Significantly slower directory tree replication performance when you use the Robocopy command in Windows 7 or in Windows Server 2008 R2

This hotfix adds the following copy options to the Robocopy command:Notes

• The default behavior of earlier versions of Robocopy (the versions that are included in Resource Kits, in Windows Vista, and in Windows Server 2008) is the same behavior as using the /DCOPY:A option.
• The default Robocopy behavior in Windows 7 and in Windows Server 2008 R2 (in the released versions and the hotfixed versions) is the same as using the /DCOPY:DA option.
• To return Robocopy performance to an amount that is closer to earlier versions of Robocopy, you have to add the /DCOPY:A option to all Robocopy commands.
• To improve Robocopy performance even more, use the /NODCOPY optioninstead of the /DCOPY:A option. This provides the best performance, but at the expense of not copying the DOS-style attributes, the extended attributes, and the alternae data streams of directories. Few applications depend on DOS-style attributes for directories. Therefore, if the source directories have no associated extended attributes or alternate data streams, the attempts to copy these attributes and data streams can be safely omitted.
• Copying the NTFS file system access control list security information is requested by specifying the /SEC or /COPY:S option.
  
  Note When you request to copy the security information of files, security information of directories is also copied. This is the same behavior from earlier versions of Robocopy.
• In Windows 7 and in Windows Server 2008 R2, copying security information of directories is only performed the first time that a target directory is copied or created. Earlier versions of Robocopy copied the NTFS access control list security information for all existing directories. However, this created too much NTFRS replication churn if the Robocopy target was also involved in NTFRS replication.
• In Windows 7 and in Windows Server 2008 R2, you can force replication of NTFS access control lists for all directories by adding the /MIR option to Robocopy commands that copy security.
  
  Note/MIR implies /PURGE. Therefore, adding the /MIR option to existing Robocopy commands can cause files and whole directory trees to be deleted if they exist at the destination, but not at the source. Use the /MIR option with caution, because items that are deleted by using /MIR cannot be undeleted.
• In Windows 7 and in Windows Server 2008 R2, you cannot force NTFS access control lists for all directories to replicate unless you specify /MIR and delete additional items from the destination.

Hotfix information

A 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 website:

http://support.microsoft.com/contactus/?ws=support

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.

Prerequisites

To apply this hotfix, you must be running one of the following operating systems:

• Windows 7
• Windows 7 Service Pack 1 (SP1)
• Windows Server 2008 R2
• Windows Server 2008 R2 Service Pack 1 (SP1)

For more information about how to obtain a Windows 7 or Windows Server 2008 R2 service pack, click the following article number to view the article in the Microsoft Knowledge Base:

976932 Information about Service Pack 1 for Windows 7 and for Windows Server 2008 R2

Registry information

To apply the hotfix in this package, you do not have to make any changes to the registry.

Restart requirement

You must restart the computer after you apply this hotfix.

Hotfix replacement information

This hotfix does not replace a previously released hotfix.

File information

The global 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 7 and Windows Server 2008 R2 file information notes

• The files that apply to a specific product, milestone (RTM, SPn), and service branch (LDR, GDR) can be identified by examining the file version numbers as shown in the following table:
  

  Version	Product	Milestone	Service branch
  6.1.760 0.21xxx	Windows 7 and Windows Server 2008 R2	RTM	LDR
  6.1.760 1.21xxx	Windows 7 and Windows Server 2008 R2	SP1	LDR

• The 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 and for Windows 7" section. MUM and MANIFEST files, and the associated security catalog (.cat) files, are extremely important to maintain the state of the updated components. The security catalog files, for which the attributes are not listed, are signed with a Microsoft digital signature.

For all supported x86-based versions of Windows 7

For all supported x64-based versions of Windows 7 and of Windows Server 2008 R2

For all supported IA-64-based versions of Windows Server 2008 R2