Storage Spaces Direct

Storage Spaces Direct, or S2D, is a feature introduced by Microsoft in Windows Server 2016 that makes it possible to easily enable the creation of highly-available (HA) storage systems with local storage.  The primary goals of S2D are to help simplify the deployment and management of software-defined storage systems as well as to open the use of new classes of disk devices like SATA and NVMe (Non-Volatile Memory Express), which were previously not able to be used with clustered Storage Spaces with shared disks.

Simply stated, Storage Spaces Direct can use disks internal to nodes in a cluster or it can directly attach to nodes in a cluster via an enclosure, making it more affordable for administrators to create redundant and flexible disk storage. Storage Spaces aggregates the disks local to the cluster nodes, which creates a Storage Pool of these disks and enables virtual disks to be created.  These virtual disks can be used as a Cluster Shared Volume (CSV) that can house Hyper-V virtual machines (VMs) running on ReFS-formatted volumes.

The concept of “storage spaces” may actually sound familiar to those of you familiar with features of earlier operating systems. Microsoft provided Storage Spaces in Windows Server 2012/2012R2 as a first building block for software-defined storage (SDS). Windows file servers sharing out storage over the SMB 3.0 protocol, clustered together for high availability and performance, backed by SAS-attached external storage chassis with hard disk drives (HDDs) and solid state drives (SSDs) in tiered storage, provided an alternative to costly SANs while being easier to set up and manage.

Despite all their best efforts, Storage Spaces wasn’t a huge success.  This was due in part to the fact that traditional vendors didn’t have the desire to sell cost-effective storage; they were focused on selling only expensive SANs. Another issue was that Storage Spaces was really only a good solution for medium to large deployments where three or four separate servers, along with shared disk trays, made financial sense.

Storage Spaces Direct focused on these issues. To provide better scaling opportunities, instead of using external disk trays, internal storage in each server is pooled together. When you find you need more storage, simply add another server. It also presents more options for different types of storage, such as cost effective SATA SSDs and HDDs (as well as SAS) and non-shareable data storage such as NVMe.

So, how does it work?

Storage Spaces Direct was designed for two distinct deployment options:

1.     Converged:

Storage and compute in separate clusters. The converged deployment option, also known as ‘disaggregated’, layers a Scale-out File Server (SoFS) atop Storage Spaces Direct to provide network-attached storage over SMB3 file shares. This allows for scaling compute/workload independently from the storage cluster, essential for larger-scale deployments such as Hyper-V IaaS (Infrastructure as a Service) for service providers and enterprises.

2.     Hyper-Converged:

One cluster for compute and storage. The hyper-converged deployment option runs Hyper-V virtual machines or SQL Server databases directly on the servers providing the storage, storing their files on the local volumes. This eliminates the need to configure file server access and permissions, and reduces hardware costs for small-to-medium business or remote office/branch office deployments. See Deploy Storage Spaces Direct.

Hyper-Converged Infrastructure is the fastest-growing segment of the on-premises server industry. By consolidating software-defined compute, storage, and networking into one cluster, customers benefit from the latest x86 hardware innovation and achieve cost-effective, high-performance, and easily-scalable virtualization.

Not only did Windows Server 2016 and its Storage Space Direct technology recently win Product of the Year from Computer Reseller News for the Software-defined Storage category (December, 2017), even more recently (March, 2018) Microsoft also announced they reached an exciting milestone:

“There are now over 10,000 clusters worldwide running Storage Spaces Direct! Organizations of all sizes, from small businesses deploying just two nodes, to large enterprises and governments deploying hundreds of nodes, depend on Windows Server and Storage Spaces Direct for their critical applications and infrastructure.”

You can find references to this information, as well as more details at the following locations:

Check out this YouTube video published by Microsoft Cloud Platform for some more information on Storage Spaces Direct:

If you’d like to learn more about S2D and additional storage options and features in Windows Server 2016, attend a course with LRS Education Services!

The following Microsoft courses are recommended:

MS20740 – Installation, Storage, and Computer with Windows Server 2016

MS20743: Upgrading Your Skills to MCSA: Windows Server 2016

Check out our course schedule for upcoming dates!

We’d love to have you attend in person, virtually, or by using the Microsoft On-Demand (MOD) training format.  And in case you didn’t know, however you choose to attend these courses, you will also receive a FREE Pearson Vue Certification exam voucher to get you moving down the road to certification!

If you have any questions or would like more information regarding courses scheduled at LRS Education Services, please call 877 832.0688 ext: 1493 or email us at


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