Load balancing of NVMe targets based on real time metrics can be obtained for NAS appliances mirroring a namespace by assigning the NAS appliances to service sets that include an active load balancing set, a monitored inactive set, and an out of service set. Storage performance metrics of the NAS appliances can be tracked by monitoring IO operations for accessing a NAS mirroring the namespace in a non-volatile memory. Based on the storage metrics, NAS appliances can be moved from one of the service sets to another. Dummy IO operations can be used to track the storage performance metrics of monitored inactive NAS appliances such that a monitored inactive NAS may be moved to the active load balancing set when certain performance constraints are met.