You can perform an online LDIF export using the command line or using the DSCC. For example, use the following command to export to a file called export.ldif:
$ dsconf export -p 20390 "dc=example,dc=com" /install-path/export.ldif Beginning export of 'example' example: Processed 8 entries (100%). Export finished. Task completed (slapd exit code: 0).