Currently, there's no way to configure the timeouts for a DFS (distributed file services) client's caches. Windows servers have this configurable (see https://msdn.microsoft.com/en-us/library/cc753923.aspx for details). OES servers have those settings hardcoded.

Here's what happens with OES11:

When the client resolves a DFS link, the server returns a referral path in SMB_COM_TRANS2_GET_DFS_REFERRAL response.

The referral path is a UNC path:
\\NETBIOS_SERVER_NAME\SHARE\SUBDIRECTORY
( file://\NETBIOS_SERVER_NAME)

The client will need to resolve the NETBIOS_SERVER_NAME

If the client does that per DNS, it expects the host at the resolved IP address runs the 'direct-host' CIFS protocol, which listens at TCP port 445.

But the Novell CIFS server on OES11SP2 only supports NetBIOS CIFS, so it does not listen at TCP port 445 for incoming connections and hence the connection will fail.

The client will retry a few times before giving up and that causes a noticeable delay. This delay happens again and again, currently based on the hardcoded default timeout (5 minutes). This makes the file access seem slow to the end users, even though it's simply a name resolution thing and not the file access itself.

Increasing the timeout would make the delay happen less frequently, thus improving the overall responsiveness.

The Novell CIFS server on OES2015 supports the direct-host CIFS protocol so the client can connect successfully with this service at TCP port 445, but we need this functionality in OES11SP2 (as well as OES2015).

by: Jürgen W. | over a year ago | Samba/CIFS