Recovery Manager for Active Directory Forest Edition enables the recovery of a portion of the directory or the entire directory, in the event of corruption or inadvertent modification. The granular, object-level, online restore may also be used to undelete directory objects. These powerful, security-sensitive functions of Recovery Manager for Active Directory Forest Edition should only be performed by highly trusted directory administrators.
Figure 2: Recovering Active Directory
If certain objects are inadvertently deleted or modified in Active Directory, they can be restored from a backup of a domain controller’s System State, without restarting the domain controller or affecting other objects. If the Active Directory database on a particular domain controller has been corrupted, the entire database can be restored from a System State backup created for that domain controller. All the restore operations are administered remotely.
Recovery Manager for Active Directory Forest Edition offers the following restore methods:
Recovery Manager for Active Directory Forest Edition enables the fast recovery of Active Directory from a disaster. The flowchart below indicates the most suitable recovery method depending on the type of disaster, which could be data corruption, database corruption or complete Active Directory corruption.
Data corruption occurs when directory objects have been inadvertently deleted or modified, and the deletion or modification has replicated to other domain controllers within the environment.
Database corruption refers to a situation in which an Active Directory failure prevents a domain controller from starting in normal mode, or a hardware problem such as hard disk corruption on a domain controller.
Also you may experience complete Active directory corruption due to the Active Directory environment has been attacked by ransomware, or all domain controllers in the forest have been physically destroyed, etc.
Recovery Manager for Active Directory Forest Edition offers the following methods for restoring Active Directory object data on a domain controller:
Granular online restore is the most advanced method, allowing you to restore individual directory objects from a backup, without restarting the target domain controller or affecting other directory objects.
Complete offline restore only allows you to restore the entire Active Directory database on a domain controller while Active Directory is offline. To take Active Directory offline, Recovery Manager for Active Directory Forest Edition restarts the domain controller in Directory Services Restore Mode (DSRM), resulting in a period of downtime. In addition, complete offline restore affects all directory objects on the target domain controller, which may result in the loss of some of the most recent updates.
All restore operations are remotely administered, so there is no need for an administrator to be physically present at the domain controller. In most cases, it will not be necessary to shut down the domain controller in order to perform the restore: it remains online and functional throughout the recovery.
To achieve near-zero downtime when recovering Active Directory, Recovery Manager for Active Directory Forest Edition provides the granular online restore method. Two options are available with this method:
The granular online restore method allows you to retrieve individual directory objects from a backup, and then restore them to a domain controller. The operation can be performed on any domain controller that can be accessed remotely. In addition, granular online restore does not require you to restart the target domain controller, nor does it affect any directory objects that are not selected for recovery.
In addition to selectively restoring individual Active Directory objects, the granular online restore method allows you to selectively restore individual attributes of objects in Active Directory, such as the User Password, Group Membership, or User Certificate attributes of a User object. The ability to restore selected attributes ensures that valuable changes, made to Active Directory objects since the time the backup was created, are not overridden. This provides the flexibility to efficiently resolve potential problems that may result from the improper modification of individual attributes of Active Directory objects.
The granular online restore should be used in situations where important object data has been inadvertently deleted or changed in Active Directory, and the changes have been propagated to other domain controllers. To recover from such an event, you can carry out a granular online restore to Active Directory using a backup that was created before the objects in question were deleted or modified.
After Recovery Manager for Active Directory Forest Edition completes a granular online restore on the target domain controller, the restored objects are replicated to the other domain controllers via the normal replication process. Given that the objects recovered by a granular online restore have a higher version number, recently deleted or modified object data is ignored during replication.
Granular online restore allows you to roll back changes made to Active Directory, and return individual directory objects and attributes to the state they were in when the backup was created. It is important to note that a granular online restore only affects the objects and attributes selected for recovery. All other objects remain unchanged in Active Directory. Furthermore, if the value of an attribute in Active Directory is identical to the value it has in the backup, the granular online restore does not attempt to change the attribute.
