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Published on October 21st, 2014 | by Brian Suhr


Hyper-Converged Infrastructure comparison, Nutanix vs SimpliVity vs EVO:RAIL

With the hyper-converged (HC) market gaining momentum each of the last few years, there are more and more customers taking notice. The number of HC vendors and models is increasing quickly to satisfy different customer sizes and use cases. I saw a lot of confusion from people in the market on how these offerings compare to each other. So I thought a thorough comparison was needed. This would compliment the in depth reviews for each of these products as we are able to complete them.

Note: Additional details available for some cells by hovering over text.

I have been keeping this post updated since there are a lot of readers looking for data on SimpliVity vs Nutanix, Nutanix vs VSAN, Nutanix vs EVO:RAIL, and Nutanix vs SimpliVity.

Hardware Details

The early days of Hyper-Converged Infrastructure (HC) was our software on our hardware. It was the easiest way to create a predictable experience that the vendors could control. But as offerings mature and new vendors enter the market things are loosening up. We are seeing Nutanix and SimpliVity strike deals with major server vendors. While VMware created a product offering and is allowing hardware vendors to certify their hardware into the EVO:RAIL program.

As products mature and these new hardware options become available, I am seeing additional customers take interest. The questions of why did they build on that server product, with options from Dell, Cisco and others likely to come soon. Even the pickiest hardware snobs will soon likely be able to find a HC solution on a hardware platform that meets their standardized choice.

The discussion of scaling is both a hardware and platform discussion. I will cover it in the hardware section here. For scaling you need to consider both ends of the spectrum, what is the minimum number of nodes and is there a max number of nodes. This discussion will vary greatly based on customers and use cases. When considering an HC vendor for a customer, I would like to know would it be just be used in your data center, a ROBO option or both. This could sway my decision making a little in one direction possibly.

Don’t be fooled into some vendors having a limit versus others having no theoretical limit to the number of nodes in a storage cluster. In reality, your design will drive how many nodes you will require in a storage cluster and if you might need multiple storage clusters. You will need to consider if you need separation for workload types, for security reasons and also to control your failure domain size. An example would be if I built a 100 node storage cluster that could sustain two node failures vs building three separate storage clusters that can each sustain two node failures. The second option is likely to be more attractive to most since the failure domain is smaller.

If you are looking at the minimal size of the offerings, there are a few things to consider also. The different vendors have taken different approaches here. Both Nutanix and EVO:RAIL require a minimum number of nodes to build a storage cluster, ensuring availability. SimpliVity allows a different approach allowing single node install, that sacrifices local HA while benefiting from the global storage layer for backups and replication if desired.

As for scaling another important topic is how granular can I scale as the solution grows. Can nodes be added one at a time or is there a minimum number of nodes that must be added for each scaling event. Depending on your use this may or may not matter in the decision.


Hypervisor Details

When it comes to the hypervisor discussion with hyper-converged solutions, most tend to focus on two main points. First which hypervisor platforms do you support and secondly which versions are supported. These both carry different levels of importance to customers.

As the hypervisor space becomes more competitive and customers are implementing non VMware products to virtualize workloads,  the flexibility to support more than VMware is quickly becoming important. While VMware does still rule the world, there are certain verticals and customers that are adopting KVM or Hyper-V over VMware. Today this likely already plays into the buying decision for some customers when looking at hyper-converged products. Nutanix is already supporting multiple hypervisors, SimpliVity has discussed their desire to in the future, while VMware will always be a 100% vSphere based solution. Both of these stances can provide benefits for customers as they provide more flexibility or a tightly controlled integration.

As far as the versions of hypervisors they support is also a big factor in my eyes. There are a few things for customers to consider with versions. If you are new to a solution will they support the hypervisor version you are using currently, or will they force an upgrade or downgrade. This could be a big deal for some, you might have the option to use an older build to gain support for your version. But you then might be missing out on features that attracted you. Another thing to watch is how quickly do vendors update their software to support new hypervisor versions. I don’t think that people need day one support usually, but the question becomes how long will I have to wait. I think support within three months is very acceptable, if it typically runs longer than that it could be an issue for some.



Having a good management story helps put the hyper in hyper-converged infrastructure. Along with converging the storage and compute, I think that HC products should equally converge the management. In my eyes, this means a single interface for managing the product from a hardware, performance and upgrade perspective. After all these are products built from the ground up for one purpose and the management should reflect this.

