Dec 23 2019

VMware vSAN: What Is It, and How Does It Help Businesses?

By pooling capacity from commodity hardware, VMware vSAN can help organizations achieve simple scalability in their data centers.

Simplicity, simplicity, simplicity.

Ask someone about the benefits of VMware vSAN, and this will typically be their top three priorities. But what exactly is the solution, and what does it do? And on a more granular level, how does vSAN support data encryption, what are the advantages of different cluster types, and what’s the difference between an all-flash and a hybrid setup?

Read on for the need-to-know information about why and how organizations are deploying VMware vSAN in their data centers.

DISCOVER: How the State Bar of Wisconsin improved application performance and scalability while keeping costs in check.

What Is vSAN?

The descriptors that get applied to vSAN include “software-based distributed storage solution,” “hyperconverged infrastructure” and “software-defined storage.” Really, it’s all of those things.

“It’s virtual storage that gets deployed as a hyperconverged, software-defined solution,” says Greg Schulz, senior analyst at Server StorageIO.

While the marketplace is rife with hyperconvergence options, what sets vSAN apart is its ability to run on virtually any hardware, as well as its deep and seamless integration with VMware’s other offerings. “If the emphasis is on the software, then the software should be able to run pretty much on anything, anywhere,” Schulz says. “The challenge is, most storage that’s out there today is software-based or software-defined, but it gets packaged with hardware.”

The latest version, VMware vSAN 6.7, represents an evolution in a number of areas, Schulz says. “As the technology is maturing, it’s not always about who is the newest or has the most bells and whistles,” he says. “It’s a combination of new capabilities, but also extending resiliency. This version can scale up, scale down, run with two nodes or a large number. The capabilities are more robust, and the management has gotten easier.”These capabilities have made vSAN the most widely deployed HCI software on the market, with 41 percent of organizations using it, compared with 29 percent for the next most widely deployed software, according to IDC.

What Are the Benefits of Deploying vSAN?

One of the key benefits of hyperconverged solutions such as vSAN is the way they reduce the management load on data center operators, says Eric Sheppard, research vice president within the Enterprise Infrastructure Practice group at IDC. “Broadly speaking, what we’re seeing is that organizations are investing today in modern data center infrastructure with the intention of driving savings longer term, and those savings are generated through operational simplicity, automation and a move toward a scale-out, software-defined, commodity architecture,” he says. “Organizations don’t view a lot of the tasks that are required to manage traditional infrastructure as valuable to their business, or they view those as an impediment to critical change.”

When asked to identify the most significant benefit of vSAN, Schulz gives a tongue-in-cheek answer, saying simply, “It’s VMware.”

“If you’re a VMware environment, and you’re running VMware for your hypervisor, guess what your choice is going to be. You don’t have to go out and layer on someone else’s storage to get that capability.”

Schulz adds that vSAN facilitates ease in diagnostics and troubleshooting, and says the solution offers what he calls a “have-it-your-way” brand of flexibility. Because organizations can opt for either hyperconvergence-specific nodes, or else design their own setup with more standard hardware, vSAN clusters can be architected so that they can easily be expanded while also allowing organizations to limit licensing costs. That’s just one of the ways that vSAN can yield savings in total cost of ownership, Schulz explains. “When you factor in the cost to manage, and the care and feeding, that’s where the cost benefits start to come into play,” he says.

What Are the Key Capabilities of vSAN?

The simplicity of hyperconverged infrastructure, Sheppard says, stems from a number of capabilities and characteristics. “It’s ease of deployment, it’s automating management tasks, it’s self-healing, self-discovery of expanded nodes, the cost-effective way of building out stretched clusters for resilient operations,” he says. “The simplicity starts with initial deployment and goes for day one and day two operations, as well.”Today, Sheppard says, we see more organizations using hyperconverged infrastructure to run their critical workloads — rather than merely as a facilitator for use cases such as virtual desktop infrastructure, which was a common early use case for the technology. “The feature set is far more robust today,” he says. “More and more people are seeing hyperconverged infrastructure now as a platform for hybrid cloud.”

If there’s a power outage or a hardware problem, if something happens to those eggs in one refrigerator, you can keep running.”

Greg Schulz Senior analyst at Server StorageIO.

vSAN Cluster Types: 2 Node Clusters vs. Stretched Clusters

A regular vSAN cluster will reside at one site and requires at least two nodes (although three or more is common). Meanwhile, a vSAN “stretched cluster” divides nodes among multiple sites, which may reside just down the hallway from one another, or may be located in separate buildings on a campus or across a city. Schulz likens a stretched cluster to “taking a 12-egg carton and cutting it in half.

“It’s all about availability,” Schulz says. “If there’s a power outage or a hardware problem, if something happens to those eggs in one refrigerator, you can keep running.”

Schulz notes that organizations may also opt to connect multiple clusters across more distant locations — for instance, connecting clusters in Chicago and New York. While these sites are too distant to accommodate a single stretched cluster, infrastructure at far-flung sites can be set up to replicate to each other, providing a greater level of redundancy.

How Does vSAN Encryption Work?

When organizations enable encryption, vSAN encrypts everything in the vSAN data store. Because all files are encrypted, all virtual machines (as well as their corresponding data) are protected, and only an administrator with encryption privileges can perform encryption and decryption tasks. “Because they’re part of the VMware environment, the nodes themselves have that protection, where it’s difficult to get in there and tinker with the node and the encryption mechanism,” Schulz says. “It’s multiple layers of protection.” 

MORE FROM BIZTECH: Learn about using VMware as a service on Microsoft Azure.

What Are the Differences Between All-Flash vSAN and Hybrid vSAN?

Data center operators can take advantage of vSAN’s features in an all-flash environment or a hybrid configuration. In an all-flash vSAN, flash storage is used throughout the entire solution. A hybrid vSAN, by contrast, uses flash only at the caching layer, with spinning disk storage used throughout the rest of the environment. An all-flash vSAN will, of course, offer an overall higher level of performance, and data center operators should understand that the cost of flash storage has dropped steeply in recent years, making all-flash a realistic option for many use cases. Still, hybrid solutions remain even more affordable, and the decision will ultimately come down to each individual organization’s performance requirements and budget.

“There’s plenty of demand for all-flash, and plenty of people also use hybrid,” says Sheppard. “You absolutely have to have both [as options]. What we’re seeing is that hyperconverged infrastructure has matured to a point where it can’t be a single type of product. It has to be a little broader in terms of how it can be configured by the user.” 

“Get as much flash as you can afford,” Schulz advises. “The price of flash is always coming down, but so is the price of spinning disk. If you can’t afford all the flash you need for your capacity, hybrid is a home run. It’s all about budget.” 

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