Abstract: A storage system and method of operating the storage system is described where the metadata used to access the data stored in a storage device is distributed amongst a plurality of controllers in communication with a user, with each other and with the storage device. Each controller stores at least the metadata needed to access the data relevant to the user at the time, and metadata is updated to respond to internal system activities such as device failures, snapshots, backup operations or the like. To preserve coherence of the metadata, each metadata update is communicated to the other controllers and the storage device. The update is either transmitted to the other controllers and to the storage device and each metadata location is updated, or the update is transmitted to the storage device and each of the controllers is instructed to request an update from the storage device.

Abstract: A variable control ball valve includes a valve body containing a valve body flow channel; a valve ball rotatably mounted within the valve body flow channel, the valve ball having a full volume diametric ball channel with a laterally extending ball channel extension having progressively diminishing cross-sectional area; and a mechanism for rotating the valve ball about a ball rotational axis relative to the valve body flow channel; so that when the valve ball is rotated beyond the point at which the ball channel is aligned with the valve body flow channel, the valve body flow channel aligns with progressively narrower segments of the ball channel extension and the flow rate through the valve body flow channel is progressively diminished.