Thinking Technology

Directory Services and AD System Files

I realized on Saturday that I hadn’t blogged on Friday as planned. But at least I remembered! I wanted to continue with my answering of AD interview questions. So I started researching:

“Can you connect Active Directory to other 3rd-party Directory Services? Name a few options.”

And apparently not the only person out and about answering these questions.

I landed on & was a VERY interesting site. This site was a place for people to post various interview questions and to have people reply with answers.

Back to the question: “Can you connect Active Directory to other 3rd-party Directory Services? Name a few options.”

The short answer is yes, Active Directory uses LDAP (see previous post)

Pasted from

eDirectory: This is Novell’s implementation of directory services. It supports multiple architectures including Windows, NetWare, Linux and several flavours of Unix and has long been used for user administration, configuration management, and software management. eDirectory has evolved into a central component in a broader range of Identity management products. It was previously known as Novell Directory Services.

Red Hat Directory Server: Red Hat released a directory service, that it acquired from AOL’s Netscape Security Solutions unit,[1] as a commercial product running on top of Red Hat Enterprise Linux called Red Hat Directory Server and as part of Fedora Core called 389 Directory Server.

Open Directory: Apple’s Mac OS X Server uses a directory service named Open Directory, which implements LDAP using a customized build of OpenLDAP and integrates support for both SASL and Kerberos authentication. It uses a plugins architecture to work with other LDAPv3 directories, including proprietary solutions like Active Directory and eDirectory.

The how or why of this question was much harder to come by. I’d guess if you have a previous Directory Service implementation running and wanted to migrate to Active Directrory (or vice versa).

Where is the AD database held? What other folders are related to AD?

The files that make up Active Directory are:

  • NTDS.dit – this is the database file that contains the AD Data
  • Edb.chk – Called the checkpoint file, this file tracks what transactions from the log file have been recorded/committed to the database.
  • tmp.edb – temporary data file, temp space for processing transactions
  • edb.log – primary log file, contains all transactions that haven’t been comitted to the NTDS.dit
  • Edb00001.log & Edb00002.log – secondary log files.

The default location of the files: %SystemRoot%\NTDS folder


Windows Server 2008 Inside Out [Paperback]
Paperback: 1520 pages
Publisher: Microsoft Press (April 6, 2008)
Language: English
ISBN-10: 9780735624382
ISBN-13: 978-0735624382
ASIN: 0735624380
Product Dimensions: 9 x 7.5 x 2.6 inches

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