6 Message Handling

The SMC intercepts specific MVS, JES3, and Tape Management System (TMS) messages related to mount, dismount, and swap operations. When the intercepted message includes a drive defined to a TapePlex, the SMC directs the owning TapePlex to perform the requested operation.

Messages that are intercepted by the SMC are listed in Appendix A, "Intercepted Messages."

Note:

The IATUX71 user exit must be installed to allow JES3 mount messages to be processed. Refer to the publication Installing ELS for more information.

User Directed Message Handling

If the SMC does not currently support the Tape Management System at your installation, you can still direct the SMC to intercept the specific messages issued by your TMS. Use the USERMsg operator command to define these additional messages. Refer to the ELS Command, Control Statement, and Utility Reference for more information.

User Exit 01 enables you to change or enhance actions taken on intercepted messages, and can direct the SMC to perform actions on messages that are not in the intercepted message list.

The SMC calls the user exit for each intercepted message. This includes the default messages listed in Appendix A, "Intercepted Messages" and all messages defined using the USERMsg command.

Note:

  • Only messages intercepted by the SMC are passed to the user exit.

  • The SMC does not support the user exit 01 return code of REPLY.

Message Handling Policies

The SMC honors the following MVS and SMC policies related to mount, dismount, and swap message handling:

MVS Policies

The System Authorization Facility (SAF) enables tape protection at the volume level (CLASS=TAPEVOL) using your current security software. If defined, the SMC honors the policies defined through the SAF interface regarding the write-protect requirement for a volume mounted on a library transport. The SMC invokes the SAF interface by issuing a RACROUTE macro, and protects read-only volumes through the ACS Virtual Thumbwheel (VTW) support.

SMC Policies

The SMC MOUNTDef command enables the control of message handling (that is, mount/dismount) options previously controlled by the HSC MNTD command, HSC input parameters and LIBGEN options, and the MVS/CSC ALTER command and input parameters.

These options control the automation of pending mounts, delete disposition at dismount time, whether messages are produced when a library volume is mounted outside the library, and when mount messages are rolled off the console.

Note:

Refer to the ELS Command, Control Statement, and Utility Reference for more information about the MOUNTDef command.

Tape Management System Support

The SMC interprets Mount, Dismount, and Swap messages from the following Tape Management Systems:

  • CA-1

  • CA-DYNAM/TLMS

  • DFSMSrmm

  • AutoMedia (Zara)

  • CONTROL-T

For tape management systems that supply a subpool, the subpool is interpreted by the SMC and used as the requested subpool name, unless overridden by user exit 01 or a TAPEREQ statement. Related messages include:

  • CTS002

  • CTT101A

  • CTT104A

  • TMS002

SMC Swap Processing

The SMC automates the swap process (I/O error or operator initiated) in the same manner as HSC enhanced swap processing. This eliminates the need for operators to find a compatible ”swap-to” device when DDR has chosen an incompatible device. If the SMC cannot find a compatible swap-to device, or if all compatible devices are busy, the SMC issues a message and control is returned to DDR processing with no further SMC involvement. Enhanced swap processing is the only mode supported in SMC.

On JES3 systems, the SMC does not influence the swap-to device selection. The SMC does not issue SMC0107 or SMC0110. JES3 can select a compatible drive itself based on proper initialization deck definitions. The SMC still automates the swap when the IGF502E is received.

The SMC swap process begins when one of the following messages is issued:

IGF500I SWAP XXX1 TO XXX2 - I/O ERROR
IGF503I ERROR ON XXX1, SELECT NEW DEVICE
IGF509I SWAP XXX1 - I/O ERROR

If device XXX1 is known to the SMC as a library device, the SMC suppresses the message and begins the automatic swap process.

The SMC issues one of three messages:

  • SMC0108 No compatible drive found for SWAP processing

  • When a compatible drive can be selected by the SMC:

    SMC0107 SWAP volser from XXX1 to XXX2

  • When the MOUNTDEF SWAPLIMIT count has been exceeded:

    SMC0233 SWAPLIMIT=NNNNNN exceeded; swap processing canceled

If SMC0108 has been issued and MOUNTDEF SWAPAUTOREPLY is on then message IGF500D or IGF509D will be replied to with NO.

If SMC0233 has been issued and the bypassReply variable of MOUNTDEF SWAPLIMIT is OFF then message IGF509D will be replied to with NO.

Device XXX2 is the SMC-selected device that has been determined to be compatible for the swap. The SMC next suppresses the MVS IGF500D or IGF509D message and replaces the message with:

SMC0110 Allow swap of volser from XXX1 to XXX2;
Reply 'Y', or 'N' or DEVICE

The operator may approve the device selected, cancel the swap or choose a different device. If the operator selects a different device, the SMC accepts the device with no further compatibility checking.

If the reply is 'Y' or a new device, MVS issues the following message:

IGF502E PROCEED WITH SWAP OF XXX1 TO XXX2

If XXX1 is a library owned device, the dismount of the volume is automated. If XXX2 is a library owned device, the mount of the volume is automated.

Note:

Ensure that your MVS security package (for example, RACF, TopSecret) is configured to grant SMC the necessary authority to respond to MVS swap messages IGF500D and IGF509D.

HSC Mount-Related Messages

Certain mount-related messages may still be issued by the HSC due to error conditions.

  • SLS0088D is issued when, due to an error condition, a repeated mount for the same volume is required.

  • SLS1075D is issued when a dismounted volume encounters an I/O or other type of error.

Managing HSC Mounts from the SMC Client

SMC client/server architecture provides the ability to perform management of certain mount/dismount exception conditions from the client console rather than from the server console. Conditions handled by the SMC include the following:

  • Displaying messages on the drive and console indicating the volume and its location for manual mounts when an LSM is offline.

  • When a drive is found to be loaded with another volume during a mount request from a job in execution or JES3 setup processing, the dismount is forced and the mount is automatically redriven based on the UCB outstanding mount status (or JES3 SETUNIT).

    Note:

    When a mount or dismount message is intercepted by SMC and directed to an HSC server, the SLS0107D message is not issued on the server or client. When a loaded drive condition is detected by the HSC for an SMC directed dismount, the HSC waits one minute for the drive to unload, and then terminates the dismount. If the dismount is performed as part of a mount request from the SMC, the loaded drive status is returned to the SMC, and the SMC then redrives the mount request if the mount is still pending.

  • When a drive or volume is in use by another process, verifying that the mount is still pending, periodically retrying the request, and allowing the operator to cancel or retry the request at any time

  • When the TAPEPlex WTORdest Client option is selected, certain WTOR messages are not issued on the HSC server but are sent directly to the client console instead. The operator response to the message is then transmitted back to the server, as SMC redrives the mount or dismount to the server. The following HSC mount/dismount WTOR messages are currently supported with this option:

    • SLS0134

    • SLS0905

    • SLS2126

    • SLS2905

    • SLS2984

    • SLS0109

    • SLS4084

    Refer to the publication ELS Messages and Codes for more information about these messages.