The IDMS CV startup can fail with error message DC390003 INSUFFICIENT REGION SIZE, STARTUP ABORTED and abend code U3994. Depending on what stage of the startup the error occurs, you may instead get error message DC390001 INSUFFICIENT REGION DETECTED AT STARTUP. This can happen after upgrading IDMS to a new release or after making SYSGEN changes.
The problem is caused by IDMS being unable to obtain enough storage. It is is most likely due to insufficient storage below the line but it could also be due to insufficient XA storage.
To resolve the problem check the following:
Release: IDADSO00100-18.5-ADS-for CA-IDMS