Accessor control failover in an automated data storage library

摘要

A method, system and a computer program product to increase the availability of an automated data storage library for accessing and storing data storage media are provided. Work requests received by an accessor controller of the library from a host computer are also received and stored by a work request tracking controller. The accessor controller converts the work request into commands necessary to direct an accessor to fulfill the work request, and then sends such commands to an accessor. Upon detection by the work request tracking controller that the so-directed accessor failed to conduct the command issued by the accessor controller, the work request tracking controller reconstructs the work request and sends it to an accessor controller. The provision of a work request tracking controller is a failover mechanism in the event an accessor controller fails to successfully direct an accessor to conduct commands in furtherance of a work request and/or has, for whatever reason, lost the work requests in its queue.