Sanbolic has launched filesystem software that clusters Windows Storage Servers allowing many more write operations - and filling a gap left by Microsoft's own software.

Microsoft's Windows Storage Server 2003 R2 is a server platform specifically for network-attached storage (NAS) and is based upon a Windows Server 2003 R2 base. As the amount of storage behind a Storage Server instance increases then the server can become a bottleneck, particularly with write operations, as accessing hosts send more and more I/O requests to the storage.

One answer is to cluster storage servers together. Microsoft has its own server clustering technology; Windows Compute Cluster Server 2003, which, Microsoft states, 'brings the supercomputing power of high-performance computing (HPC) to the personal and workgroup level.'

This renders it unsuitable for clustering NAS servers together as, for the increased I/O benefits to emerge, the storage behind the NAS servers has to be logically grouped together in a single filesystem. It means any NAS server can write to any part of the storage.

With Sanbolic's Melio FS, multiple Windows Storage Server file serving appliances can be clustered into a common file system on external SAN storage. All Storage Servers have concurrent read and write access to the shared storage using Sanbolic’s clustered file system, so a file call can be processed by any of the Storage Servers.

Melio FS now fully implements the network redirector oplock protocol; this defines interactions between the file system and the network sharing service. It enables the clients to cache, via their network redirector, in clustered file serving installations, and greatly improves performance in network operations such as file open, file attributes updates, and file data write.

This architecture yields enormous increase in performance as network communication is no longer required for each operation. For example, an application writing 200 byte blocks would not wait for a network round-trip time for each write, but the data would be grouped and sent asynchronously to the Storage Server running Melio FS, without blocking the application.

Bala Kasiviswanathan, Microsoft's director of Storage Solutions Marketing, said: “This enhancement provides greater scalability of the performance of Windows Storage Server-based file serving solutions for demanding write-intensive applications.”

Melio FS costs around $2,500 per server (£1,250 at standard conversion rates) from Sanbolic channel partners.