Configuration data for suffixes with multiple back ends is not migrated. If dsmig detects that a suffix has more than one backend, it does not migrate any of the configuration entries that belong to that suffix. This includes configuration entries for the mapping tree, replicas, replication agreements, LDBM instances, indexes, and encrypted attributes. Instead, all of these entries are dumped in the file new-instance-path/migration/old_distribution_conf.ldif.
The entries in the old_distribution_conf.ldif file refer to the old instance so should not be imported directly to the new instance. For more information about distribution, see Chapter 21, Directory Proxy Server Distribution, in Oracle Fusion Middleware Administration Guide for Oracle Directory Server Enterprise Edition.