Abstract: A data storage system includes multiple head nodes and data storage sleds. Volume data is replicated between a primary and one or more secondary head nodes for a volume partition and is further flushed to a set of mass storage devices of the data storage sleds. Volume metadata is maintained in a primary and one or more secondary head nodes for a volume partition and is updated in response to volume data being flushed to the data storage sleds. Also, the primary and secondary head nodes store check-points of volume metadata to the data storage sleds, wherein in response to a failure of a primary or secondary head node for a volume partition, a replacement secondary head node for the volume partition recreates a secondary replica for the volume partition based, at least in part, on a stored volume metadata checkpoint.

Abstract: An aircraft camera system is described for passenger entertainment and safety that includes several arrays of digital cameras mounted on a passenger aircraft. These arrays of digital cameras, which include a top camera array, a bottom camera array, and two side camera arrays, are connected to and controlled by a central computer system. These arrays of digital cameras are positioned to view the wings, tail section, engines, and flaps on the aircraft as well as views of the horizon and ground. The passengers can access the views gathered by these multiple cameras for entertainment on their personal liquid crystal display screens, mounted in the rear back portion of each passenger seat. The crew can access the views gathered by these multiple cameras to check on the integrity of the aircraft. Also, in an emergency, the flight crew can restrict camera access to the passengers, to prevent panic.