Bourbon is a quality of service framework designed to work with the Ceph object-based storage system. Ceph is a highly scalable distributed file system that can scale up to tens of thousands of object-based storage devices (OSDs). The Bourbon framework enables Ceph to become QoS-aware by providing the capability to isolate performance between different classes of workloads. The Bourbon framework is enabled by Q-EBOFS, a QoS-aware enhancement of the EBOFS object-based file system. QEBOFS allows individual OSDs to become QoS-aware, and by leveraging on the random element of the CRUSH data distribution algorithm employed by Ceph, it is possible for a collection of independent QoS-aware OSDs to provide class-based performance isolation at the global level. This preserves the highly scalable nature of Ceph by avoiding the introduction of any centralized components or the need to collect and propagate global state information. This paper presents the Bourbon framework by first describing Q-EBOFS, and then examines how a collection of OSDs running Q-EBOFS can work together to provide global-level QoS.