Making an image copy of a shared database

Because the Online Database Image Copy utility (DFSUICP0) always requests read access, it can share the database only with IMS systems that request a read-only access. If the other IMS systems need to update the database while you take an image copy, use the Concurrent Image Copy option.

Given the following initial and target configurations, use this scenario to make an image copy in a database-level sharing environment:

  • Initial configuration
    • dbx is registered for database-level sharing.
    • dbx is authorized for update access to an online IMS system (IMSA).
    • dbx is authorized for read-only access to a batch IMS system (IMSB).
  • Target configuration
    • The Online Database Image Copy utility (DFSUICP0) on IMSA is authorized for read access.
    • dbx is authorized for read access to IMSA.
    • dbx is authorized for read-only access to IMSB.

Follow these steps to make an image copy:

Procedure

  1. Prevent all IMS systems from obtaining update access with the following command: CHANGE.DB DBD(dbx) READON

    This command indicates (in the RECON data set) that the database cannot be accessed by IMS systems with update intent.

  2. Suspend IMSA update activity on dbx and lower authorization to read access with one of the following commands:
    • /DBDUMP DB dbx NOFEOV
    • UPDATE DB STOP(UPDATES) OPTION(FEOV)
  3. Run the Online Database Image Copy utility (DFSUICP0).
  4. Resume update activity on IMSA with one of the following commands: 
    • CHANGE.DB DBD(dbx) READOFF
/START DATABASE dbx ACCESS=UP
    • CHANGE.DB DBD(dbx) READOFF
UPDATE DB NAME(dbx) START(ACCESS) SET(ACCTYPE(UPD))

    The CHANGE.DB command with the READOFF keyword indicates (in the RECON data set) that the database can be accessed by IMS systems with update intent.