Your thought process on setting up another Secondary Copy and do Aux Copy is correct.
So this will be how I would do it:
- Setup new Environment with new MA, Disk Library and retaining old Tape Library
- Create a new Copy within the Storage Policy
- Disable the old Secondary Copy
- For new Secondary Copy, set the Source Copy to point to the old Secondary Copy.
- Trigger the Aux Copy:
- By doing the above we will be sourcing the data from the old Secondary Copy to the New Secondary Copy, and eventually as everything catches up, you can then remove the Source Copy association, so it will be grabbing from the Primary Copy again.
Assuming Deduplication is used for the old Secondary Copy, once everything is migrated to the new DR site, you will then need to Seal the DDB associated to the old Secondary Copy, either wait for the retention to be met and let jobs age, or you can manually delete all the jobs from the Secondary Copy (decommission one).
Once the Jobs are deleted, you will then need to run Data Aging and allow the Data to be physically pruned from the old Disk Library.
You will then get to a stage where the Disk Library will be disassociated to the DDB, the Sealed DDB will disappear as you have removed all the baselines, you can then remove the Disk Library, Deconfigure the MediaAgent and remove it gracefully.
The above will be the most effective way in removing/decomm a MA from CommVault (but at the same time ensuring all data is successfully replicated to the new site).
Note - you can even run Data Verification on the new Secondary Copy after Aux Copy, to ensure all data is copied successfully.
Hopefully that helps