The global software-defined storage (SDS) market is projected to grow at a compound annual growth rate of just over 29 percent between now and 2025. The emergence of hyperscale data and the growth in adoption of cloud-based infrastructure and virtualization technologies are major contributors to the rise of SDS. That’s because these technologies all require huge increases in storage capacity.

SDS offers the scalability and flexibility that enterprises need to accommodate the explosion of data volume — and at an affordable price. However, as adoption of software-defined storage grows, it is important for organizations to be knowledgeable about current solutions, both in terms of what is available and what to be wary of.

Compatibility problems, inconsistency issues, or lack of features are all possibilities in today’s SDS market. Any one of these, let alone a combination of them, can create problems.

Below are recommendations for what to avoid and what to look for when deploying a SDS solution that best serves the needs of your organization.

The Benefits of Unified Storage

To get the most out of your SDS offering, a unified system will bring all the “flavors” of storage together. For instance, if your current file-based storage system offers support for object store as well, it can save the hassle of managing and balancing many different complementary storage systems. First, this unified approach is easier to manage; second, it makes better and more efficient use of resources in relation to performance and capacity. It’s similar to virtualization, where you cut back on hardware resources that are idling. By using a unified approach you are using your resources more intelligently.

This sounds like a reasonable approach, but it’s not as easy to identify as one might hope. Some software-defined storage companies claim to offer flexibility and the ability to meet enterprise needs with object, block and file storage, claim to support flash storage, and be both hyper-converged and hyperscale. However, some options lack the features to back up those claims.

Many SDS providers focus on one narrow use case, such as:

• Hybrid cloud,
• Scale-out file systems,
• Hyperconvergence,
• SAN,
• Object storage,
• And archiving

Providers that have a narrow focus for specific use cases can offer their solutions at one-third the price of more comprehensive solutions, but it’s worth noting they also have one-third of the features. In addition, they are not focused on general-purpose network-attached storage (NAS).

The Importance of Consistency

What most organizations need is a general purpose NAS solution that scales well. But just as with SDS solutions, not all NAS solutions are created equal.

Consistency is critical in scale-out NAS, but many organizations are unaware of this fact. Some storage environments are only eventually consistent. This means files written to one node are not immediately accessible from other nodes. Even when the other nodes have been updated to record changes made to the original node, a delay of just fractions of a second can cause problems with accessing applications or users. This can be caused by not having a proper implementation of the protocols or not tight-enough integration with the virtual file system.

The opposite of being eventually consistent is being strictly consistent: files are accessible from all nodes at the same time. The view of the file system through each node is strictly consistent. Any modification on one node is instantly available from any other node. Make sure that your solution can be consistent between protocols as well. That means if you write something in service message block (SMB), for example, it should be immediately visible over network file system (NFS) as well.

SDS Components to Look For

So far, we have covered the need for a unified solution that supports all storage protocols and the need for a strictly consistent NAS. In addition to those features, this is what a comprehensive SDS solution looks like:

• Scalable and flexible — You can start small and later rapidly add multiple virtual machines to the same cluster, eliminating the cost and hassle of building new clusters in order to accommodate scale-out. If a storage cluster is built on a symmetric architecture, linear scaling up to hundreds of petabytes and billions of files is possible, simply by adding more storage nodes to the cluster. Adding storage nodes and increasing capacity can be carried out during runtime and does not interrupt any ongoing operations in the cluster.
• File systems — This type of storage is required to handle unstructured data. Make sure your SDS setup includes crucial file features such as tiering, quota, snapshot, encryption, antivirus, WORM (write once read many), and retention. It should also be able to integrate into Microsoft Active Directory, have support for multiple authentication providers, and enforce authorization checks. If your company is a large one, ensure that the solution has support for multi-tenancy, where you can create multiple file systems in the same environment.
• Disaster recovery — If you choose an SDS solution with a storage cluster that is important to backup, you can protect each of your applications with a unique disaster recovery policy and remain highly available.
  Hardware-agnostic — Being able to use standard commodity storage hardware and servers without a lock-in to a specific vendor and/or technology means you can add additional hardware of your choice as needed to scale performance and capacity over time.
• Hybrid cloud — If you have a local presence and a presence in the cloud, part of your data needs to live-in and be accessed from the cloud as well. For example, part of your local storage system will be exposed to virtual machines running in a public cloud like Amazon. That means your SDS file system needs to cover both environments so you can easily pass files between them.
• Hyperconverged — A software-based architecture integrates compute, storage, networking, and virtualization resources and other technologies on a commodity server.

Know Before You Buy

As data volume skyrockets, so does the need for greater storage capacity. SDS promises to provide scalability at a low cost, but many vendors focus their offerings too narrowly and do not provide critical features. Organizations benefit from a SDS solution that makes use of general-purpose NAS and takes consistency and compatibility into account. Use the recommendations above to research solutions to ensure that your enterprise gets the storage it needs.