Initial snapshot generation may fail if network redirector caching is enabled (285997)

SYMPTOMS

During the generation of a dynamic snapshot for a merge publication, the snapshot generation may fail, and you receive the following error messages.

Error message 1

Agent_id:1
Run_Status:6
Error :The process could not create file ' \\share\repldata\Filename.dri"

Error message 2

Agent_id:1
Run_Status:6
Error: The process encountered operating system error 'The specified network name is no longer available.

The following error message may be in the Microsoft Windows NT system event log:

Event ID: 26
Description: System Process - Lost Delayed-Write Data : The system was attempting to transfer file data from buffers to \device\lanmanredirector.The write operation failed and only some of the data may have been written to the file.

These error messages occur mostly when the snapshot folder location is a universal naming convention (UNC) share. If the snapshot location is a file path, the error messages do not occur.

Note These error messages will be logged in the snapshot agent output.

CAUSE

The network redirector, the Rdr.sys file, caches data locally for files that it accesses on a Microsoft networking server. When SQL Server generates the snapshot, SQL Server tries to write the snapshot files to the UNC share or to the drive location. If network redirector caching is enabled, SQL Server tries to cache the snapshot files before flushing the snapshot to the disk. If the snapshot is extremely large, the problem occurs.

WORKAROUND

To work around this problem, use one of the following methods.

Method 1

If the publisher and the distributor are on the same computer, use file paths such as C:\Replication\Repldata. You can still share the snapshot folder as \\Computer name\Repldata so that other users can access the snapshot folder.

Method 2

If you want to bypass the network redirector, use a file path instead of the UNC share for the snapshot folder location.

Method 3

If the snapshot location is a file path, make sure that the account under which the distribution agent or the merge agent is running has appropriate permissions to access the snapshot folder.

Method 4

If you use a UNC share for the snapshot folder, disable network redirector caching.

For additional information about how to disable network redirector caching, click the following article number to view the article in the Microsoft Knowledge Base:

163401 How to disable network redirector caching