Choosing the MS DTC Log File Location

Applies To: Windows Server 2008

The Microsoft Distributed Transaction Coordinator (MS DTC) log file is in the %windir%\system32\Msdtc directory by default.


On computers running Windows 2000 and Microsoft Windows NT®, the MS DTC log file is in the %windir%\system32\DTCLog directory by default.

The following guidelines suggest ways that you may be able to enhance the performance, reliability, and cluster availability of your computer if you decide to move the MS DTC log file to a new location:

  • Performance

    On extremely high-performance transaction processing systems, you may want to move the MS DTC log file to a dedicated device or a device with relatively little traffic. However, on most systems, it is sufficient to locate the MS DTC log file on any disk with free space that is not used excessively.

  • Reliability

    For maximum reliability, we recommend that you move the MS DTC log file to a RAID-1 device. Losing a MS DTC log file may cause the MS DTC to lose track of pending transactions, which can affect the data consistency of the transaction-protected databases, message queues, and files that are coordinated by the MS DTC. On a RAID-1 device, Write operations to a log file are made to both the primary disk and to a mirror copy of that disk. Because Write operations are concurrent, the elapsed time for writing to a MS DTC log file is little more than writing to a single device. Because writing to a MS DTC log file is synchronous and sequential, this operation is ideally suited to RAID-1 devices. Using a RAID-1 device is also ideal for a MS DTC log file because it provides fault tolerance. If one of the disk drives in the mirrored pair fails, the MS DTC continues to use the surviving disk drive.

    You can implement RAID-1 through either hardware or software. Windows 2000, Windows XP, Windows Server 2003, Windows Vista, and Windows Server 2008 provide a software-based implementation of RAID-1. Using the software-based RAID-1 capability is usually sufficient because it imposes little processing overhead on your system.

  • Cluster availability

    On a clustered system, you must locate the MS DTC log file on a shared disk. This enables the MS DTC transaction manager to access the MS DTC log file regardless of which cluster node the MS DTC transaction manager is running on.