A Comparison of the Best Hyper-Converged (HCI) Solutions

1. Support

2. Migration or Conversion process from existing solution

3. Cost 

4. Hardware compatibility 

5. Integration with all critical and non-critical solutions

6. Cloud readiness

Availability, support, cost, compatibility and scalability, cloud readiness.

> Integration with the existing running apps and solutions.

> Support Parameters.

> Ease of Scaling up and out the solution.

> Cost of the overall solution.

> Technical architecture of the solution.

> Integration with Cloud services/Solution should be cloud adaptive.

> Solution should be truly ready for the complete SDDC platform.

There are several solutions that claim to be HCI in the market, however the best factor is the native integration with the hypervisor without the need to have additional virtual machines that "perform HCI", so far in several cost-efficient scenarios that I have performed and in turn With different hardware manufacturers I can personally say that the best option is VMware vSAN. Its main strength is the correct management of hardware resources.

Collaboration

For me the most important component in an HCI Solution is the Software-defined Storage, so you always need to give great care when comparing SDS offerings from different HCI vendors.
You check the below points:
- Data Locality
- SDS Offerings (block storage, file storage, object storage)

Cost metrics, Rob, Capex, and open savings and even a TCO should be accounted for.

1) Operational efficiency assumptions based on assessments. This should yield time to deploy, VM to admin ratios, device consolidation, and power usage.
2) My most important thing is in the Recovery Time Objective and how well does it sustain without data loss. Recovery Point Objective measures how far you can go back without loss and RTO is how long mission critical devices are brought back online.

Since you will find yourself managing VMs, you might consider a cost analysis there as well. (Remember you won't be managing devices any longer)

Your benefits in using an HCI is
1) A VM Centric Approach
2) A software-defined datacenter- ( less replacement, better utilization, pay as you go)
3) Data Protection
4) Lower costs
5) Centralized and even automated self-management tools.

For me an HCI solution should provide me:
- ease of management, 1 console does all, no experts needed, cloud Experience but with on-premise guarantees
- invisible IT, don't care about the underlying hardware, 1 stack
- built-in intelligence based on AI for monitoring and configuration
- guaranteed performance for any workloads, also when failures occur
- data efficiency with always-on dedupe and compression
- data protection including backup and restore
- scalability, ease of adding resources independent of each other (scale up & out)
- a single line of support

While there is a long list features/functions that we can look at for HCI -> In my experience of creating HCI solutions and selling it to multiple customers, here are some of the key things I have experienced most customers boil it down to:

1) Shrink the data center:
This is one of the key "Customer Pitch" that all the big giants have for you, "We will help you reduce the carbon footprint with Hyperconverged Infrastructure". It will be good to understand how much reduction they are helping you with. Can 10 racks come down to two, less or more? With many reduction technologies included and Compute + Storage residing in those nodes, what I mentioned above is possible, especially if you are sitting on a legacy infrastructure.

2) Ease of running it:
The other point of running and buying HCI is "Set it and forget it". Not only should you look at how easy it is for you to set up and install the system, but how long does it take to provision new VMs/Storage, etc. It is great to probe your vendors around to find out what they do about QOS, centralized policy management, etc. Remember that most HCI companies portfolios differ at the software layer and some of the features I mentioned above are bundled in their code and work differently with different vendors.

3) Performance:
This could be an architecture level difference. In the race of shrinking the hardware footprint down, you could face performance glitch. Here is an example: When you switch on de-duplication and compression, how much effect does it have on the overall performance on CPU, and thereby affecting the VMs. Ask your vendors how they deal with it. I know some of them out there offload such operations to a separate accelerator card

4) Scaling up + Scaling out:
How easy it is to add nodes, both for compute and storage?
How long does it take while adding nodes and is there a disruption in service?
What technologies do the vendors use to create a multi-site cluster? Keep in mind if the cluster is created with remote sites too?
Can you add "Storage only" or "Compute only" nodes if needed?
All of the above have cost implications in a longer run

5) No finger pointing:
Remember point number two? Most of these HCI are based on "Other Vendors' hardware" wrapping it with their own HCI Software and making it behave in a specific way. If something goes wrong, is your vendor okay to take full accountability and not ask you to speak with a hardware vendor? It will be a good idea to look for a vendor with a bigger customer base (not just for HCI but compute and storage in general) - making them a single point of contact and more resources to help you with, in case anything goes wrong.

