Patent ID: 8312176
Filing Date: 2012-11-13
Classification: G06F,Y02E

Abstract:
1. A non-transitory computer readable medium comprising executable instructions for performing an input/output (I/O) operation initiated by an I/O operation instruction at a host computer system configured for communication with a control unit, the computer readable medium readable by a processing circuit for performing a method comprising: sending, by a channel subsystem in the host computer system, a process login (PRLI) request message to the control unit to initialize a link between the channel subsystem and the control unit, the PRLI request message including a field having a value that indicates whether the channel subsystem supports bi-directional data transfer; receiving a PRLI response message from the control unit, the PRLI response message including a field having a value that indicates whether the control unit supports bi-directional data transfer; providing an indication to a host operating system that bi-directional data transfer is supported; and based on executing the I/O operation instruction received from the host computer system, performing a method comprising: