The OAM processing for the file system sublevel uses other z/OS components including Language Environment (LE) and z/OS UNIX and, when errors occur, these other components may return additional error information to OAM. When the file system sublevel processing originates from OSMC functions and utilities within the OAM address space, this additional error information is provided in error messages and repeated error conditions will cause the OSMC functions and utilities to stop processing. When the file system sublevel processing originates from an application program, the OSREQ return and reason code size limit the amount of error information that can be communicated back to the application program. Because application programs may not stop processing as a result of these error indications, OAM could issue an excessive number of messages containing the additional error information. To prevent this, OAM will, by default, issue no more than ten messages containing the additional error information, regardless of the number of errors. There are some cases, however, when additional error information is available and you may want to temporarily allow additional messages to be displayed to assist in diagnosing errors related to the file system sublevel. The OSREQ return and reason codes may identify file system related conditions or LCS reason codes.
The following MVS command syntax starts the temporary diagnostic messages:
>>-+-MODIFY-+---------------------------------------------------> '-F------' >--OAM,-+-START-+-,-DIAGMSGS,OSREQFS,-+---------------+-------->< '-S-----' | .-10---. | '-LIM=-+-nnnn-+-'
- DIAGMSGS,OSREQFS
- Starts (if not currently active) the temporary display of additional diagnostic messages for file system related errors originating from an OSREQ request.
- LIM=nnnn
- LIM=nnnn specifies the approximate number of messages that OAM will issue when the display of these diagnostic messages is active. Valid values for nnnn are 1 through 9999. The default value is 10. If the display of additional diagnostic messages is currently active, the specified LIM value overrides the current value. The changed message limit will stay in effect until reset with another START,DIAGMSGS,OSREQFS command, or the messages are stopped by the STOP,DIAGMSGS,OSREQFS command, or OAM is restarted. When the specified LIM value has been reached, OAM automatically stops the display of the additional diagnostic messages.
It is recommended that the number of diagnostic messages displayed be limited to the minimum required to obtain the needed additional error information.
See z/OS DFSMSdfp Diagnosis, SC23-6863 for a description of the additional error information.