3PAR Cinder Driver modifications to support QoS

Currently, the OpenStack HP 3PAR Fibre Channel (FC) and iSCSI Drivers do not support Quality of Service (QoS) extra specs. The QoS settings that we would like to add include;
• maximum MB/second (maxBWS)
• maximum IO/second (maxIOPS)
These new extra specs will be scoped keys, the scoping will be qos:maxBWS and qos:maxIOPS. A new key hp3par:vvs was also added to allow the admin to predefine QOS settings on a 3PAR
virtual volume set and any volume created would be added to that predefined volume set. No additional changes would be made to OpenStack outside the HP 3PAR FC and iSCSI Block Storage (cinder) drivers.

Implementation Details
This blueprint would add the maxBWS and maxIOPS as extra specs in the existing OpenStack HP 3PAR Fibre Channel and iSCSI Drivers Cinder Drivers. Both drivers call an existing 3PAR Web Server API to create a volume on the 3PAR storage array. The 3PAR storage arrays set these values on volume sets, not the actual volume. So the change would be to create a volume set with these settings and then create the volume in that volume set.
1. Max IO/S & Max MB/S are not QoS guarantees
2. These are per volume maximums which the 3PAR is guaranteed not to exceed.
3. Settings these values does not guarantee these performance rates will be achievable