Backing up your environments
Before you begin your upgrade, take a backup up your current environments. You can revert to the original environment if anything goes wrong with the upgrade, or continue to maintain your existing environments as you stage your upgrade.
About this task
On z/OS, there are multiple ways to achieve a backup:
- Run full disk backups of the SMPE and runtime environments (RTEs).
- Run DFDSS copy of the SMPE and RTEs (often referred to as 'cloning'), then install new versions into the existing environment, keeping the backup around.
- Create a cloned CSI or a cloned target zone, then install into the new cloned CSI or target
zone. If you run from target libraries, you modify your runtime procedures to run from the new
targets. To reinstate the backup, you restart your runtime process pointing to the old targets.
The following JCL symbolics in the runtime process enable you to switch between upgraded and backed up environments:
- RHILEV--the runtime high-level qualifier
- BASEHLEV--the high-level qualifier for the SMPE target libraries, a full RTE, or a base RTE