Datacom MUF region gets an SVC dump for an abend in IBM IOS module IECVEXSM

Article Id: 129507
Status: Published
Updated On: 14-03-2019 09:34
Products:
CA Datacom , CA CIS , CA Common Services for z/OS , CA 90s Services , CA Database Management Solutions for DB2 for z/OS , CA Common Product Services Component , CA Common Services , CA Datacom/AD , CA ecoMeter Server Component FOC , CA Easytrieve Report Generator for Common Services , CA Infocai Maintenance , CA IPC , Unicenter CA-JCLCheck Common Component , CA Mainframe VM Product Manager , CA Chorus Software Manager , CA On Demand Portal , CA Service Desk Manager - Unified Self Service , CA PAM Client for Linux for zSeries , CA Mainframe Connector for Linux on System z , CA Graphical Management Interface , CA Web Administrator for Top Secret , CA CA- Xpertware
Issue/Introduction:

One of the following messages can be found on the Datacom Multiuser (MUF) joblog:
DUMP TITLE=COMPON=EXCP - STORAGE MANAGER ,COMPID=SC1C6,ISSUER=IECVEXSM,IECVSMFR,PROGRAM ERROR                      
or 
DUMP TITLE=COMPON=EXCP - STORAGE MANAGER ,COMPID=SC1C6,ISSUER=IECVEXSM,IECVSMFR,ABEND= C0D   
but the region doesn't crashes.    

Cause:

The problem is actually in the IBM code and it occurs when one or more applications are actively performing GETIT processing, which causes sequential read-ahead in MUF. 
 

Environment:

Datacom/DB 15.0 or higher on z/OS - applications performing GETIT processing

Resolution:

IBM APAR OA56384 (title: ABEND C0D IN IECVEXSM ABEND 0C4 IN IECVEXSM) has been opened for this problem. The related IBM PTF must be applied to solve the error.

Additional Information:

Workaroud: if the IBM PTF cannot be applied, the Read-ahead feature of Datacom sequential processing can be disabled using the console-like command:
DIAGOPTION 17,1,ON
To enable it again, the following command must be issued:
DIAGOPTION 17,1,OFF

NOTE: Disabling this feature could adversely affect the performance of the applications using sequential commands, as Read-ahead is a sort of "prefetch" that can reduce the number of I/O operations.

In order to use these console-like commands, Datacom/DB 15.0 SO05768 must be applied.