Patent ID: 7685334

Claim:
A host library controller, comprising: a plurality of ports to establish a plurality of communication paths from the host library controller to a medium changer library; a processor; and a memory storing instructions operable within the processor, the instructions being executed to perform operations, the operations comprising: issuing a selected medium changer command from a medium changer command set, wherein the medium changer command set has medium changer non-move commands and medium changer move commands; selecting at least one port of the plurality of ports to communicate the issued selected medium changer command to the medium changer library depending on a command processing status of each port by: (a) determining that (i) no single port with zero queued medium changer non-move command exists; (ii) no single port with zero queued medium changer move command exists; and (iii) no single port with less than a specified number of queued medium changer move command exists; and (b) in response to the determining, selecting the at least one port of the plurality of ports to communicate the issued selected medium changer command to the medium changer library, wherein the selected at least one port has more than or equal to the specified number of queued medium changer move commands listed in an associated command queue of the selected at least one port; and increasing a command timeout period associated with a communication of the issued selected medium changer command from the host library controller to the medium changer library, in response to the selecting of the at least one port.