There are different ways that these vendors built their interface. I have personal feelings about them, but will leave my feelings out of this one. You should look deeply at the different interfaces, find out what features they offer and the level of detail they make available to admins. There are three different approaches to the management of these products.

  • vCenter plug-in
  • vCenter web client plug-in
  • Separate web based portal

The management interface for these HC products all focus on managing on a per-VM basis. I think this is the right approach and while they are all taking different approaches, they all agree that the VM is what admins care about. Given this approach I expect to see all data on a per-VM view also. So details about performance, capacity, replication, backups and all other features should be present with VM granularity.

With these being modern storage, compute and virtualization platforms I come to expect extra from them. There should be some method of automating the product. These HC products make great platforms to build cloud solutions, VDI and server virtualization environments on. To aid in these the increasing demand for automation and orchestration should not be ignored on a modern product. How are the vendors providing you different methods for controlling and configuration. There are several options for this type of automation that I have listed below.

  • PowerShell
  • Python
  • Command Line



The connectivity into these hyper-converged products has been pretty stable. There are some increasing options as the products mature and new models continue to appear. The standard for the majority of models from these vendors is a pair of 10GbE connections. These two network connections provide the storage interconnectivity, VM traffic and sometimes management. Many of the models still also come with a pair of 1GbE connections and these are typically used for management traffic, but some offer the ability to use for storage or VM traffic depending on the size of the environment.


Storage Architecture

The storage part of this comparison is some of the most talked about details and often leads to FUD and fighting between the vendors over differences in features and approaches. I don’t intend on bringing peace to the storage industry but will try and explain the different offerings for easier consumption.

When it comes to storage the performance, availability and data services are some of the most important and most covered topics. This comparison is not going to cover performance, but I will be comparing the availability and data services that all three of the hyper-converged platforms offer.

A hot topic between the vendors is how they are enabling their HC storage layer. Both SimpliVity and Nutanix are using a Virtual Storage Appliance (VSA). There is a VSA on each node in the storage cluster and they act like scale out storage controllers. While VMware has taken the approach of building VSAN as a module in the vSphere kernel. Each approach has its benefits and draw backs. The VSA model will use more host resources to provide storage services. Using the VSA is allowing vendors to offer deduplication, compression, backup and replication among other services. While VMware’s integrated approach uses far less resources, it does lag in the data services it can offer currently.

The vendors are working hard on providing a highly available and resilient storage layer that can handle multiple failures. The very nature of hyper-converged is the blending of compute and storage, so to be able to architect for these failures you must ensure you have capacity available at all layers. Each vendor will offer guidance on how to architect to allow failure levels for the storage layer, ensuring you have the right capacity to allow for the number of copies of data. But do not forget about the compute discussion, while the storage might not be affected by dual node failure. Will you have enough compute resources available to handle a double failure? Will you even care about compute in a double failure as long as storage is still online and has no data loss?

The availability discussion is too complex of a topic for this level of comparison. But some important items to research and understand during different events are the following.

  • At what point could there be data loss
  • Will all or part of the VMs be unavailable during different failures


Install Details

To me one of the founding principals of hyper-converged infrastructure should be a simplified deployment process. This could mean a number of things to different people, I will layout my take on it. There are three areas of the install process that can be simplified.

  • Storage deployment
  • Hypervisor deployment
  • Hypervisor configuration

The storage deployment process is something that should be super easy and as automated as possible. This is the part that the vendors are creating and it should be an important part of their solution. By automated and simple, I would envision a process that deploys any VSA’s if there is one or enables the storage layer that is built-in. This would be accomplished from a management portal or deployment tool ideally. The process should allow the person deploying to enter in details such as network addresses and details, host names, NTP, service account and any other details. This information should be used by the automated install process.

To continue on with my idea, the deployment of the hypervisor should also be automated as part of the greater HC install process. The thought of having to mount an ISO and go through the hypervisor install seems old school and a waste of time. Its good to see this become more of a standard with offerings.

Last up is the post install configuration of the hypervisor. I think just installing the hypervisor is a bare minimum to be able to also install the virtual storage controller is not enough. The process should continue and configure a set of common best practices that apply to the majority of customer environments. This is a time savings benefit and also ensures that the product is deployed in an optimal manner. Today only VMware is taking it this far, I look forward to the other vendors maturing their process to include this phase.



While a simplified and automated install is important the fact is you only install a node once, but you will upgrade and patch it many times over the course of its lifetime. This is why the upgrade process and method can be a key differentiator in hyper-converged products.

