Storage performance is one of the most difficult challenges in virtualized environments, especially those with high-end enterprise storage systems, such as cloud, database, and on-line transaction processing (OLTP) systems that may require 300,000 IOPS or higher. In this presentation, we examine how KVM performs in three typical enterprise storage environments: a fiber-attached storage system capable of delivering gigabytes of data per second, a cloud environment with high-performance NAS backend, and a high-I/O-rate environment. We will identify performance issues found in these environments and discuss potential solutions. This presentation should interest many in the Linux kernel and KVM communities, as well as those using, or planning to use, KVM with enterprise storage systems, including database, OLTP, and cloud providrs. Familiarity with virtualization is assumed.