In my opinion, the most important criteria when assessing HCI solutions other than the obvious performance. How does that HCI solution scale? Or in other words, how does one add storage and compute resources to the solution. Without understanding how the solution scales one can easily request resources without understanding how and why the overall costs have ballooned. The costs can balloon not only because you're adding additional nodes to your HCI cluster for the additional storage and compute resources that were needed but also with additional compute nodes added to the cluster this requires additional licensing for whichever hypervisor the HCI solution depends upon. This is usually on a per-compute-node basis. For example, some HCI architecture allows admins to add only storage to the HCI cluster when additional storage is needed. Not requiring the purchase of any additional licensing from the hypervisor's perspective. On the other hand, some HCI architecture requires you to add a compute node with the additional storage you need. Even if you don't need the compute resources required to add that storage. That compute node will then need to be properly licensed as well. This type of architecture can and usually does force its consumers to spend more money than the circumstances initially dictated. So for me how the HCI solution scales is most important because it can ultimately determine how cost-effective the HCI solution really is.

1）Easy to operate or not

2）Cost

3）Scaleable 

Absolutely the important aspects are:

1- Simplification, simple to implement, simple to manage and simple to use.

2- Reliability; There is always more reliability compared with a traditional solution.

For these two items when you see the cost, or better compare the TCO to a hyper-converged solution is always better.

HCI solutions have matured over time. While the swing in the global market is a yoyo between VxRail and Nutanix, there are quiet a few new vendors who have brought Hardware Agnostic solutions to the market. Management, ease of implementation was the key yesterday. Of late, I see a plethora of customers, who needs multi-cloud connectors available. Nutanix has taken a decent lead here, with the acquisition of Calm. Pricey though, a minimum pack with yearly subscription provides for 25VM's. VxRail from Dell EMC has a lot to catch up there, however with a free API connector to AWS, free for the first three TB, and then priced per TB of movement between private and public cloud. DISA STIG compliance is yet another point customers are interested to see in the solutions. Nutanix claims their code is built to comply with these rigorous standards for secure Virtualization layer with AFS, whereas Dell EMC offers scripts that have been pretested, to ensure the environment can comply to the standards.

Backup companies are vying to get their products certified. Wonder what Nutanix would have for the currently certified solutions, post their acquisition of "Mine". It still has miles to go.

Data protection is my primary concern, backup restore is a must have feature.

Hyper-converged is typically an "all in one box/rack" solution. It consists of compute, storage & network resources all tied together physically (and through software). 

Hyper-converged for a pro - is a complete solution. You don't have to architect it. All you have to know is how much "power" you need (what you want to do with it). While with converged infrastructure (which can still be 'software defined') you have to match and configure the components to work together. 

More often then not converged infrastructure is cheaper. You might already have the storage and networking resources, for example. And manufacturers put a premium on packaging the solution together. 

Hyperconverged is a system cluster of at minimum 3 nodes. The system mirrors datas between nodes and runs virtual machines. 

Converged systems is anything between the classic server and hyperconverged platform. This converged concept was useful in waiting for hyperconverged development and should disappear in a near future.

converged infrastructure still incorporates hardware, running the technology natively on hardware. On the other hand, hype convergence is fully software-defined and completely integrated

Oh, you cant geht Tod of Hardware in and way.

But it is true That hci is a Software defined approach which has the advantage of delivering new features without new hardware.

Another thing that destinguishes hyperconerged Solutions from converged ones is the scale-out nature: simple add more nodes  to the system to support new workloads without losing  Performance because you add all types at once (compute, storage and networking).

Yes, you are right, as converged system is mainly hardware-based and HCI is a software solution.