Just like the install function, I think there are a few layers of the solution that companies can help customers with. While I think that having an easy polished upgrade for the storage layer is table stakes, any help vendors can provide for the other layers is added value today. But will likely become an expected set of features in the coming year. These are the layers that I think are targets for upgrade simplification.

  • Storage Layer
  • Hypervisor
  • Hardware Firmware

Hyper-converged solutions have been on the market for several years now, and I personally think that a storage software upgrade should be easy. It should be so easy a junior admin can do it and without any interruptions. This should not be a huge ask these days, pretty much every modern flash or hybrid storage array offers this same level of upgrade simplicity.

For the hypervisor layer, this is a nice to have feature at this time. We all know that upgrading hosts is not a glamorous job and no one likes to spend hours doing it. When upgrading the storage software in HC solutions, it may be also necessary to upgrade the hypervisor at some intervals. The market and time will determine how much of a differentiator this becomes.

The last layer is the firmware layer of a hyper-converged solution. This to me is the second most important of the three layers. Since all of the HC solutions have pretty tight control over the hardware that they are implemented on they should also be able to provide proper management of the firmware. They should be able to help with monitoring the firmware and provide better assistance with determining drive failures. Ideally the firmware upgrade should become wrapped into the solution in some method and hopefully vendors will start to recommend when upgrades should be performed when other layers in the stack are upgraded. This will help avoid performance or stability issues because a customer is running 2 year old firmware on the built-in network adapters for example.



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About the Author

Brian is a VMware Certified Design Expert (VCDX) and a Solutions Architect for a VMware partner. He is active in the VMware community and helps lead the Chicago VMUG group. Specializing in VDI and Cloud project designs. Awarded VMware vExpert status for 2011 to 2015.

49 Responses to Hyper-Converged Infrastructure comparison, Nutanix vs SimpliVity vs EVO:RAIL

  1. Miguel Balagot says:

    Well done. I was looking for this.

  2. akismet-658dded5f70e97dfeeddaaf6d80e9d9b says:

    Very valuable post! Great!

  3. Anonymous says:

    what about Nutanix Shadow Clones ?

  4. Laurens says:

    Thanks ! interesting comparison

  5. Great post, would have been nice to see a list price comparison also.

  6. Justin L says:

    Nice work. It’s been a little while since I’ve looked at this space, so this article was great to get start in getting up to speed again.

  7. gingerdazza says:

    What about the transferability of current Hypervisor licenses (in particular vmware)?

    • Brian Suhr says:

      This question will vary a bit between the choices. Lets start with EVO:RAIL first. Today all EVO:RAIL options include vSphere licensing as part of the sale, no option to reuse existing licenses. I think this is something VMware will eventually figure out and fix. Also the question is what happens when it’s time to refresh EVO:RAIL? Are they going to force you to purchase licensing again?

      For both Nutanix and Simplivity they are not selling you the VMware licensing. So you can purchase licensing in your normal manor if it’s a net new environment. If you have existing licensing and this gear is replacing it then you can reuse the licenses. Other than EVO:RAIL these options do not affect your VMware licensing choices.

      • DazzaBig says:

        One thing I am worried about with HC options/local storage aggregates is the latency of NR10. Having that second write needing to be ack’d over the network, and possibly to a lower tier, could affect write performance in multi mode configs. Seen reference to this in StoreVirtual VSA environments. With Nutanix, in a multi appliance cluster, does it use NR10? And how does mitigate this write penalty? I really like the concept of Nutanix thus far but wow it seems pric£y!

        • Brian Suhr says:


          Thanks for the comment. These modern HC products are far more advanced than the older traditional VSA products. I have tested all three of these with different workloads. I tend to focus on VDI and was able to do extensive testing with Nutanix and VDI which is a write heavy workload. The product functioned very impressive, with very low latency.

          I would suggest you look at the Nutanix Bible ( written by a long time Nutanix architect that is very smart. He explains a bit more about the data protection features in that section. The whole writeup covers the platform in great detail.

          As far as the price they are not cheap, but you are getting a high quality enterprise product. In my opinion you are paying for a performant, easy to use and simplified platform with great support. I explain to customers that it’s less about comparing X vs Y between two storage products. You purchase Nutanix because you are invested in changing the way you manage infrastructure.