A granular online restore is especially useful when you need to recover some directory objects in a short period. For example, suppose a user account is accidentally deleted from Active Directory, but exists in a backup. To recover that user account, you can perform a granular online restore, selecting the user account from the backup. The selected user account is restored to Active Directory with the same properties and permissions that it had when the backup was created. No other user accounts are affected.
With Recovery Manager for Active Directory Forest Edition, you can selectively recover deleted Active Directory objects by undeleting (reanimating) them. To undelete (reanimate) an object, Recovery Manager for Active Directory Forest Edition fully relies on the functionality provided by Active Directory, therefore to use this method you need no Active Directory backups. Note that you can only undelete objects in an Active Directory forest whose functional level is higher than Windows 2000.
The result of the undelete operation performed on an object depends on whether Microsoft’s Active Directory Recycle Bin feature is enabled or disabled in your environment. Microsoft’s Active Directory Recycle Bin is a new feature that first appeared in the Windows Server 2008 R2 operating system. For more information on Microsoft’s Active Directory Recycle Bin feature, see What's New in AD DS: Active Directory Recycle Bin (http://go.microsoft.com/fwlink/?LinkId=141392).
In an Active Directory environment where Microsoft’s Active Directory Recycle Bin feature is not supported or disabled, a deleted object is retained in Active Directory for a specified configurable period of time that is called tombstone lifetime. A deleted object becomes a tombstone that retains only a partial set of the object’s attributes that existed prior to deletion. During that period, you can use Recovery Manager for Active Directory Forest Edition to undelete (reanimate) the object. Performing the undelete operation on the object will only recover the object’s attributes retained in the tombstone.
When an object is deleted in a forest where Microsoft’s Active Directory Recycle Bin feature is enabled, the object goes through the following states:
While an object remains in the “deleted” state, you can use Recovery Manager for Active Directory Forest Edition to undelete (reanimate) the object with all its attributes, links, and group memberships that existed immediately before the moment of deletion.
Alternatively, you can authoritatively restore the object to its backed-up state from a backup created with Recovery Manager for Active Directory Forest Edition.
If necessary, you can use Recovery Manager for Active Directory Forest Edition to override the applicable deleted object lifetime setting and manually change a deleted object’s state from “deleted” to “recycled” by using a cmdlet provided by the Recovery Manager for Active Directory Forest Edition Management Shell.
To manage recycled objects, you can use the Deleted Objects container provided by Recovery Manager for Active Directory Forest Edition. In this container, you can view a list of all recycled objects in the domain, selectively recycle deleted objects, and recover recycled objects from backups created with Recovery Manager for Active Directory Forest Edition.
You can use complete offline restore to restore the entire Active Directory database from backup media without reinstalling the operating system or reconfiguring the domain controller. The restore can be performed on any domain controller that can be accessed remotely. By default, this operation restores all directory objects on the target domain controller non-authoritatively. This means that the restored data is then updated via normal replication. A non-authoritative restore is typically used to restore a domain controller that has completely failed due to hardware or software problems.
A complete offline restore also allows you to mark individual objects for authoritative restore. However, given that the granular online restore process provides the same functionality with much less effort and overhead, it is the recommend method for restoring individual objects to Active Directory.
During the final stage of a complete offline restore, the recovered domain controller is restarted in normal operational mode. Normal replication then updates the domain controller with all changes not overridden by the authoritative restore. It is important to note that until the replication update has completed, some of the directory object data held on the recovered domain controller may be unreliable. Therefore, execution of a complete offline restore may result in additional downtime due to replication delays.
There is one other consideration to make when performing a non-authoritative restore. The restored domain controller may lose information about the directory updates that were made after it was backed up. For example, suppose that some directory objects were added or modified on the domain controller after the backup was created, but the new objects or modifications were not replicated to other domain controllers due to network problems. In this case, when the domain controller is restored, the new objects or modifications will be lost, because they were never replicated to other domain controllers, and therefore cannot be applied to the restored domain controller.