However, Converged System is preconfigured, prevalidated and certified solution for each application. And is available from HPE, Cisco, and other vendors. Converged System is a combination of compute, storage, networking and hypervisor. Also, you have a choice of vendors in a configuration like servers you can buy from HPE, networking you can buy from Cisco, etc.

Whereas HCI is a software-based solution in which each vendor has different solution like HPE Simplivity, Nutanix or vSAN, etc. HCI is combination of 4 or more technologies/products, like compute, storage, hypervisor and networking, in one solution. The choice of a converged system or HCI depends upon the application and customer choice. As there are many pros and cons for both the solutions.

Converged Architecture is a cohesive combination of hardware (compute, network and storage) and software (virtualisation, bare-metal OS) that is managed centrally but typlically at the element level.  This is avavailble as a turn-key solution from a single vendor or as a refernence architecture where the Customer has a greater responsibity in defining what they want.

Hyper-converged architecture is still managed centrally but through the virtualisation element only.  Compute and storage elements are typically consolidated with multiple units becoming the platform.  This consolidation simplifies the design/deployment but expansion of one element usually means the other may also be unnecessaily expanded.

A newer architecture dHCI (disaggregated HCI) separates the compute and storage reducing the expansion issues of the original HCI systems.

Converged Architecture is more flexible and less system resources are used in system operation whereas HCI is simpler to operate.

Well 99% of those terms are marketing. Typically when a vendor asks - are you converged or do you have a hyper-converged infrastructure it is about hardware. But you have it backwards. Typically HCI is a "packaged" solution. It is the compute, storage & networking in one "box" (or rack or whatever). It is not only designed to work together, it's sold that way. 

Converged infrastructure is more do-it-yourself. You pick and design the compute, the storage and the networking to work together, sort of best breed for the money. I know at least in small scales - like for small-medium businesses - HCI is typically much more expensive. At least that has been my experience. I can put together a better solution for less money. 

Both of these terms are almost exclusively used in the virtual machine world, doesn't apply to "traditional" data center. 

The other term that you will see used with these two terms is software defined data center. That's marketing speak for when you use virtual networking and storage - for example in the VMworld virtual switches with vSphere and NSX. Storage can be virtualized with VMware's VSAN product or 3rd party products like StarWind VSAN (that's what I use). 

To put this all in perspective from my perspective: I have a 3-node cluster made up of (3) HPE DL-380's, with 60 disks spread across those (3) nodes being managed and presented to VMware through StarWind VSAN. Inside VMware I have virtual distributed switches & virtual networks setup. Physically there are several network cards in each server - teamed - and going to the appropriate physical switches on the physical segments of the network. According to what we've said above that would be a "software defined data center" running in a converged infrastructure. Again, most of this is marketing speak but it does help to define what's going on.

A Converged Infrastructure has more hardware.  Compute is on one set of hardware.  Storage is on another set of direct-attached (or other) hardware.  Networking is separated, too.

In a Hyper-Converged Infrastructure, Compute and Storage are on the same hardware, and depending on the complexity of the solution, sometimes Networking isn't even needed because you can directly connect the nodes to each other if you only have 2 nodes.  Adding nodes is as simple as duplicating the hardware and scaling up or out, accordingly.   

A Hyper-Converged Infrastructure requires less hardware and gives you a more simplified solution.  It is also less expensive to procure, operate and maintain.   

Also in a converged infrastructure software is important. Converged for me is a combination of hardware components that are sold as a single solution and where a software layer is added to make the management easier. But the hardware solution consists mostly from individual server, storage and networking components.
Most hyperconverged solutions goes further with integrating the storage layer into the server layer, removing a layer of hardware, and where the software inside the solution create a shared storage pool for the server stack. Automatically the management layer is also simplified just as with the converged solution... Less hardware (or differently used) and more software inside... I call it more a typical evolution of IT infrastructure... Know that converged and hyperconverged is a marketing thing and not really a product as such... I saw converged and hyperconverged solutions already 20 years ago before it even existed... Just look for what you need and pick the right solution... 

In principle you’re right “Converged Infrastructure relies on hardware, whereas Hyper-Converged Infrastructure is software-based”. But there are further advances for software management of containers, VMs, storage, and networks within a single architecture.

