Dfsrmig.exe

[Laila Berri]

Themigration tool for the DFS Replication service, dfsrmig.exe, is installed with the DFS Replication service. This tool migrates SYSvol replication from File Replication Service (FRS) to Distributed File System (DFS) Replication. It also provides information about the progress of the migration and modifies Active Directory Domain Services (AD DS) objects to support the migration.

Important: You should only run this command on the PDC emulator./getmigrationstateRetrieves the current local migration state for all domain controllers in the domain and determines whether those local states match the current global migration state. Use this option to determine if all domain controllers have reached the global migration state./createglobalobjectsCreates the global objects and settings in AD DS used by DFS Replication uses. The only situations where you should use this option to manually create objects and settings, are:A new read-only domain controller is promoted during migration. If a new read-only domain controller is promoted in the domain after moving into the Prepared state, but before migration to the Eliminated state, then the objects that correspond to the new domain controller aren't created, causing replication and the migration to fail.Global settings for the DFS Replication service are missing or were deleted. If these settings are missing for a domain controller, migration from the Start state to the Prepared state will stall at the Preparing transition state. Note: Because the global AD DS settings for the DFS Replication service for a read-only domain controller are created on the PDC emulator, these settings need to replicate to the read-only domain controller from the PDC emulator before the DFS Replication service on the read-only domain controller can use these settings. Because of Active Directory replication latencies, this replication can take some time to occur./deleterontfrsmember []Deletes the global AD DS settings for FRS replication that correspond to the specified read-only domain controller, or deletes the global AD DS settings for FRS replication for all read-only domain controllers if no value is specified for .You shouldn't need to use this option during a normal migration process, because the DFS Replication service automatically deletes these AD DS settings during the migration from the Redirected state to the Eliminated state. Use this option to manually delete the AD DS settings only when the automatic deletion fails on a read-only domain controller and stalls the read-only domain controller for a long time during the migration from the Redirected state to the Eliminated state./deleterodfsrmember []Deletes the global AD DS settings for DFS Replication that correspond to the specified read-only domain controller, or deletes the global AD DS settings for DFS Replication for all read-only domain controllers if no value is specified for .Use this option to manually delete the AD DS settings only when the automatic deletion fails on a read-only domain controller and stalls the read-only domain controller for a long time when rolling back the migration from the Prepared state to the start state./?Displays help at the command prompt.RemarksUse the /setglobalstate command to set the global migration state in AD DS on the PDC emulator to initiate and control the migration process. If the PDC emulator isn't available, this command fails.

Migration to the Eliminated state is irreversible and rollback isn't possible, so use a value of 3 for state only when you are fully committed to using DFS Replication for SYSvol replication.

Active Directory replication replicates the global state to other domain controllers in the domain, but because of replication latencies, you can get inconsistencies if you run dfsrmig /getglobalstate on a domain controller other than the PDC emulator.

The output of dfsrmig /getmigrationstate indicates whether migration to the current global state is complete, listing the local migration state for any domain controllers that haven't yet reached the current global migration state. The local migration state for domain controllers can also include transition states for domain controllers that have not reached the current global migration state.

Read-only domain controllers can't delete settings from AD DS, the PDC emulator performs this operation, and the changes eventually replicate to the read-only domain controllers after the applicable latencies for active directory replication.

The dfsrmig command is supported only on domain controllers that run at the Windows Server domain functional level, because SYSvol migration from FRS to DFS Replication is only possible on domain controllers that operate at that level.

You can run the dfsrmig command on any domain controller, but operations that create or manipulate AD DS objects are only allowed on read-write capable domain controllers (not on read-only domain controllers).

To display information about whether the local migration states on all the domain controllers match the global migration state and if there are any local migration states where the local state doesn't match the global state, type:

To create the global objects and settings that DFS Replication uses in AD DS on domain controllers where those settings were not created automatically during migration or where those settings are missing, type:

In our first post in this series, we examined the SYSVOL migration process and understood how things work at a high level during the process of migration of the SYSVOL share from the FRS service to the DFS Replication service. Windows Server 2008 includes a command line tool called dfsrmig.exe which can be used by administrators to control the process of migrating replication of the SYSVOL share from FRS to the DFS Replication service. In this post, we take a closer look at this tool. The following posts in this series will explain how to migrate replication to each of the migration states in greater detail.

The dfsrmig.exe tool is supported only on domain controllers which are running in the Windows Server 2008 domain functional level. This is because SYSVOL migration from FRS replication to the DFS Replication service is possible only on domain controllers operating in the Windows Server 2008 domain functional level.

These are the set of command line switches which will be used frequently during the migration process. For the most part, the remaining command line switches (called Auxiliary/Optional switches) should not be required during the course of a typical migration process.

This command line switch can be used to initiate and control the migration procedure by setting the migration global state (explained in this post ) in Active Directory on the Primary Domain Controller. The value set for the migration global state drives the process of SYSVOL migration.

Active Directory replication enables the value of the global migration state to be replicated to the individual domain controllers in the domain. When the DFS Replication service on any of these individual domain controllers polls its Active Directory for configuration information, it notices the migration directive (value of the global migration state) and then takes steps locally to match its local migration state with the currently configured global migration state.

If the Primary domain controller is not available, this command fails. Since this command line switch is used to set the global migration state for the domain, the only permissible parameters to this switch are the global migration states detailed below.

This command retrieves local migration state related information from all the domain controllers and matches it with the current global migration state that has been set for the domain on the primary domain controller. It then proceeds to summarize the results and displays whether migration is complete or pending on all domain controllers. It also mentions which domain controllers in the domain have not yet reached the global migration state set for the domain and specifies the local migration state those domain controllers are currently in.

These command line switches are not required during the course of a regular migration procedure from the FRS service to the DFS Replication service. However, there are some exceptional circumstances which are described below in which these command line switches come in handy for domain administrators performing SYSVOL migration. These command line options are for the most part applicable only to read only domain controllers.

If this command is run without any parameter, the FRS global settings for all RODCs are deleted. The administrator can also explicitly pass in the name of the RODC whose FRS global settings are to be deleted.

Windows Server 2003 and 2003 R2 uses File Replication Service (FRS) to replicate SYSVOL folder content to other domain controllers. But Windows server 2008 and later are using Distributed File System (DFS) for the replication. DFS is better than FRS.

The current domain functional level is not at least Windows Server 2008.

DFSRMig is only supported on at least Windows Server 2008 level domains.

PS C:\Users\Administrator> dfsrmig.exe /GetGlobalState

Windows Server 2008 ships a command line tool called dfsrmig.exe which can be used by administrators to migrate from NTFRS replication of the SYSVOL folder to using DFSR for replication of SYSVOL. This can be done once the domain functional level has been raised to Windows Server 2008 or above.

A great step-by-step guide to using the DfsrMig.exe tool can be found at -Server-2008-Directory-Services-SYSVOL-DFS-Replication.htm or an even more thorough series of posts start here: -migration-series-part-1-introduction-to-the-sysvol-migration-process.aspx

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