If a structure was in duplex-mode and a coupling facility failure or structure damage occurs to only one instance of the structure, then XES will automatically switch from duplex-mode to simplex-mode. Logger will only be notified of the mode switch change and will not be aware of any coupling facility failure or damage to the structure. See When the coupling facility structure duplex/simplex mode changes for how Logger handles mode switches for the structure.

If the structure was in simplex-mode and the failure or damage occurs to the only instance of the structure, then all systems connected to the coupling facility structure detect the failure. The first system whose system logger component detects the failure initiates the structure rebuild process. The structure rebuild process results in the recovery of one or more of the affected coupling facility structure's log streams. All the systems in the sysplex that are connected to the list structure participate in the process of rebuilding the log streams in a new coupling facility list structure.