Schema is the way the LDAP directories like Red Hat Directory Server and Active Directory describe entries. The schema defines the type of entry in general through the object classes. Each object class has certain attributes, something which describes a part of the entry. For example, a person object class is for a general entry about a person. This has attributes for a person's first and last names and telephone number, all normal information to describe about a person.

An attribute entry must define the following:

# displayName
attributetype ( 2.16.840.1.113730.3.1.241
        NAME 'displayName'
        DESC 'RFC2798: preferred name to be used when displaying entries'
        EQUALITY caseIgnoreMatch
        SUBSTR caseIgnoreSubstringsMatch
        SYNTAX 1.3.6.1.4.1.1466.115.121.1.15
        SINGLE-VALUE )

An object class entry must define the following:

For example, this is the Penrose Virtual Directory schema entry for the inetorgperson object class:

# inetOrgPerson
objectclass     ( 2.16.840.1.113730.3.2.2
    NAME 'inetOrgPerson'
    DESC 'RFC2798: Internet Organizational Person'
    SUP organizationalPerson
    STRUCTURAL
        MAY (
                audio $ businessCategory $ carLicense $ departmentNumber $
                displayName $ employeeNumber $ employeeType $ givenName $
                homePhone $ homePostalAddress $ initials $ jpegPhoto $
                labeledURI $ mail $ manager $ mobile $ o $ pager $
                photo $ roomNumber $ secretary $ uid $ userCertificate $
                x500uniqueIdentifier $ preferredLanguage $
                userSMIMECertificate $ userPKCS12 )
        )

Schema files can be created through Penrose Studio. The new schema is then processed through Penrose Studio and sent to the Penrose Server, which writes it to a new file in the server configuration.

To create custom schema in Penrose Studio:

Importing a schema file uses Penrose Studio to load an existing schema file into Penrose Server. As with creating a new schema file, the local file is imported into the Penrose Studio configuration, serialized to Penrose Server, and written into the server configuration.

Any schema file can be loaded into Penrose Server to be available for the virtual directory entries. For Penrose Server to recognize the schema file, it must have a .schema extension.

To load the schema into Penrose Server manually:

Penrose Virtual Directory uses OpenDS-style schema files for some internal operations and OpenLDAP-style schema files for others. Penrose Virtual Directory has a tool, schema.sh, which can convert the OpenLDAP schema files to OpenDS schema files so that they can be loaded into Penrose Server.

Any custom schema file used with Penrose Virtual Directory has to be loaded into its OpenDS service as well as Penrose Server.