Using Offline Files with Samba / EMC Servers, & NAS Devices

We’ve seen numerous questions lately regarding the use of Offline Files against a NAS device. Customers report that Windows XP clients work fine against a particular NAS device but Windows Vista clients do not. The reason for this difference is that Offline Files in Windows Vista relies on file system behaviors that the XP implementation did not utilize, so if those features are not correctly implemented by the server, Vista can encounter problems.

Many NAS devices use Samba to provide Windows file sharing functionality, so the Samba configuration requirements below also apply to them.

The Offline Files team has provided the following tips for enabling Offline Files against a Samba / NAS device:

• Verify that the server / device is running Samba 3.0.22 or later. Earlier versions cannot work correctly with Vista Offline Files due to implementation bugs.
• Enable oplocks by adding the following to the Samba configuration file:
• o oplocks = yes
• o level2 oplocks = yes
• o (for level 2 oplocks) kernel oplocks = no
• Enable hidden/system/archive attributes for files by adding the following to the Samba configuration file:
• create mask = 777
• map archive = yes
• map system = yes
• map hidden = yes
  
  Note: Even with these changes, the hidden/system/archive attributes will not work for directories.
  
  
• Set the following registry key on the Windows Vista client to prevent files from getting pulled down to the client again right after synchronizing changes to the server (due to Linux file systems having coarser timestamp resolution than Windows):
• Create a DWORD value named RoundUpWriteTimeOnSync under the HKLM\Software\Microsoft\Windows\CurrentVersion\NetCache key (create the key if it does not exist) and set it to 1.

The Offline Files team has provided the following tips for enabling Offline Files against an EMC server:

• Ensure that your EMC system software is NAS code 5.5.27.5 or greater.

Reminder
File-level based storage on non-Windows devices is not supported by Microsoft. Only devices that have been qualified by the Windows Hardware Qualification Laboratory under the Server category are supported by Microsoft for file-based storage. While Microsoft can enable this deployment, the support is assumed 100% by the hardware device vendor in the case of non-Windows devices