Description:

Storage I/O Control (SIOC), a new feature offered in VMware vSphere 4.1, provides a fine-grained storage control mechanism by dynamically allocating portions of hosts™ I/O queues to VMs running on the vSphere hosts based on shares assigned to the VMs. Using SIOC, vSphere administrators can mitigate the performance loss of critical workloads during peak load periods by setting higher I/O priority (by means of disk shares) to those VMs running them. Setting I/O priorities for VMs results in better performance during periods of congestion.