The Design and Implementation of AQuA: An Adaptive Quality of Service Aware Object-Based Storage Device

As storage systems are becoming larger and more complicated, they must handle an increasing variety of data storage needs. Storage system Quality of Service (QoS) has therefore become an important issue. Storage systems must be able to deliver satisfactory performance under both expected and unexpected workloads and, increasingly, must handle data (such as multimedia data) with real timeliness requirements. We are developing a petascale high-performance distributed object-based storage system called Ceph. Ceph’s object storage architecture and other unique features have given rise to new QoS issues that require new solutions. In this paper, we first discuss the issues involved with the design of the overall QoS framework, we then present the design and implementation of AQuA, an adaptive QoS-aware object-based storage device (OSD) suitable for use as the fundamental building block in an overall QoS-capable object-based storage system. 1