Window-Based Prority Tagging Of Iops In A Distributed Storage System

A distributed storage schemes manages implementation of QoS targets for IOPs across compute nodes executing applications, primary storage nodes storing a primary copy of a logical storage volume, and clone storage nodes. On the compute node, a maximum priority is assigned to a minimum number of IOPs in a queue within a time window from a time of receipt of a last unexecuted IOP. Other IOPs are assigned a minimum priority. On the storage node, maximum priority IOPs are assigned to high priority queues, from which IOPs are executed first, and low priority IOPs are assigned to low priority queues. Methods for determining the capacity of storage nodes and allocating storage requests are also disclosed.