We were trying to write some machine images to a Server 2008 share with Acronis True Image.? True Image would see the shares, but would fail with a strange “bad file name” error.

It turned out to be the same issue that stopped Mac OS 10.4 from talking to my Server 2008 shares at a different location:? the security policies on Server 2008 require SMB message signing.? Both Mac OS 10.4 and the version of True Image that we’re running don’t support SMB message signing.

Here’s how we disabled the message signing requirement (SMB messages will still be signed when a client supports it):

1. Open Group Policy Management and edit the Default Domain Controller Policy
2. Go To Computer Configuration, Policies, Windows Settings, Security Settings, Local Policies, Security Options
3. Scroll down and find the entry Microsoft network server: Digitally sign communications (always)
4. Set this option to Disabled
5. Execute gpupdate on the DC and the file server to apply the new GPO ruleset.