Vocal Vibrations Affect on Disk Latency
Sun Engineer Brendan Gregg on the Fishworks team discovered that vocal vibrations affect disk latency through the use of Analytics from Fishworks. In a two-minute YouTube video that has garnered the attention of over a quarter of a million people, Gregg demonstrates how his vocal vibrations cause a sharp spike in the number of I/O operations per disk and a noticeable latency increase on the overall workload.
He offers a screenshot of Analytics on a Sun Storage 7410 Unified Storage System. He measures disk I/O operations broken down by latency and disk I/O operations that take at least 520 ms broken down by disk using DTrace for performance analysis of the disks. He applies a right workload to two JBODs and then proceeds to yell into them.
The effect of disk vibration is clearly evident. The screenshot shows the latency of the disks has risen and the specific disks affected demonstrate I/O operations longer than 520 ms.
“Amazing stuff,” Gregg pronounces. “This has been made possible by Analytics from Fishworks, which lets us look at things we’ve never seen before.”