Reinstall due to lost license key

have client that performed the All-in-one installer on a RHEL system and the license.pvk file is no longer on the system and there is not a backup.

Are there re-installation procedures?
The client is interested in reinstalling modularly now vs. the all-in-one install and re-install db2, BigFix and ILMT on a new system. But they do not want to loose their current data within DB2. - Can they just re-install the product components and backup/restore the databases on the new server?

Suggest you will need to work with Support on this. My understanding is that if they don’t have the .pvk they will need to create a new one for any reinstall, upgrade, or maintenance. I don’t think you can bring over the existing deployment, they’ll need to reinstall the clients and relays with a new masthead.

That is correct. If you lose the private key you have lost the control over the deployment. Definitely contact support.