Understanding eDirectory 8.6

Test Objective Covered:

1. Describe the function and features of eDirectory 8.6.

eDirectory 8.6 is a highly scalable, high-performing, secure directory service. Along with replication and partitioning capabilities, eDirectory provides the basic foundation for multiplatform networking. eDirectory also includes cryptography services to protect confidential data; it natively supports LDAP 3 over SSL (Secure Socket Layer).

Earlier versions of eDirectory were called Novell Directory Services (NDS). At first glance, eDirectory appears to have the same underlying architecture as NDS. That is, a distributed, object-oriented database organized as a hierarchical tree. Upon closer inspection, however, you'll find that eDirectory 8.6 is built on a much more sophisticated database structure than NDS.

Let's take a closer look at the underlying architectural differences between NDS and eDirectory, starting with NDS.

NDS Architecture

NDS was first introduced in NetWare 4. Prior to NetWare 4, NetWare operating systems relied on a server-centric model in which each NetWare server had its own flat-file database for tracking network resources (called the bindery). The bindery consisted of three files: one that held object, one that held property, and one that held value information.

NDS offered a gigantic leap forward by evolving the server-centric model into a network-centric model. In this architecture (shown in Figure 3.1), the NetWare 4 operating system relies on four data files and multiple streams files located in a hidden directory on the server's SYS: volume. This database is referred to as the RECMAN database.

Figure 3.1. NDS architecture.

The four files that make up the NDS architecture in Figure 3.1 perform these functions:

• PARTITIO.NDS The partition database contains a list of database partitions including system, schema, external reference, and bindery.

• ENTRY.NDS The object database contains records for each object in a given server's replicas.

• VALUE.NDS The attribute database contains property values for each object in ENTRY.NDS.

• BLOCK.NDS The block database contains overflow data for the attribute database.

NDS streams files are named with hexadecimal characters (0-9, A-F) and hold information such as print job configurations and login scripts. Earlier versions of NDS used Novell's Transactional Tracking System (TTS) to ensure that database transactions were either completed or backed out in the event of a system failure.

TIP

The NetWare 5 version of NDS uses the same architecture as described above; however, the names of the files are different. In NetWare 5, ENTRY.NDS is called 0.DSD, VALUE.NDS is called 1.DSD, BLOCK.NDS is called 2.DSD, and PARTITIO.NDS is called 3.DSD.

eDirectory 8.6 Architecture

eDirectory 8.6 improves on NDS' fixed-length record data store model by introducing a highly scalable indexed database called FLAIM (FLexible and Adaptable Information Manager). The FLAIM database uses three different types of files instead of four, but still relies on streams files for print job configurations and login scripts. Check out the eDirectory 8.6 architecture in Figure 3.2.

Figure 3.2. eDirectory 8.6 architecture.

Following is a description of each of the three different types of files that make up eDirectory's FLAIM database:

• NDS.DB The control file is the centerpiece of the eDirectory architecture. This file contains the rollback log and is used to abort incomplete transactions.

• NDS.01 The primary database file contains all records and indexes found on a given server. When this data file reaches 2GB in size, NDS.02 is created for the remaining data. New files are then created as necessary to keep database files from growing beyond 2GB. This allows the database files to remain scalable while retaining their quick-search capabilities.

• NDS*.LOG The transaction log file acts as a roll-forward log to reapply completed transactions that might not have been fully written to disk because of a system interruption.

eDirectory streams files perform the same function as they do in NDS and have an .NDS extension. However, unlike NDS, eDirectory does not use TTS; instead, it uses log files to back out and roll forward transactions in the event of a system failure. Refer to Table 3.1 for a summary of the differences between NDS and eDirectory architecture.

TIP

The primary eDirectory database file, NDS.01, includes a number of indexes to enhance performance. First, it includes attribute substring indexes for the "CN" and "uniqueID" fields. Second, it includes attribute indexes for the "Object Class" and "dc" fields. Finally, it includes attribute indexes for positioning that include strings beginning with CN, uniqueID, Given Name, and Surname.

Table 3.1. Comparing NDS and eDirectory Architecture

COMPONENT	NDS	EDIRECTORY
Database Name	RECMAN	FLAIM
Database Function	Fixed-Length Record Data Store	Highly Scalable Indexed Database
NetWare Version	4.x and 5.x	6.0
Number of Files	4	3
Data Records File	ENTRY.NDS	NDS.01
Roll-Back Mechanism	TTS	Log Files
Streams	Yes	Yes

The eDirectory architecture described here provides an exceptional foundation for all of eDirectory 8.6's new features and benefits. Following is a brief list of some of eDirectory's greatest new advancements:

• eDirectory 8.6 can be implemented on any of these operating system platforms: NetWare, Windows NT, Windows 2000, Linux, Solaris, and Tru64 UNIX. Client libraries and LDAP tools are available for Linux, Solaris, and Tru64 UNIX. LDAP support provides an open structure for integration with applications that are written to the LDAP standard.

• The Index Manager tool enables you to manage database indexes easily. The Filtered Replica Configuration Wizard enables you to easily create filtered replicas.

• The eDirectory Import/Export Wizard enables you to import or export LDIF files and to perform a server-to-server data migration.

• eDirectory includes a merge utility that enables you to merge one directory tree into another or to graft one tree onto another.

• iMonitor provides monitoring and diagnostic capabilities for all servers in your eDirectory tree from a web browser.

This completes our architectural lesson of eDirectory 8.6. We hope that you have gained an appreciation for the sophisticated directory services platform that eDirectory 8.6 provides for your NetWare 6 network. Now that you understand how it's built, you're ready to learn how to integrate it into your existing network.