Flexible Monitoring of Storage I/O

Abstract

For any computer system, monitoring its performance is vital to understanding and fixing problems and performance bottlenecks. In this work we present the architecture and implementation of a system for monitoring storage devices that serve virtual machines. In contrast to existing approaches, our system is more flexible because it employs a query language that can capture both specific and detailed information on I/O transfers. Therefore our monitoring solution provides the user with enough statistics to enable him or her to find and solve problems, but not overwhelm them with too much information. Our system monitors I/O activity in virtual machines and supports basic distributed query processing. Experiments show the performance overhead of the prototype implementation to be acceptable in many realistic settings.