Central User Administration Retention of Change Logs

Hello,

Our BASIS team will be spinning up a new box for Solution Manager and will be decommisionning the old one which was used for CUA.  Please advise on what the recommended approach is to retain the user change logs from the old central system to the new one which will be used as the new CUA system.  We will need to retain the change logs for reference.  Trusted RFC's were not used in the old setup. We have two child system(s) and need to be able to retain the change logs for them.  IdM may be in the future but not for awhile.

Thanks,

Todd