You can refer to the following analogy:
- CommServe is the Brains and contains all the configuration and Backup Information
- MediaAgent will be the arms and the legs. The CommServe will send request to the MediaAgent to intialize the Data Movement
- Client will be tools that the MediaAgent will interact with
In any scenario where you would like to retain the configuration of the MediaAgent you should not be removing the reference from the CommServe. Its like the Brains has severed the connection to the arms and legs.
You can however do maintenance on the MediaAgent (OS Level) and in the scenario where the OS is corrupted (due to Hardware Issues and etc), when you reinstall the OS and Commvault software you can use the same Host Name and Client Name (referenced in the CommServe DB), so once the installation is done, it will inherit all the settings (Disk Library association and Storage Policy).
In your current state you will need to re-install the MediaAgent and re-configure all the references to Disk Library and Storage Policy Data Paths.
Feel free to reach out to support if you need any guidance