The Active Directory data store contains information that aided is distributed to all domain controllers
throughout the forest infrastructure.
Much of the information that the data store contains is distributed within a single domain.
However some information may relate to or replicate throughout the entire forest regardless of the domain
boundaries to help provide replication efficiency and scalability between domain controllers.
The Active Directory data is separated logically into several partitions each partition is a unit of
replication and each partition has its own replication topology.
The default partitions include the following configuration partition schema partition the main partition
and application partition.
Let's take a closer look at each of these partitions configuration partition the configuration partition
is created automatically when you create the first domain controller in a forest the configuration partition
contains information about the forest wide a tedious structure including which domains and sites exist
and which domain controllers exist in each domain.
The configuration partition also stores information about forest wide services such as Dynamic Host
Configuration Protocol authorisation and certificate templates.
This partition replicates to all domain controllers in the forest.
It is smaller than the other partitions and its objects do not change frequently.
Therefore replication is also infrequent.
Next stop is schema partition.
The schema partition contains definitions of all the objects and attributes that you can create in the
data store and the rules for creating and manipulating them schema information replicates to all domain
controllers in the forest.
Therefore all objects must comply with the schema object and attribute definition rules ADT s contains
a default set of classes and attributes that you cannot modify.
However if you have schema admins or group credentials you can extend the schema by adding new attributes
and classes to represent application specific classes.
Many applications such as Microsoft Exchange Server and Microsoft System Center Configuration Manager
may extend the schema to provide application specific configuration enhancements.
These changes target the domain controller that contains the forest schema master role only the schema
master can make additions to classes and attributes similar to the configuration partition the schema
partition is small and needs to replicate only when changes a cure to the data that is stored there.
This does not happen frequently except in those cases when the schema is extended.
Next up is domain partition.
When you create a new domain aid it is automatically creates and replicates an instance of the domain
partition to all of the domains domain controllers the domain partition contains information about all
domain specific objects including a user's groups computers organizational units and domain related
system settings.
This usually the largest of the eight it is partitions because it stores all the objects that the domain
contains.
Changes to this partition is fairly constant because every time an object is created deleted or modified
by change changing and attributes well you those changes must then be replicated.
All objects in every domain partition in a forest are stored in the global catalogue with only a subset
of their attribute values.
And finally application partition the application partition stores non domain application related information
that might tend to be updated frequently or have a specified lifetime such as the domain name system
partition when Active Directory integrated DNS is enabled an application typically is programmed to
determine how its doors categorizes and user's application specific information that is stored in the
Active Directory database to prevent unnecessary replication of an application partition.
You can designate which domain controller is in a forest will host the specified applications partition
unlike a domain partition and application partition does not store security principal objects such as
user accounts.
Additionally the global catalog does not store data that is contained in application partitions.
The application partition size and replication frequency can vary widely according to usage.
Use an Active Directory integrated DNS with a large and robust DNS zone of many domain controller Soros
and client computers will result in the frequent replication of the partition and a small tip for you.
You can use the Active Directory Services interfaces Ed or Ada DSA added to connect to the partitions
and to view them.