SQL Server 2008 Filestream Win32 error without a network cable!

Question

I have a SQL Server 2008 database utilizing Filestreaming and all works fine and dandy apart from under one very strange circumstance. If i have my database on, say a laptop, on a locally installed version of SQL Server 2008 and am connected to the network all works fine. If i unplug the network cable, after a while the SqlFileStream class fails to initialize with a Win32 exception (everything else about connecting to the database works fine). If i start fresh without a network cable it will not work with the same error. If i plug a network cable in even with no network connectivity it works... take it out, nothing.

I'm connecting to the filestream in the usual documented method

SqlFileStream fileStream = new SqlFileStream(path, 
                                             context, 
                                             FileAccess.ReadWrite,  
                                             FileOptions.SequentialScan, 
                                             0);

geting the path and context from a stored procedure which generates them in the following

SELECT Data.PathName(), GET_FILESTREAM_TRANSACTION_CONTEXT() 
  FROM dbo.DocumentFiles
 WHERE [File_ID] = @FileId

I'm getting the following error when creating the SqlFileStream instance

Win32Exception occurred The network location cannot be reached. For more information about network troubleshooting, see Windows help.

No inner exception.

I have tried so many things to resolve the issue with no luck. no one in google-land seems to have the same issue so obviously something silly I'm doing. If anyone can shed any light on this i would be most grateful.

James

Answer 1

Hmm. It looks like your network interface goes down when you unplug your cable. When it happens TCP/IP stack goes down as well since there's no more available interfaces left. I suggest you to to install the MS Loopback adapter, this article explains how to do it in Windows XP; it is easy to google about how to do it in other OSes. Do not forget to assign a static IP to it after installation, private address like 192.168.1.x would be sufficient. Since loopback adapter is a virtual one, it is in "Up" state all the time, even when you unplug your cable and it prevents Windows from shutting TCP stack down.