want one that we can use intelligently to test storage systems across realistic scenarios that model our day-to-day usage well. Fortunately, we don’t have to invent such a tool—there’s already a free and open source software tool called fio, and it’s even cross-platform!
[Source: Ars Technica]