When Distributed FileManager/MVS detects a problem with a resource (for example, data set, storage, file lock), an attempt is made to free the resource or wait for the resource to become available (waiting does not occur with all resources). A "command check" (CMDCHKRM) reply message is returned to the source system after Distributed FileManager/MVS detects a resource problem. Command check usually indicates a problem with the software or hardware. This problem requires diagnosis. Command check is not limited to an inability to free a resource. In most cases, the resource could not be obtained because of a logic error— not because it is temporarily unavailable. If the resource is unavailable after a period of time, the "resource limits reached" (RSCLMTRM) reply message is returned to the source system. See Table 1, Table 2, and Table 3 for more information about RSCLMTRM reply messages.