          • gingerdazza says:

            For SMBs like ourselves I’d prefer smaller scale out chunks…. With evo:rail, StoreVirtual HC, and Nutanix isn’t it normally 4 host appliances at a time? For an SMB with current ‘traditional’ VMWare setups of 4-5 hosts, 150 VMs, and 10TB, this isn’t granular enough. We’d like single host scale out granularity – this is where the half-way house setup of pizza boxes with local VSA SDS can be of value. However, do Nutanix provide a platform design that might suit this scenario?….. It’s something that would appeal if they do.

          • Brian Suhr says:


            EVO:RAIL is only platform that forces you to scale at 4 nodes each time.

            Nutanix you always start with 3 nodes, and then you can scale by 1 node increments from there. You can also mix most node types so if you want different combinations of performance or storage capacity.

      • Brian Suhr says:

        Correct, I was glad to see VMware make this move recently. Having the flexibility around licensing will remove some frequent objections that customers have had to this point.

        • Tim says:

          I see the top problem with EVO:Rail in pricing. If you get a quote from HP or other Vendors it is highly above the “take your time for the HCL, generate a perfect fitted system for your needs, license vSAN and vSphere and everything else FOR YOUR NEEDS (for example: who really needs vSphere enterprise plus license?)”. Sometimes difference is up to 100k $. The said loyality program is a step in the right direction but it does not make it cheaper. I don’t have to pay twice for sure for licenses.

          • Brian Suhr says:

            I primarily work with enterprise customers and see 95% usage of enterprise plus licensing. The advanced features are used and worth it. EVO:RAIL is providing additional value over a build your own VSAN cluster and there has to be a cost for that. EVO has been more expensive than the other vendors, even with lower host resources. Not sure how much bring your own licenses will affect that. Pricing will work its self out over time as EVO partners and VMware learn from the marketplace.

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  10. Tim says:

    How does Nutanix archive metro cluster func.? Is it based on VMware’s FT (with all the exceptions) or is it an storage metro cluster and I have to reboot the VMs on Site-Failure?

    Thank you Brian!

    • Brian Suhr says:

      They accomplish it like all storage vendors, through the storage metro cluster. This offers synchronous storage replication between the two sites. If there is a site failure the VMs will HA restart at remaining site, same for all metro clusters.

      FT is a feature that only runs locally within a data center.

  11. Kevin says:

    For a SMB at what level of storage do the see simplivity bringing value to the table? Currently at 10 TB planning to grow to 18.

    • Brian Suhr says:


      Once you can deploy a couple of nodes you will see value from the start with any of these options. Management and operations is very simple compared to legacy options.

  12. Alfredo says:

    what mean TBD support ?

    • Brian Suhr says:

      Simply means that I was not able to get all of that data at the time of writing and updates. In the case of EVO:RAIL the support options may even vary between QEP vendors. I would recommend researching further if you are evaluating these options.

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  14. Brian Suhr says:


    As of October 12, 2015 I have taken a Tech marketing role with Nutanix. It is my intention to keep this comparison updated with the most recent publicly available data. I will continue to keep personal feelings and any slant out of the content.

    I will try to work with other HCI vendors to keep their data updated, as I think this is very helpful to the community. If you work for any of the other vendors in the comparison and notice something is outdated drop me a note and I will correct it.

    I know that my new role will cause some to feel that this is no longer a fair and impartial comparison, it should be clear that these are just data points and not an attack or statement of support for any product.

  15. Ramesh says:

    Simplivity has metro stretch cluster feature?

    • Brian Suhr says:

      Hello, They do not support vSphere Metro Storage Cluster (vMSC). They do not offer sync-replication between two clusters at different sites. Their current structure forces each unique vSphere cluster to go into a different logical vCenter data center so this would not work for stretching clusters in the same location either.

      • Piotr Skowronski says:

        Brian, as far as I understood SimpliVity guys you are more than welcome to build stretch cluster with OmniStack, but you have to keep on mind that it must not exceed c.a. 20-30km (just like with sync stg replication) because of possible latency. It is fully supported and gives you better resiliency with keepeng a copy of unique blocks of your VMs in other DC.

        • Brian Suhr says:

          Hello Piotr,

          The SimpliVity folks have a very different idea of what a stretched cluster is. They do not have a feature that can provide vSphere Metro Stretched Clusters (vMSC). You can verify from the VMware HCL at the link below. I’m not saying that you could not put nodes in different sites and try and make a cluster out of them, but it’s not an vMSC implementation and they are not engineered for these types or controlled or unplanned failovers.

