Disclosed is a system, method, and program for managing I/O operations transmitted from a computer system to a processing unit. The processing unit manages access to a storage device and executes the I/O operation against the storage device. The processing unit receives indication that a request to connect between the processing unit and the computer system failed. Upon receiving a subsequent I/O operation from the computer system after receiving indication that the connect request failed, the processing unit returns busy to the computer system initiating the subsequent I/O operation in response to receiving indication that the connect request failed. The connect request is retried after returning busy.