Making Things Mesh (even with Windows Home Server)

I've been playing around with the beta of Windows Live Mesh and I must say I'm very impressed with the possibilities of this product. To break it down, the beta currently offers two main features: Remote machine access, and file and folder synchronization. Remote access is handy, but fairly straightforward and nothing new. What I really want to talk about is the folder sync functionality.

Folder synchronization has been around for a long time, too, so what makes Live Mesh so special? A few things, primarily:

1. You can select any existing folder in your file system for synchronization. For example, you can take your Windows-default Favorites folder from your PC and add it to your Mesh for synchronizing with your laptop.

2. The folder that is synced from one machine does not have to be the same folder on another. Using the above example, when you add the Favorites Mesh folder to your laptop, you are not required to use the same Windows-default Favorites folder for synching. You can create a completely new folder anywhere on your computer that will be synchronized with the Favorites folder from your PC.

3. Folders that you add to your Mesh are also synchronized with the "cloud", up to 5 GB worth (currently). The contents of those folders are accessible from anywhere via web browser, in what is called your Live Mesh Desktop. If you exceed the 5 GB limit, contents will still be synced between devices via P2P, but will not sync with the Live Mesh Desktop.

4. You can invite anyone to share in any of your Mesh folders. That person, once signed up to Live Mesh, will have access to that folder on their Live Mesh Desktop, and if they install the Live Mesh client, can synchronize it automatically to their computer. A person only has access to the folders that you specifically invite them to share in.

Being a huge fan of Windows Home Server, my thoughts immediately turned to how I could use this to synchronize my laptop with my document share on WHS (the built-in Windows synchronization with shares is not available to Windows Vista Home Premium, only Business and Ultimate). I did read that it is possible to install the latest beta verion of Mesh on Windows Server 2003 (which is what WHS runs), but that sharing the folders from the D: drive is not recommended, since all warnings about WHS say that you should access everything from the Windows Shares. I decided to investigate further, despite the warnings.

For backround, WHS uses a technology called Drive Extender (DE), which allows users to add disks to the server, which get added to the storage pool without concern for drive letters or RAID configuration. The Drive Extender Whitepaper explains that DE uses the D: drive (a partition of the system disk) to store symbolic links to the actual files which reside on other volumes which are not mapped to drive letters. Various background services balance the files between drives and duplicate them if that feature is enabled.

Nothing I read indicates that there are any filters operating at the Windows Share (CIFS/SMB) level. Assuming that those Windows Shares are simply run-of-the-mill shares pointing to shared folders on D:, then that means NTFS and the DE filter handle all the low-level file functions, redirecting the symbolic links to the actual file locations. Following that logic, I can't see any reason that another file sharing technology, in this case Windows Live Mesh, cannot operate on those folders the same way that the Windows shares do.

I took the dive, installed Live Mesh, and added a subfolder under my share to the Mesh. The initial synchronization to my Live Mesh Desktop was successful, and then I added it to my laptop as my Windows-default Documents folder. The synchronization there was also successful.

Finally, I ran a test by reorganizing and adding some files to my local Documents folder. Within a few minutes, those changes were reflected in the shared folder perfectly. I have been running this synchronization for about a week now, and WHS has had no problems working with those files, balancing them, or duplicating them. Apparently, my assumption was correct.

Having said and done all that, I do not recommend going against the warnings of Microsoft and the WHS community at large, however this experiment was extremely helpful in understanding at what levels the Drive Extender technologies work. I especially would not recommend doing anything similar for software that works at any level lower than the top-most layers of the file system, e.g., keep virus scanners and disk defragmenters away from your D: drive.

It should also be noted that the Windows Live Mesh client only works when it is run interactively by a user. I tried to run it as a Service (with Administrator's credentials) using AnyServiceInstaller, but it would not sync any folders. Additionally, opening the Console from a client computer does not execute anything in the Startup folder nor anything in the Run registry keys. To get the automatic syncing working, I added a shortcut to Live Mesh to Advanced Admin Console, so I can start it from there after any server reboots, since once the WHS Console has been opened from a client machine, it remains open in an interactive user session on the server, so Live Mesh also keeps running in the background of an interactive login. It's not a perfect solution, but it works.

I'm very interested in the possibilities presented by Live Mesh and I will be very interested to see how Microsoft plans to extend the functionality to smart phones, which they seem to be working on.