Rolling Back SYSVOL Migration to a Previous Stable State
Updated: August 19, 2009
Applies To: Windows Server 2008, Windows Server 2008 R2
If critical problems occur during the migration process before migrating to the Eliminated state, or if you determine that replication of the SYSVOL folder by DFS Replication does not meet your needs, you can roll back migration to a previous state as described in the following sections.
Notes about rolling back to a previous state
Preparing to roll back migration to a previous state
Rolling back migration to a previous state
For information about how to troubleshoot the issues before you roll back migration, see the Troubleshooting SYSVOL Migration Issues section.
Notes about rolling back to a previous state
Although you can change the global migration state back and forth as often as you want before you change it to eliminated, you should wait for the domain controllers to reach a stable state (their local states match the global migration state) before you change the global migration state again.
You can skip a stable state when you roll back migration. For example, you can roll back migration from the Redirected state to the Start state. The disadvantage to this approach is that you have no opportunity to troubleshoot problems in the intermediate stable states before you reach the state you specified.
For more information about the migration states for SYSVOL migration and the transitions between them, see SYSVOL Migration States. For information about the actions that the migration tool and the DFS Replication service perform during rollback, see SYSVOL Migration Tool Actions.
Preparing to roll back migration to a previous state
Before you roll back migration to a previous state, you should verify that the migration state is consistent for all domain controllers in the domain and that AD DS replication and SYSVOL replication are working properly.
To prepare roll back migration to a previous state
Log on to the primary domain controller (if you are not logged on already).
At a command prompt, type dfsrmig /getmigrationstate to verify that all the domain controllers are at a consistent migration state. The following output appears when all domain controllers are at a consistent migration state.
All Domain Controllers have migrated successfully to Global state (‘state’). Migration has reached a consistent state on all Domain Controllers. Succeeded.
Important
You should not roll back migration unless all the domain controllers have successfully reached a consistent migration state. You should not save the state of an individual domain controller unless that domain controller is in a stable migration state.
On each domain controller in the domain, open a command prompt window and type net share to verify that the SYSVOL shared folder is shared by each domain controller in the domain.
If you want to roll back from the Redirected state to an earlier state, this shared folder should map to the [drive:\]Windows_folder\SYSVOL_DFSR\sysvol folder that DFS Replication is replicating, and text similar to the following should appear as part of the output of the command. If you want to roll back from the Prepared state, this shared folder should map to the [drive:\]Windows_folder\SYSVOL\sysvol folder that FRS is replicating.
Share name Resource Remark -------------------------------------------------------------------------------- […] NETLOGON C:\Windows\SYSVOL_DFSR\sysvol\corp.contoso.com\SCRIPTS Logon server share SYSVOL C:\Windows\SYSVOL_DFSR\sysvol Logon server shareUse the Ultrasound tool to verify that FRS replication of the [drive:\]Windows_folder\SYSVOL folder is healthy. For information about using Ultrasound to monitor FRS replication, see the Ultrasound Help.
If you are not already using Ultrasound to monitor FRS, see the following blog post for a simpler method to check SYSVOL replication using the FRSDIAG tool https://blogs.technet.com/askds/archive/2008/05/22/verifying-file-replication-during-the-windows-server-2008-dfsr-sysvol-migration-down-and-dirty-style.aspx.
If you want to roll back from the Redirected state to the Prepared state, use the DFS Management snap-in to create a Diagnostic Report for SYSVOL_DFSR folder and confirm that the SYSVOL_DFSR folder is replicating properly. For more information, see Create a Diagnostic Report for DFS Replication.
Type repadmin /ReplSum to verify that Active Directory replication is working properly. The output should indicate no errors for all of the domain controllers in the domain.
Use the Registry Editor to verify that the value of the SysvolReady registry entry under the HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\Netlogon\Parameter subkey is still 1.
To roll back from the Redirected state to an earlier state, the value of the SysVol subkey under the same subkey should be [drive:\]Windows_folder\SYSVOL_DFSR\sysvol; to roll back from the Prepared state, the subkey should be [drive:\]Windows_folder\SYSVOL\sysvol.
To increase your recovery options in the event of a problem during the rollback process, use the Wbadmin start systemstatebackup command to back up the system state of the domain controller prior to beginning the rollback. For information about the Wbadmin command, see (https://go.microsoft.com/fwlink/?LinkId=121860).
Rolling back migration to a previous state
After you prepare to roll back migration by performing the previous procedure, you are ready to roll back migration.
To roll back migration to a previous state
Type dfsrmig /setglobalstate 1 to set the global migration state to prepared if you want to roll back from the Redirected state to the Prepared state.
or
Type dfsrmig /setglobalstate 0 to set the global migration state to start if you want to roll back from the Prepared state or Redirected state to the Start state.
Type dfsrmig /getglobalstate to verify that the global migration state is the state you set in the previous step. The following output appears for this command.
Current DFSR global state: ‘state’ Succeeded.Type dfsrmig /getmigrationstate to confirm that all the domain controllers have rolled back to the target migration state. The following output should appear when all domain controllers reach the target migration state.
All Domain Controllers have migrated successfully to Global state (‘state’). Migration has reached a consistent state on all Domain Controllers. Succeeded.This step can take some time. The time needed for all of the domain controllers to reach the prepared state depends on Active Directory latencies and the amount of data that is present in the SYSVOL shared folder.
Important
You should not begin migrating or rolling back to another state until the rollback process reaches a consistent state on all domain controllers.
On each domain controller in the domain, open a command prompt window and then type net share to verify that the SYSVOL shared folder is still shared and that this shared folder still maps to the [drive:\]Windows_folder\SYSVOL folder that FRS is replicating.
Use the Ultrasound tool to verify that FRS replication of the original SYSVOL folder remains healthy. For information about using Ultrasound to monitor FRS replication, see the Ultrasound Help.
If you are not already using Ultrasound to monitor FRS, see the following blog post for a simpler method to check SYSVOL replication using the FRSDIAG tool https://go.microsoft.com/fwlink/?LinkId=137837.
If you are rolling back from the Redirected state to the Prepared state, use the DFS Management snap-in to create a Diagnostic Report for SYSVOL_DFSR folder and confirm that the SYSVOL_DFSR folder is replicating properly. For more information, see Create a Diagnostic Report for DFS Replication.
If you need additional confirmation that the state transition succeeded, perform the additional verification steps in Verifying the State of SYSVOL Migration.