What are SOFS and How Do They Help Hyper-V?

In Windows Server 2012 (and R2), Microsoft released the Scale Out File Server (SOFS) feature. SOFS provides highly available file-based storage for applications and general use, and they are particularly well suited for Hyper-V storage.

Scale-out file shares allow the same folder or file to be shared from multiple cluster nodes. If you setup your Hyper-V environment to leverage SOFS and SMB 3.0, your VMs can be accessed simply with a UNC pathname. For example:


SMB 3.0 manages all the load balancing, redundancy and network management for fault tolerance. Also with SOFS clusters, all nodes are active-active, so provisioning additional servers increases performance for your scale-out file shares and services and insures that all compute resources are leveraged in your configuration.

Microsoft touts these key benefits of SOFS:

  • Active-Active file shares – All cluster nodes can accept and serve SMB client requests. This provides transparent failover to alternative cluster nodes.
  • Increased bandwidth – The maximum share bandwidth is the total bandwidth of all file server cluster nodes.
  • CHKDSK with zero downtime
  • Clustered Shared Volume cache – a significant performance boost.
  • Simpler management   With Scale-Out File Server, you create the scale-out file servers, and then add the necessary CSVs and file shares. Much simpler than prior cluster management.
  • Automatic rebalancing of Scale-Out File Server clients  

You can read more details on SOFS on Microsoft’s Technet site.

By leveraging SOFS for your Hyper-V storage, you get a simple storage management interface for your Hyper-V administration (similar to NAS storage) while enjoying performance and availability of typically expensive and complex SANs. In a future post, we will take a look at setting up and managing SOFS.


Discover how Unitrends can help protect your organization's sensitive data