Date Added: Jul 2010
SANs enable storage consolidation and sharing among multiple servers and workloads hosted on them. Customers have varied nature of I/O applications in their SAN environments some of which are mission critical and require to be assigned resources on priority. Adherence to I/O performance SLOs as a QoS, for multiple, often competing, workloads that share a storage device attains great importance in these contexts. SLOs for a workload could typically be a minimum bandwidth (a lower bound), an average latency (an upper bound) or limiting the maximum bandwidth (an upper bound). Hence, there is often a need to overprovision storage resources in typical SAN environments to enable resource availability to obtain performance prioritization for mission-critical applications resulting in ineffective utilization of storage resources.