Performance Implications of Storage I/O Control–Enabled NFS Datastores in VMware vSphere 5.0
Storage I/O Control (SIOC), a feature that was introduced in vSphere 4.1, provides a fine-grained storage control mechanism which dynamically allocates portions of hosts’ I/O queues to VMs whose data is located on the same datastore. This dynamic allocation is based on shares that an administrator assigns to the VMs. Using SIOC, vSphere administrators can allocate more shares to the VM that is running a high priority application, which ensures that the application can maintain a higher level of performance during peak load periods. SIOC is enhanced in vSphere 5.0 to include support for NFS datastores. This paper shows the advantages of using SIOC when consolidating applications on a vSphere-based virtual infrastructure.