Topics | How To | Full System Restore | Related Topics
Full iDataAgent Restore Considerations
What is Restored
Restoring Domain Controllers
Specific Boot Modes
A full iDataAgent restore is the process of fully restoring a client's File System and system state. Full iDataAgent restores can be helpful or even necessary, depending on circumstances. For example, full iDataAgent restores can be used to:
The distinction between a full iDataAgent restore and other restore types lies in the type of data you are restoring. A full iDataAgent restore recovers not only regular data files and directories to their original paths, but recovers the system state as well (if required). The File System and system state can be restored at the same time without an intervening restart. By default during full iDataAgent restores of File System data, the system restores all data by unconditionally overwriting the corresponding files of the system being established.
The restore process is performed at the backup set level. If the client computer has two or more backup sets, be prepared to identify the backup set whose data you want restored during the restore process. (In general, all backup sets of a given client computer encompass the entire file system; however, backup filters, which can be unique, can introduce differences.)
Restoring a computer may require re-installing the operating system. In addition, the procedure for restoring a domain controller differs from that for restoring a non-domain controller. See Restoring Domain Controllers for information on restoring a Domain Controller.
The flowchart illustrates the workflow for restoring a File System client computer.
In order to ensure the Registry is properly restored, note the following scenarios when restoring a Windows File System client with QSnap installed:
As part of the full iDataAgent restore, you can restore any or all of the following:
Full iDataAgent restore always restores file system data in place. If the original path is not present, the file restore will fail. All files are restored to their original paths; however, if any files are locked at the time of restore, the system automatically writes each locked file to another file name within the same directory and records the instance in the Windows registry.
For information on backing up and restoring the Windows File System system state, refer to the System State page.
For information on full system restore of the Office Communications Server, refer to the Office Communications Server - Full System Restore page.
By default, the system files and registry entries are excluded from the restore. However, in the following situations you may want to restore these files and registry entities:
You can do this by creating the nDisableGalaxyMerge registry key and setting the appropriate value.
Domain controllers are Windows 2000 and Server 2003 clients that have replicas of the Active Directory ó the directory service for Windows 2000 and Server 2003 servers. The Active Directory provides a single point of administration; it contains information on objects and provides users access to resources.
Active Directory servers can also be backed up with the Active Directory iDataAgent.
A domain controller also has the System Volume (SYSVOL) system state object. SYSVOL is a shared directory that stores the server copy of many of the domainís public files. The SYSVOL share is replicated across all domain controllers in the domain using the Window's File Replication Service (FRS). FRS replication of the SYSVOL occurs daily, on the same schedule as the Active Directory replication.
Domain controllers communicate with each other across the network, replicating data and network information. This replication takes place automatically, according to the schedule you established during Windows installation. When restoring the system state to a domain controller, you can decide how to replicate restored data across the domain.
The steps for restoring a domain controller depend on the desired restore type: authoritative, non-authoritative, or primary. The following chart lists the three restore types for the Active Directory, cluster databases, and SYSVOL. Explanations follow.
|System State Object||Non-Authoritative||Authoritative||Primary|
|Active Directory||Default||Use ntdsutil after the non-authoritative restore to make the restore authoritative||Not applicable|
|Cluster Databases||Not applicable||Use the authoritative restore utility to complete the restore||Not applicable|
The system performs a non-authoritative restore of the Active Directory by default, ensuring that any Active Directory data that has changed since the last backup is not replicated to other domain controllers. After a non-authoritative restore, Active Directory replication ensures that the restored domain controller receives a current replica of the Active Directory. During this process, any new objects that have been created since the backup are replicated to the restored domain controller.
If desired, you can force an authoritative restore of the Active Directory, replicating all the restored data to the remainder of the domain controllers in the domain. To force an authoritative restore, run the NTDS utility (ntdsutil) after running a full iDataAgent restore.
The Active Directory uses a Tombstone mechanism to delete objects from its directory on Windows 2000 and Server 2003 clients. When an Active Directory object is deleted from a domain controller, it is initially marked as tombstoned and is not fully removed from the directory. During Active Directory replication, the tombstone attribute is replicated to the other domain controllers, temporarily deleting the object from all the domain controllers. Once the tombstone lifetime is reached, the object is permanently removed from the directory. The Active Directory Tombstone has a default lifetime setting of 60 days.
When performing restore operations, you must consider the Active Directory tombstone lifetime. Restoring from a backup that was secured more than a lifetime before the restore may result in Active Directory inconsistencies. The restored domain controller may have objects that are not replicated on the other domain controllers. These objects will not be deleted automatically, as the corresponding tombstones on the other servers have already been deleted. Therefore, when you restore from a backup that is older than the tombstone lifetime, you may have to manually delete each unreplicated object on the restored computer in order to resolve inconsistencies.
Restores of the Cluster Databases are always authoritative. The system state restore will place the restored cluster data in a temporary location. The backup administrator may then use the Authoritative restore utility (authorutil) to restore the data if desired.
|When the Active Directory or SYSVOL is restored to a domain controller, by default it is restored in a non-authoritative mode. After restoring in the non-authoritative mode, newer data on the network is propagated to the restored computer, updating it with any newer information. A non-authoritative restore is illustrated in the following diagram.|
When the restored data is meant to override the data on other domain controllers,
it should be restored using the authoritative mode. Once this data is restored
to the domain controller, it is propagated to the other domain controllers
and overwrites any newer data on those computers. The authoritative mode
is used if critical SYSVOL or Active Directory system state objects have
been deleted and the deletion has been propagated throughout the domain.
An authoritative restore is illustrated in the diagram below.
A primary restore, which is performed for a standalone domain controller or the first domain controller in the network, marks the restored data as the primary data for all replicas within the domain. This creates a new File Replication Service (FRS) database and pushes the replicated SYSVOL data to any domain controllers added to the replication system.
|A primary restore should be used only when all other domain controllers are non-functional and you want to rebuild the domain from the last backup. Do not perform a primary restore if any other working domain controller from this domain is available.|
When restoring the SYSVOL and Active Directory on a domain controller, the computer must be restarted in the Directory Services Restore mode. For Windows 2000 clients, restart the computer and press F8 upon system startup, then select the Directory Services Restore Mode. For Windows Server 2003 clients, see the documentation accompanying the Windows Server 2003 operating system for instructions on starting in Directory Services Restore mode.
You may also restore file system data on a domain controller that is in the Directory Services Restore mode. The restore process will restore the File System data and system state data in one restore operation. When complete, the computer must be restarted into the normal mode of operation.
|If the computer is not a domain controller, it is not necessary to restart it in the Directory Services Restore mode, as there is no Active Directory present. You can fully restore all components with one operation.|
When using these options you must store or change the job results to a local drive. (For step-by-step instructions, see Change the Job Results Path of a Client.)
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