Data storage system with table-driven device selector

Abstract

In response to a storage access request, eligible data storage device types are efficiently identified in a data storage library. A list of the appropriate data storage device types is prepared by indexing attributes with corresponding pre-prepared tables and then combining the resultant indices. In one embodiment, the attributes may include recording technology ('RT') and media type ('MT') attributes. First, a user request is received for data access in the library. The request includes the RT and MT attributes. The RT attribute is indexed to a RT table to yield a RT mask. The MT attribute is similarly indexed to a MT table to yield a MT mask. In the RT and MT masks, storage device types may be represented by different codes to preference the device types with respect to each other. A request mask is prepared by performing a Boolean operation, such as AND, to combine the MT mask and the RT mask. The request mask identifies all data storage device types in the library compatible with the received request.