Recovery Manager for Active Directory Forest Edition enables the recovery of Group Policy data from corruption or inadvertent modification, which can be caused by either hardware failure or human error.
Figure 3: Group Policy Recovery
If specific Group Policy objects or links are inadvertently deleted or modified, they can be restored from a backup of a domain controller’s System State, without restoring the entire System State or Active Directory, restarting the domain controller, or affecting other objects.
Recovery Manager for Active Directory Forest Edition includes the following options for Group Policy recovery:
You can use any combination of these options. For example, suppose some links to a Group Policy object are accidentally deleted. If your backup contains an outdated version of the Group Policy object, you can restore only the links, without restoring the policy settings or security settings.
To eliminate downtime when recovering Group Policy, Recovery Manager for Active Directory Forest Edition provides the Group Policy Restore method. This method allows individual Group Policy objects to be restored to a selected domain controller. The operation can be performed on any domain controller that can be accessed remotely. Using this method, domain controllers do not need to be restarted, and only those objects selected for recovery are affected.
For this type of restore, it is not necessary to create any special backups; you may use any regular backup of a domain controller’s System State.
A Group Policy Restore is particularly helpful when critical Group Policy objects or links have been inadvertently deleted or changed. To recover from such situations, you may carry out a Group Policy Restore to a domain controller using a System State backup that was created before the objects in question were deleted or modified.
Group Policy Restore allows you to roll back changes made to Group Policy information, and return individual Group Policy objects to the state they were in when the backup was created. It is important to note that a Group Policy Restore only affects the object selected for recovery, and optionally, the links to that object. Any objects that are not involved in the operation remain unchanged in the domain.
Recovery Manager for Active Directory Forest Edition provides comparison reports to assist with isolating deletion or changes to Active Directory or AD LDS (ADAM), and troubleshooting the resulting problems. These reports are based on per-attribute comparisons of Active Directory, AD LDS (ADAM), or Group Policy objects selected from a backup, with their counterparts in Active Directory, AD LDS (ADAM), or another backup.
By comparing the state of the directory objects or Group Policy objects in Active Directory with those in a backup, comparison reports improve the efficiency of recovering objects, by allowing you to specify precisely which objects should be restored.
By showing the changes that would be made to Active Directory or AD LDS (ADAM) during a restore operation, comparison reports help to highlight possible side effects that could result from restoring data. If such side effects are indicated in the report, you may then reconsider whether to apply the changes to the “live” directory data.
Comparison reports may also be used to monitor changes that occurred in Active Directory or AD LDS (ADAM) since the backup was created, or within the period between two backups. Comparison reports assist with troubleshooting Active Directory, and resolving problems that may result from the deletion of critical objects in Active Directory. The reports also help you monitor changes made to Active Directory or AD LDS (ADAM) by third party applications.
The ability to compare the current state of objects in Active Directory or AD LDS (ADAM) with their state in a backup helps when troubleshooting problems that may result from the deletion or modification of a user account or an Organizational Unit, or modification of more critical objects. Comparison reports show whether critical objects were deleted or modified since a backup was made.
The deletion of critical objects such as a domain controller’s computer account or the "NTDS Settings" object is one of the most common causes of Active Directory problems.
Other critical, equally sensitive objects include all objects in the System container, such as FRS subscription objects, trusted domain objects (TDO), and DNS objects. By comparing the current state of objects in the System container with the state of the objects in a backup, it is possible to isolate problems that result from the absence or incorrect modification of critical objects.
Recovery Manager for Active Directory Forest Edition serves as a valuable tool when implementing a change management process. The importance of testing changes to Active Directory is paramount, whether you are changing configurations, installing new software, or implementing service packs and patches. The product has the ability to report changes, and if necessary, roll back changes made to Active Directory. This improves the effectiveness of testing application deployment scenarios in a laboratory environment, and monitoring changes made to Active Directory by third-party applications.