You cannot create a new system index. Only the existing system indexes defined internally by Directory Server are maintained.
You can use DSCC to perform this task. For information, see Directory Service Control Center Interface and the DSCC online help.
Create the new index configuration.
Use the dsconf create-index command-line utility to configure the new index information by specifying the attribute that you want to index.
For example, to create an index entry for the preferredLanguage attribute, use this command:
$ dsconf create-index -h host -p port dc=example,dc=com preferredLanguage
The command dsconf create-index sets the index configuration, but does not actually create the index files necessary for searches. Generating the index files can affect performance. To give you more control over the indexing procedure, generating the index files is done manually after the new index configuration has been created.
Always use the attribute’s primary name when creating indexes. Do not use the attribute’s alias. The primary name of the attribute is the first name listed for the attribute in the schema, for example, uid for the userid attribute.
(Optional) Set the index properties by using the dsconf set-index-prop command.
The dsconf create-index command creates an index with default properties. If you want to modify these properties, use the dsconf set-index-prop command. For more information about modifying index properties, see To Modify Indexes.
When the configuration of an index is modified, re-indexing is required for the changes to take effect and to use the index again.
Generate the index files.
See To Generate Indexes.
Repeat the previous steps for all servers that you want to be indexed.