As of z/OS 2.4, AllowUserKeyCSA(NO) is compulsory.
Failure to configure IDMS properly for this change can result in an SB78-5C abend at CV startup.
Release: All supported releases.
IDMS must be configured to run in a non-user KEY - that is, one in the range 1 to 7. The recommendation is to use 4. To accomplish this, the following must be done.
PPT PGMNAME(RHDCOMVS),KEY(4),NOSWAP
//IDMS EXEC PGM=RHDCOMVS,REGION=0M,TIME=1440,PARM='STEP=Y'
It may also be a good idea to re-create the SVC with CVKEY=4 in #SVCOPT instead of CVKEY=*, but this is not necessary if the SVC was created with #SVCOPT parameter CVKEY=*. If the SVC has been created with an #SVCOPT with CVKEY=n where n is a number, then the SVC will check that the CV is running in that particular key, and if it isn't, the CV will abend with an SEnn abend code where nn is the number of the SVC in hexadecimal. If the SVC has been created with CVKEY=*, no such check is performed. Changing the SVC would only be necessary if it had already been created with CVKEY=n where n is a number other than the one which you specified in the PPT entry.