Defragmentation of the Active Directory Database

ID: Q229602

The information in this article applies to:

Microsoft Windows 2000 Server

SUMMARY

The underlying Extensible Storage engine (ESE) for the Active Directory database uses the quickest method to fill database pages, which is not always the most efficient method. Defragmentation is the process of taking this data and rearranging it in a more compact form. Windows 2000 Server supports both online defragmentation and offline defragmentation.

MORE INFORMATION

Online Defragmentation

With online defragmentation, database pages are effectively rearranged within the data file, but no space is released back into the file system. Online defragmentation is performed automatically by ESE at regular intervals following the garbage collection process.

Offline Defragmentation

Offline defragmentation cannot be performed while the computer is running as a domain controller; it must be performed with the computer running in Directory Services Repair mode, in which the computer is effectively running as a member server. In Directory Services Repair mode, an administrator can use the Ntdsutil.exe command-line tool to defragment the Ntds.dit file.

You can run Directory Services Repair mode by restarting the computer and selecting the appropriate item from the Boot menu. This menu is accessible on Intel-based computers by pressing F8 during startup.

Upon completion of the defragment operation, Ntdsutil.exe places a defragmented version of the Ntds.dit file into a separate folder. You can then move the defragmented file into the Ntds folder after archiving the original Ntds.dit file.

Other Considerations

Use offline defragmentation only when you know database contents have decreased considerably, and you need to reclaim some space for other users.

Retain the original Ntds.dit file until the domain controller has restarted successfully with the new compressed version of the file.

Online defragmentation makes space available, but does not reduce the size of the database file.

Only offline defragmentation provides you with a clear picture of the amount of space being used.

Additional query words:

Keywords : kbenv kbtool
Version : WINDOWS:2000
Platform : WINDOWS
Issue type : kbhowto