Traditional SAN and Virtual SAN (vSAN): What to Choose?

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Whether it’s time to deploy a platform for new projects, set up a CRM server, or build a data center suitable for an industry-standard hypervisor, there comes a time in every IT manager or storage administrator’s career when they’re confronted with this question: “Should I use a traditional SAN appliance or get a vSAN solution?” In this blog post, we’ll overview the two SAN solutions, differentiate between the two, and come up with an answer about which one should you choose for your projects.

What Are Traditional SAN Appliances?

Quick Definition: High-performance block-mode iSCSI or Fibre channel physical storage appliances for hosting industry-standard hypervisors or running databases and applications.

In-Depth Explanation: Typically available from 4-bay tower to 36-bay rackmounts, traditional SAN appliances use iSCSI and/or Fibre Channel (FC) protocols to deliver high-performance block-mode storage for structured workloads.

Examples of structured workloads include:

  • Databases: MySQL, Oracle, NoSQL, PostGreSQL, etc.
  • Applications: SAP HANA, or other large CRM or EHR software
  • Large deployments of industry-standard hypervisors like VMware ESX/ESXi, Microsoft Hyper-V, Windows Server Standard (or Datacenter) 2016/2019, KVM, Citrix (formerly XenServer), or StoneFly Persepolis

Confused about the difference between block storage and file storage? I recommend giving this a read.

When to Use a Traditional SAN Appliance?

On-premises SAN appliances are a great choice for large deployments for critical workloads with a low tolerance for latency.

In addition to overcoming latency challenges, local SAN appliances deliver more control in terms of administration, spin up, and physical appliance security, as required by many regulatory authorities. Furthermore, SAN appliances can scale to hundreds of terabytes to petabytes of storage capacity and proportional performance capability. In terms of ROI, if you are running workloads that have the potential to grow to such a scale, on-premises SAN appliances are the better choice.

That is not to say that they are not ideal for SMB deployments using 4-bay towers or 6-bay appliances. It comes down to the budget, latency requirements, and the project(s) you’re running.

Examples of on-premises SAN appliances include StoneFly ISC and Voyager, NetApp SAN, Dell PowerVault, etc.

How Costly Are Traditional SAN Appliances?

The cost of an on-premises SAN appliance depends on the vendor you’re buying it from, the operating system you’re putting on it, and, of course, the hardware specs that you choose: processor, system memory, RAID controller, network ports, hard drives, etc.

Most vendors like Dell, HPE, or NetApp offer fixed models with little to no customization options. Consequently, you can find the price range on their websites or in their catalogs.

Other vendors offer you the ability to custom-build your SAN appliance and choose the specs as per your requirements. They build it, test it, configure it, and then ship the plug and play appliance to you. So, you can get the specs that you need in your budget range.

What Are Virtual SAN (vSAN) Appliances?

Briefly, virtual SAN (vSAN) are virtualized iSCSI volumes deployed on industry-standard hypervisors. I’ve written about vSAN in detail in the DATAVERSITY® blog post vSAN: Answering the What’s, How’s, and Why’s linked here.

vSAN trivia: “vSAN” is a term made popular by VMware. However, VMware vSAN is not the only vSAN solution in the market. Other examples of available vSAN appliances include NetApp vSAN, StoneFly vSAN, StarWind vSAN, StorMagic vSAN, and more.

Use Cases of Virtual SAN (vSAN) Appliances

In terms of use-cases, traditional SAN and vSAN appliances are the same. The only difference between the two is how they are set up.

In other words, vSAN appliances, like traditional SAN appliances, can also be used for structured workloads (examples listed above).

When to Use a Virtual SAN (vSAN) Appliance?

vSAN appliances offer a great deal of flexibility in how they can be deployed. You can deploy a vSAN appliance on a locally hosted hypervisor, cloud environment, or on an offsite server. This opens up a diverse range of applicability; however, flexible deployment also comes with its fair share of challenges like management, cost, availability, latency, etc.

When deployed on a local hyper-converged infrastructure (HCI), vSAN delivers scalable performance and great ROI, depending on the chosen vendor (VMware vSAN tends to be pretty expensive).

When deployed on public clouds or offsite servers, the latency comes into play. If it’s on a nearby region, then latency may not be a major issue — as evident from many companies running their workloads purely in the cloud. Alternatively, there are many enterprise customers that switched to the cloud and then turned back to on-premises.

Reasons vary on a case-by-case basis. So, if vSAN doesn’t work for others, it doesn’t mean it won’t work for you. Alternatively, if it works for someone else, it doesn’t mean it will work for you. So, again, your project, budget, and performance and latency requirements dictate whether a vSAN appliance is the right choice for you or not.

Cost of Virtual SAN (vSAN) Appliance

The cost of vSAN appliances vary depending on the chosen vendor, the deployment, and allocated resources such as processor, system memory, storage capacity, etc.

If vSAN is deployed in the cloud, then it also depends on the cloud cost, how often the vSAN is spun up, and how frequently it’s used.

Alternatively, if it’s deployed on a local HCI appliance, then the cost of the hardware and the hypervisor affect the ROI.

What’s the Difference Between Traditional SAN and Virtual SAN (vSAN)?

Besides the obvious difference that one is a physical appliance and the other a virtual counterpart, here are some key differences between the two:

Traditional SAN:

  • Requires external Network Attached Storage (NAS) or file storage volumes to allocate storage space for structured workloads
  • Migration, if necessary, tends to be fairly complex and error-prone
  • It’s fixed hardware. You cannot increase processing capabilities or system memory, but you can scale up storage by adding storage arrays
  • With an in-house SAN appliance, you don’t have to worry about egress costs, physical server security, or latency issues

Virtual SAN (vSAN):

  • Creates a pool of storage using available storage resources to allocate to virtual machines (VMs)
  • Migration, whenever necessary, is relatively easier
  • vSAN volumes are flexible. You can adjust allocated resources easily and add more processor, system memory, or storage
  • vSAN can be deployed in public clouds in a completely serverless setup

Which SAN Should You Choose?

There’s no universal answer to this question. For some projects or requirements, traditional SAN is the best choice, whereas, for others, vSAN is the way to go.

So, how can you determine which one is the best fit for you? A better understanding of your project, your performance requirements, and your budget are the first step. Additionally, getting proof of concept to try out can also be helpful.

Another way to make sure you make the right decision is to consult the experts. Get demos to understand the capabilities of the solution you’re looking into so that you understand the value you’re getting for your investment.


When looking into traditional SAN and virtual SAN (vSAN) appliances, it’s not about which one is the best. Rather, it’s about what your requirements are and which one suits you best.

Both solutions have pros and cons. Traditional SAN is well suited for large-scale deployments, whereas vSAN offers flexibility and more deployment options, making both suitable for a wide range of use-cases, businesses, and industries.

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