A file system is disclosed that includes an application wide name space instantiated in a global index (Gindex) that is used for accessing objects related to an application. Summary workload statistics are monitored and calculated via a calibrated hierarchical service level agreement (SLA) in a method of operation that includes: establishing a tenant wide name space used for accessing objects of an application stored in physical file systems across one or more appliances, each defining a storage cluster, in association with a tenant logically spanning across the appliances; and monitoring a performance statistic for the application across the tenant.