When Microsoft’s Active Directory Recycle Bin feature is enabled in the Active Directory forest, Recovery Manager for Active Directory can use the functionality provided by Microsoft’s Active Directory Recycle Bin feature to undelete the object with all its attributes and links to the state the object was in immediately before deletion. No backups required in this recovery scenario.
In other recovery scenarios, when Microsoft’s Active Directory Recycle Bin feature is disabled or not supported, Recovery Manager for Active Directory first restores all the attributes preserved in the object’s tombstone. The remaining attributes are then restored from backup. If the backed-up value of an attribute differs from the value restored from the tombstone, then the backed-up value is restored. As a result, after the recovery operation completes, the restored object has the same attribute values, group memberships, and security descriptor as it had when the backup was created.
It is possible to determine which attributes are preserved in object tombstones by analyzing the AD schema. In such attributes, the third bit in the searchFlags property is set to 1. You can therefore enumerate these attributes using a filter that contains a matching rule such as the following:
An online restore is authoritative meaning that Active Directory replication updates all domain controllers with the restored data. However, online restore includes some additional functions. This method is designed to overcome the limitations inherent in a normal authoritative restore performed using native Windows tools. These limitations are as follows:
To overcome these limitations, the online restore method includes the following capabilities:
Recovery Manager for Active Directory provides two different methods of restoring objects online. A check box in the Online Restore Wizard allows you to specify which method to use. The agentless method uses Microsoft Tombstone Reanimation interface to undelete the object and then re-applies all attributes that are not stored in the object's tombstone from the backup using ADSI calls. This method requires that the target domain controller be running Windows Server 2008 or later.
Aside from operating system support, there are some additional differences between the two methods. The agentless and agent-based methods require different permissions to run. For example, the agentless method supports delegated permissions as outlined in the User Guide. The agentless method may not restore some attributes, depending on the operating system and service pack level, namely user passwords and SIDHistory, as these attributes cannot be set using ADSI. In order to restore these attributes using the agentless method, you can configure the Active Directory schema to store these attributes in the object tombstone as described in the User Guide.
Yes, you can undelete mailbox-enabled users with the online restore function of Recovery Manager for Active Directory. When you undelete a mailbox-enabled user within the mailbox retention period, the user’s access to the mailbox is also restored.
After a user is deleted, the Exchange Server retains the user’s mailbox for a specified period, before permanently deleting the mailbox. If the mailbox retention period has expired, the mailbox access associated with the undeleted user is not recovered. Recovery Manager for Active Directory cannot restore mailboxes that have been permanently deleted.