To migrate database:
https://wiki.ocsinventory-ng.org/09.Extras/Backup-restore-of-OCS-Inventory-NG-database/
To install OCS to Rocky Linux 8:
I used the following resource to install from RPM.
https://computingforgeeks.com/how-to-install-ocs-inventory-server-on-centos-8/
Might need to enable Powertools as described in here:
https://www.how2shout.com/linux/how-to-enable-powertools-repository-on-rocky-linux-8/
conexiva 