When starting Control Block Validity Manager, ICBM001B DSN NOT ALLOCATED

Document ID:  TEC1473916
Last Modified Date:  07/05/2017
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  • CA Database Analyzer for IMS for z/OS


  • CA Database Analyzer for IMS:DBA

When accessing Control Block Validity Manager via the ISPF Interface for CA Database Management Solutions for IMS for z/OS, error message ICBM001B occurs: 

ICBM001B: DSN=.ICB.lpar.ICBCTRL.F1 could not be allocated. Additional
diagnostic information: Return Code=12. EXEC=ICBRXDAL

This prevents the user from accessing Control Block Validity Manager.


This temporary dataset is constructed as follows with two variables:


The missing high level qualifier of 'userid' indicates that we failed to obtain the users UserID. This should be obtained from the users ISPF ZPREFIX variable. 


Issue command TSO PROFILE to check your ISPF Profile settings, specifically the PREFIX/NOPREFIX setting. The ICBM001B error suggests that NOPREFIX is set. If that is the case, issue the TSO PROFILE PREFIX command to change the setting to your userid.

This should resolve the ICBM001B error and you should now be able to access Control Block Validity Manager.

Additional Information:

On r16 and earlier releases, these temporary work datasets, were built using a high level qualifier of variable ZUSER (ISPF USERID). Some sites, however, did not allow datasets to be prefixed by a users userid. The code was therefore changed to use the TSO PROFILE PREFIX instead. Unfortunately for users at some sites, with TSO PROFILE NOPREFIX specified, this code change has meant that TSO PROFILE PREFIX has to be specified, to allow the use of PREFIX in allocating these datasets.

Subsequently PTF UO00625 on r18 has been released. Now when a user has NOPREFIX specified, then we will automatically switch to using ISPF USERID.

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