AD Database Free Space Monitor. Monitors that the free disk space on the drive that contains the AD database (DIT) is below the minimum acceptable level.
If the disk drive is full, Active Directory Domain Services will not function correctly and will cause failures for the services that use it.
Possible causes include the following:
The database size has grown through normal use of the directory.
Other files have been placed on this drive recently.
Relocate unnecessary files to an alternate volume or extend or replace the volume involved.
Perform an offline defrag on the AD database.
For more information, see:
Introduction to Administering the Active Directory Database
Performing offline defragmentation of the Active Directory database