JSI Tip 3502. The size of the Active Directory database differs on various domain controllers?

It is not unusual for the Active Directory database, Ntds.dit, to be sized differently on different domain controllers. When replication occurs, the DATA is replicated, NOT the DATABASE.

A number of factors govern the size of the Active Directory database:

1. The sate of database fragmentation, see tip 2635 How do I defragment the Active Directory database?

2. A global catalog server contains data about every object in the forest, soits' Ntdis.dit could be much larger, specially in a multi-domain forest.

3. The NTFS file system only reports the size of a file when it is opened. If you have added many objects to the active directory, and replication has occurred, and you restarted a domain controller, it's freshly opened Ntdis.dat will be larger than its' peers. If you want accurate database size information, set the Garbage Collection data value to to 1.