The following is a list of the considerations for your LDAP directory:
A directory server must be installed, configured and running before you run the Directory Preparation Tool.
You must run the Directory Preparation Tool on the same machine as your directory server.
You must run the Directory Preparation Tool on every machine on which a directory server resides.
If you add an additional machine that has Directory Server installed on it (such as a replica), at a future date, run the Directory Preparation Tool against it, too.
If you have customized your LDAP directory, the following considerations may apply:
If you have indexed some attributes, you may have to reindex those attributes after the Directory Preparation Tool runs.
If you have added other .ldif files (schema definitions), they should not be affected, so no action should be necessary. However, back up your custom schema definition files before running the Directory Preparation Tool.
For all customizations, including the first two just listed, stop the Directory Preparation Tool after it generates the script and before it actually updates the LDAP directory. Then inspect the script to evaluate how its proposed actions will affect your LDAP directory. Take whatever actions you think necessary to protect your customizations before running the script against your directory.