New Windows appliance from Tacit simplifies WAN file-sharing Are storage devices becoming too intrusive? It sure seems that way, doesn’t it? Especially when you consider that even in our private life we interact with numerous storage devices — from listening to our favorite tunes while jogging, to relaxing before our home entertainment center — that make our day more productive and more enjoyable. At least as long as everything goes smoothly, that is. When Murphy’s Law or simple statistical probabilities kick in and something goes wrong, we have to rush to don our thinking caps and become troubleshooters.Diagnosing technical problems is a very ungrateful task in itself — and is even less appealing because often what appears to be a malfunctioning storage device could actually be caused by hiccups in other technologies. Take for example exchanging family photos over the Internet. So many things can go wrong (hint: telecom connection), disappointing Grandma and crashing her expectations of seeing her grandchild standing for the first time.These problems happen outside the easy-going home-computing environment, too. Accessing or storing data remotely has never been a smooth ride for a variety of reasons, including service interruptions, high latency, and frequent errors on the fragile telecom pipe.Nevertheless, the availability of easy-to-deploy networking protocols for Linux/Unix and Windows makes it difficult for companies to resist the temptation of extending file serving from the LAN to the more troublesome WAN environment. It’s easy to see how a WAN file-sharing scenario can quickly be brought to its knees by an occasional service hiccup or be hampered by a slow transfer rate. To remove that inconvenience, companies develop work-arounds, such as using remote replicas to minimize the WAN impact.Obviously, by doing so, storage becomes pervasively deployed across the company, but that’s hardly a trouble-free solution. Remote replicas may very well remove latency and slow transfer rates from WAN file sharing, but they can introduce other delays caused by the need for additional management tasks, such as maintaining remote copies or running backups.In essence, those work-arounds often translate into remote offices still working at a somewhat delayed pace — probably the very same problem that remote file sharing was meant to address. That’s not quite a satisfactory outcome, in my view. If the above scenario sounds familiar, you should know that a startup, Tacit Networks, claims to have a solution called the Ishared appliance, which will make your WAN file-sharing problem disappear without imposing additional management burden.How does the Tacit solution work? You install a server appliance at your HQ and a client appliance at each remote office, as many as 100 client appliances for each server. The two Tacit boxes sit at the WAN edge of each remote connection and provide a cocktail of services, including buffering, compression, asynchronous updates, and differential file changes, to make the most efficient use of the WAN connection.As a result, you can keep just one central copy of company files, leaving the task of smoothing WAN delays for remote users to the Tacit Ishared server and its client appliances. Tacit has been selling a Linux version of Ishared since December 2002, but it released in June a Windows version based on Microsoft Storage Server 2003. The new version should interest the army of CTOs that use Microsoft file sharing and find DFS (distributed file sharing) good at simplifying the directories’ structure but sluggish in performance when applied to remote users.Wondering what kind of improvement you should expect from Tacit Ishared? I swore not to reveal names, but according to Tacit, Ishared customers have measured significant improvements, such as reducing the time to save a 5MB Word file — two minutes or longer over a T1 connection– to just seconds.Obviously, bandwidth and latency are not the only factors affecting file sharing over WAN performance. The loquacity of protocols such as IP cause frequent interactions that are almost unnoticeable over a LAN but take a heavy toll on remote users. To minimize that toll, the Ishared appliances communicate using a proprietary protocol SC/IP (storage caching over IP), which Tacit says makes file sharing for remote users almost as smooth and responsive as if they were locally connected, which, in fact, they are. Using SC/IP, Tacit can seamlessly maintain reasonably recent copies of company files on remote Ishared appliances and quickly fetch updates from the server when needed.But the server and clients need only know familiar Unix or Windows file-sharing protocols, which makes the solution from Tacit quite unique, because it offers the best of two worlds: pervasively distributing storage and seamlessly sharing files without introducing complicated management issues or asking users to troubleshoot their storage network. It’s definitely worth a look.