Abstract: Data objects are stored on storage devices, taking into account service level agreements or other quality of service parameters. In one aspect, data objects grouped into storage volumes. In addition, the storage devices are classified into different level storage tiers, where higher level storage tiers have higher performance and lower level storage tiers have lower performance. Ranks for the data objects are calculated, based on both a data usage pattern for the data object (e.g., recency and frequency) and on quality of service (QOS) parameters for the storage volume containing the data object. Examples of QOS parameters include service level agreements, priority, minimum and maximum input/output operations per second. The data objects are then stored on storage devices, based on the data objects' ranks and the storage devices' storage tiers.

Abstract: An input/output (I/O) request is dispatched. A determination is made regarding a storage volume to service. A determination is made regarding whether an actual disk throughput exceeds a first threshold rate. The first threshold rate exceeds a reserved disk throughput. Responsive to determining that the actual disk throughput exceeds the first threshold rate, a first storage volume is selected based on credits or based on priority. Responsive to determining that the actual disk throughput does not exceed the first threshold rate, a second storage volume is selected based on guaranteed minimum I/O rate. An I/O request queue associated with the determined storage volume is determined. An I/O request is retrieved from the determined I/O request queue. The retrieved I/O request is sent to a persistence layer that includes the selected storage volume.

Abstract: Data objects are stored on storage devices, taking into account service level agreements or other quality of service parameters. In one aspect, data objects grouped into storage volumes. In addition, the storage devices are classified into different level storage tiers, where higher level storage tiers have higher performance and lower level storage tiers have lower performance. Ranks for the data objects are calculated, based on both a data usage pattern for the data object (e.g., recency and frequency) and on quality of service (QOS) parameters for the storage volume containing the data object. Examples of QOS parameters include service level agreements, priority, minimum and maximum input/output operations per second. The data objects are then stored on storage devices, based on the data objects' ranks and the storage devices' storage tiers.