If the device on which the couple data set is experiencing an expected delay, no action may be necessary. However, the I/O which is being delayed is critical to the health of the sysplex, and the delay may cause performance problems for users of sysplex services. If the delay is not expected, device or control unit diagnostics should be examined to remove the cause of the delay. If no I/O completes to the data set within five minutes, XCF will remove the data set from use. If BOTH primary and alternate data sets are removed, that function will be unavailable to the sysplex. For Sysplex and CFRM couple data sets, the loss of both data sets will cause every system in the sysplex to load a non-restartable wait state. If a data set is removed, the SETXCF COUPLE,ACOUPLE operator command should be used to install a new alternate for that type as soon as possible.