KVM IO profiling

This paper focuses on the evaluation of KVM options related to Input/Output performance. The technology developed by Red Hat offers many choices to the end user for configuring the interaction between the Virtual Machine and the real storage space. This document presents tests and recommendations in a bottom-up approach, starting with the virtual drive interface emulated by hypervisor and covering details up to the way that host´s file system acts while flushing guest´s data to the disk drive. In this paper we analyze many options provided by KVM, evaluate the performances delivered and extract some relevant “best-practices” conclusions.