Extend function requirements
Control region requirement (IMS Control Region)
When performing an online extend, you must define the database to the IMS Control Region with ACCESS=UP.
DEDB maintenance requirements
The following maintenance requirements apply to the online Extend function when you increase the size of IOVF or SDEP storage portions of a DEDB:
After extending IOVF, you must update the DBD and the ACB with the increased ROOT size because the ACB is not updated with the increased ROOT parameter when the extend for IOVF has been committed. However, the in-core DMAC is updated with the increased ROOT parameter.
If the ACB is not updated and the area is ever recovered, reloaded, or reinitialized to a smaller-sized IOVF, IMS will not bring the area data set online.
After extending IOVF OR SDEP, you might need to change your area data set VSAM cluster definition to allow for the extended size of the IOVF or SDEP portion the next time that you perform maintenance on the DEDB.