Other system data set failures

You should make periodic backup copies of IMS system data sets so that if an error occurs, you can recover your data or recreate it from a backed up copy.

If an error occurs on an IMS data set, such as IMS.ACBLIBx or IMS.FORMATx, you need to recover it. If you have made periodic backup copies of the data set, you can use the latest copy. If you have not changed the content of the data set since making the copy, you can use it as is. If you have changed the content of the data set since making the copy, for example, you have added ACB generations since copying the ACBLIB data set, you need to redo the changes before the backup copy can be considered up-to-date.

If you have not made backup copies of the data set, you need to recreate it. For example, if you lose the active format library (IMS.FORMATx) and you have no backup copy of it, you need to rerun Message Format Services and redo all your format definitions.

If you have inactive data sets from an online change, you can recover those data sets involved with online change (MODBLKS, ACBLIB, and FORMAT). In this case, you must reapply any changes made to the system data sets.

IMS does not offer any specific utilities or commands to recover system data sets.