Friday, April 8, 2011

Mac OS X 10.7 Lion now with DFS support

While customers in a home setting would never notice, those in enterprise or education were far too aware of the glaring omission of support for Microsoft's DFS (Distributed File System) in Apple's SMB/CIFS implementation.

For institutions in which cross-platform environments were the norm they would generally have to build their entire file share technology around this limitation. Rather than having the ability to organize shares into logical units, or even include the ability for transparent fail over, only direct top level shares could be created (sometimes creating an unmanageable sea of directories). For those that chose to implement DFS irregardless of the Mac's ability it would usually then necessitate expensive licensing from add-on products such as Thursbys ADmitMac to provide the needed DFS capability.

After extensive testing here at Go Go we can safely say that 10.7 lion has support for DFS which should help ease the burden of enterprise storage administrators as they move forward. The man pages relating to the newly created SMB utilities in Lion also directly reference DFS. From the man page of 'smbutil':
dfs smb://[domain;][user[:password]@]server/DfsRoot[/DfsLink]
Display the Dfs referrals for this URL for the authenticated session.

Great news indeed.

Go Go


  1. Thanks for posting this! I've not found anywhere else that talks about DFS support in 10.7. Could you explain further the testing you did? Lack of DFS support is the single biggest issue I have with Mac OS X in my Windows server environment.

    There are a couple of specific questions that come to mind. Does finder fully support browsing and connecting to DFS paths? If you are already authenticated to AD, do you need to supply the username and password in the CLI commands? I currently have Unix scripts that mount my user's shares that run in the background and they use the currenly logged in user's credentials.

  2. But can you use DFS Home directories in AD

  3. You may be interested in this tool that allows you to connect to DFS shares from Snow Leopard:

  4. I haven't been able to successfully access a dfs share on my Windows 2008 R2 server from any 10.7.x client. The OSX are standalone boxes, not joined to the domain. Neither SL nor Leopard had this problem. Running the command from terminal anytime the user rebots her/his box is NOT an option. Ideas would be appreciated...

  5. DFS shares are excruciating slow on lion, forget it...