Storage vMotion of a Virtualized SQL Server Database: A Performance Study

Executive Summary This paper provides a deep look at the performance implications of the live storage migration of a VM running a large SQL Server database workload. Performance of the workload when migrating different components of the database (data, index, and log) was measured and compared against the steady state performance (when there was no migration). Experiments discussed in this paper also show the impact of I/O characteristics of the database components on the migration time of the virtual disk containing them. Based on the knowledge gained from the experiments, a few best practices are suggested for the live migration of the storage of the virtual machines (VMs) with minimal impact to the performance of applications running in them.