RE: [EXTERNAL] how to migrate an openldap server to a new linux server

I did ldapsearch to export schema from source ldap server, cmd is: ldapsearch -x -LLL -H "ldap://xxx:389" -D "cn=admin,ou=AdminUsers,dc=example,dc=com" -W -b "cn=schema" -o ldif-wrap=no > source-schema.ldif

but ldapadd this ldif to target server still report: [root@phx-ldap-ol8 openldap]# ldapadd -H ldap:/// -D "cn=admin,dc=oracle,dc=com" -W -f /tmp/source-schema.ldif adding new entry "dc=example,dc=com" ldap_add: Object class violation (65) additional info: no objectClass attribute

How to get schema defined in target server??