DFS Replication does not use Remote Differential Compression (RDC) when replicating very large files on a computer that is running Windows Server 2008 R2
Consider the following scenario:
- You install the Distributed File System (DFS) Replication service under the File Services role on some computers that are running Windows Server 2008 R2.
- You configure one or more replicated folders between these computers by using the DFS Management Microsoft Management Console (MMC) snap-in.
- These replication folders contain some large files such as a virtual hard disk (VHD).
- These files are changed on one of the computers after the files have replicated out.
- This issue only applies to very large files such as VHDs.
- In some instances, nothing is downloaded to the replication partners when some changes occur to these large files.
For very large files, the DFS Replication service incorrectly marks a file download operation as finished before the file is completely downloaded. Therefore, the file is not replicated by using the Remote Differential Compression algorithm correctly. When the DFS Replication service notices that the whole download operation is not completely downloaded, DFS Replication that is located on the receiving member downloads the whole file from the sending member.
Hotfix informationA supported hotfix is available from Microsoft. However, this hotfix is intended to correct only the problem that is described in this article. Apply this hotfix only to systems that are experiencing the problem described in this article. This hotfix might receive additional testing. Therefore, if you are not severely affected by this problem, we recommend that you wait for the next software update that contains this hotfix.
If the hotfix is available for download, there is a "Hotfix download available" section at the top of this Knowledge Base article. If this section does not appear, contact Microsoft Customer Service and Support to obtain the hotfix.
Note If additional issues occur or if any troubleshooting is required, you might have to create a separate service request. The usual support costs will apply to additional support questions and issues that do not qualify for this specific hotfix. For a complete list of Microsoft Customer Service and Support telephone numbers or to create a separate service request, visit the following Microsoft Web site: Note The "Hotfix download available" form displays the languages for which the hotfix is available. If you do not see your language, it is because a hotfix is not available for that language.
PrerequisitesTo apply this hotfix, your computer must be running Windows Server 2008 R2. Additionally, the DFS Replication service under the File Servers role must be installed.
Installation instructionsWarning Serious problems might occur if you modify the registry incorrectly by using Registry Editor or by using another method. These problems might require that you reinstall the operating system. Microsoft cannot guarantee that these problems can be solved. Modify the registry at your own risk.
After you install this hotfix, you must create the following registry key:
Note This value of the registry key represent 4 hours in milliseconds.
Restart requirementYou must restart the computer after you apply this hotfix.
Hotfix replacement informationThis hotfix does not replace a previously released hotfix.
File informationThe English (United States) version of this hotfix installs files that have the attributes that are listed in the following tables. The dates and the times for these files are listed in Coordinated Universal Time (UTC). The dates and the times for these files on your local computer are displayed in your local time together with your current daylight saving time (DST) bias. Additionally, the dates and the times may change when you perform certain operations on the files.
Windows Server 2008 R2 file information notesThe MANIFEST files (.manifest) and the MUM files (.mum) that are installed for each environment are listed separately in the "Additional file information for Windows Server 2008 R2" section. MUM and MANIFEST files, and the associated security catalog (.cat) files, are critical to maintaining the state of the updated component. The security catalog files, for which the attributes are not listed, are signed with a Microsoft digital signature.
For all supported x64-based versions of Windows Server 2008 R2
|File name||File version||File size||Date||Time||Platform|
|Dfsrprovs.mof||Not Applicable||75,200||13-Jul-2009||20:20||Not Applicable|
Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.
You can use Performance Monitor to track the following Remote Differential Compression feature-related counters on the downstream members. When the issue occurs, the files are replicated. But the values of these counters are not increased.
- DFS Replicated Folders\RDC Number of Files Received
- DFS Replicated Folders\RDC Bytes Received
DFS Replicated Folders\Size of Files ReceivedFor more information about software update terminology, click the following article number to view the article in the Microsoft Knowledge Base:
824684 Description of the standard terminology that is used to describe Microsoft software updatesFor more information about Remote Differential Compression, visit the following Microsoft Web site.
Additional file information
Additional file information for Windows Server 2008 R2
Additional files for all supported x64-based versions of Windows Server 2008 R2
|File name||File version||File size||Date||Time||Platform|
|Amd64_a0b53a404659b9e3a63865b85d38d080_31bf3856ad364e35_6.1.7600.20578_none_f04a3152a67e2679.manifest||Not Applicable||712||18-Nov-2009||19:27||Not Applicable|
|Amd64_microsoft-windows-dfsr-core-serveronly_31bf3856ad364e35_6.1.7600.20578_none_fa181218da8b2221.manifest||Not Applicable||35,681||18-Nov-2009||19:27||Not Applicable|
Article ID: 975763 - Last Review: 01/07/2010 07:20:14 - Revision: 2.1
Windows Server 2008 R2 Datacenter, Windows Server 2008 R2 Enterprise, Windows Server 2008 R2 Standard
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