  16. Night Owl says:

    Now that you are working for Nutanix, I think it would be fair to future readers of this article for you to note that fact, in BOLD, at the top of this article. While you may try to maintain this page as a personal effort, and attempt to be impartial, that is clearly impossible if your financial well being is tied to saying positive things about Nutanix.

    Since SImpliVIty OEMs servers from Dell, they would have exactly the same service offerings Nutanix would on thier Dell server. You don’t note that none of these options are available on their SuperMicro box.

    • Brian Suhr says:

      Hey Night Owl?
      I don’t hide where I work or have change the stance of this comparison. I don’t understand your OEM question if you can elaborate a bit more. SimpliVity does not offer a SuperMicro option or have any OEM’s. They offer a SVT branded deployments on Dell white box’d gear and have meet in the channel programs for Cisco and Lenovo. Don’t think other than how support is offered there is no difference in features.

      No features restrictions for Nutanix NX gear or any of our OEM partners. The OEM partners may ramp their models as Dell did and Lenovo will do now to have more options.

  17. Simplivity says:

    Great article Brian. I currently work for Simplivity and you almost nailed everything on the head. Even though our product is a Dell box. The Accelerator Card is 100% ours. That is the main selling point to our product compared to Nutanix or VxRail.

  18. Roman says:

    Hi Brian

    Thanks for this great comparison!
    Is EVO:Rail still alive? I noticed some vendors removed it from their website…

    • Brian Suhr says:

      Roman, EVO:Rail is dead but will receive patches and be supported for a few years probably. Most vendors removed it from their site, but if someone tried really hard you might be able to buy one from someone. :)

  19. Steve says:

    I looked at both the Nutanix and VxRail solutions. It was hard to pick between them. Eventually I choose Nutanix, and am very happy. The problem I had with Nutanix, is the storage nodes – they are pricey to scale for large Video deployments. Easy Solution – EMC Isilon.

  20. Richard Tull says:

    There’s a lot of inaccurate info here about Simplivity (and probably HyperFlex and VxRail as well, but I only know Simplivity), and you now work for Nutanix and are regularly updating this comparison but leave that detail buried in the comments. Not announcing that in bold at the top of your blog, and frankly maintaining this comparison at all while you work for one of the companies, is the very definition of intellectual dishonesty.

    • Brian Suhr says:

      Hello Richard,

      Actually, I don’t hide who I work for at all, fully disclosed on this page and on the About Me page etc as well as all social media locations. The tone of this honest review has not changed since the beginning and I try to timely update as these products release new versions.

      If there is something you feel is inaccurate send me a note with the details and documentation to back it up. I’ll review it and correct if the details are there.

      To this date this is still the most complete and honest comparison of leading HCI products available anyplace paid or free.

  21. Marvin says:

    It seems VDI is the best, maybe only candidate for HC platform. How about running SQL cluster on those?

    • Brian Suhr says:

      I think that statement would have been true 2 years ago. I would encourage you to talk with each vendor your considering and ask for references for any workloads you are interested in running. can only speak for Nutanix, but we see rarely any workloads today that cannot be run. This will vary based on different vendors and the maturity of their offerings.

  22. Jesan T says:

    Very nice post. Very useful

  23. Ron says:

    Brain thank you for the comparison, which you started before you sign-on with Nutanix, so I see that pretty accurate. I would love to see the updated versions comparied, since EVO-Rail is no longer being offered and now VMWare is come out with VXRail, which i believe is improved version of EVO-Rail. Also, Nutanix is now running newer version I believe 5.1 is the latest released version which has a few more features and improvement.

    Can you also elaborate the difference of using software RAID used by each vendor.

    Thank you again for a great comparision as I have read a lot about each of the HCI and your’s seem to be quite accurate.

    • admin says:

      Hello, I am long overdue for some updates. Will have to schedule some updates for these. Around the RAID differences question thats a pretty long discussion. Nutanix keeps 2-3 copies of the data with one being local to VM and others distributed in the cluster. VSAN/VxRail also uses replica’s but they are randomly placed in different diskgroups in the cluster, so FT1 would have a copy in 2 different diskgroups. SimpliVity uses a mix of old fashioned hardware RAID and RF2 which keeps two copies of the data. They mirror a VM between 2 nodes in the cluster.

  24. happy says:

    I love your writing. So well put, so complete. Keep up the good work.

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