As a Red Hat partner, we are aware of coming developments based on Red Hat OpenShift which significantly simplify operations and provide complete management and portability across On-Prem, Hybrid, and Multi-Cloud environments.

The basic answers:

Converged is an infrastructure where you can configure all components like compute, storage boxes, load balancers connectivity glued by a software component that can show and admin al them as one.

Hyperconverged takes all those components and compresses all that functionality in just one box (server with storage and all software ) with software-defined infrastructure than can glue several of those all in one boxes to accomplish the scalability requirements. But remember HCI is not for all kinds of apps.

Whether to go 3 Tier (aka SAN) or HCI boils down to asking yourself what matters the most to you:

- Customization and tuning (SAN)
- Simplicity and ease of management (HCI)
- Single number to call support (HCI)
- Opex vs Capex
- Pay-as-you-grow (HCI)/scalability
- Budget cycles

If you are a company that only gets budget once every 4/5 years, and you can't get any capital expenditures for Storage/etc, pay-as-you-grow becomes less viable, and HCI is designed with that in mind. It doesn't rule out HCI, but it does reduce some of the value gained. Likewise, if you are on a budget cycle to replace storage and compute at different times, and have no means to repurpose them, HCI is a tougher sell to upper management. HCI requires you replace both at the same time, and sometimes budgets for capital don't work out.

There are also some workloads that will work better on a 3Tier solution vs HCI and vice versa. HCI works very well for anything but VMs with very large storage footprints. One of the key aspects of HCI performance is local reads and writes, a workload that is a single large VM will require essentially 2 full HCI nodes to run, and will require more storage than compute. Video workloads come to mind for this. Bodycams for police, surveillance cameras for businesses/schools, graphic editing. Those workloads can't reduce well, and are better suited for a SAN with very few features such as an HPE MSA.

HCI runs VDI exceptionally well, and nobody should ever do 3 Tier for VDI going forward. General server virtualization can realize the value of HCI, as it radically simplifies management.

3 Tier requires complex management and time, as you have to manage the storage, the storage fabric, and the hosts separately and with different toolsets. This also leads to support issues as you will frequently see the 3 vendor support teams blame each other. With HCI, you call a single number and they support everything. You can drastically reduce your opex with HCI by simplifiying support and management. If you're planning for growth up front, and cannot pay as you grow, 3 tier will probably be cheaper. HCI gives you the opportunity to not spend capital if you end up not meeting growth projections, and to grow past planned growth much easier as adding a node is much simpler than expanding storage/networking/compute independently.

In general, it's best to start with HCI and work to disqualify it rather than the other way around.

There are so many variables to consider.

First of all, have in mind that tendency is not the rule, your needs should be the base of decision, so you don't have to choose HCI because it's the new kid on the block.

To start, think with your pocket, SAN is high cost if you are starting the infrastructure; cables, switches, and HBAs are the components to add to this structure that have a higher cost than traditional LAN components, On the other side, SAN requires more experimented experts to manage the connections and issues, but SAN has particular benefits sharing storage and servers functions like you can have on same SAN disk and backup and use special backup software and functionalities to move data between different storage components without direct impact on servers traffic.

SAN has some details to consider on cables like distance and speed, its critical the quality or purity to get the distance; the more distance, the less speed supported and transceiver cost can be the worst nightmare. But SAN have capabilities to connect storage boxes to hundreds of miles between them, LAN cables of HCI have 100 mts limit unless you consider a WAN to connect everything or repeaters or cascaded switches adding some risk element to this scenario.

Think about required capacities, do you need TB or PB?, Some dozens of TB can be fine on HCI, But if there are PBs you think on SAN, what about availability?, several and common nodes doing replication around the world but fulfilling the rules of latency can be considered with HCI, but, if you need the highest availability, replicating and high amount of data choose a SAN.
Speed, if it is a pain in the neck, LAN for HCI starts minimum at 10 Gb and can rise up to 100 Gb if you have the money, SAN has available just up to 32 Gb and your storage controller must be the same speed, this can drive the cost to the sky.

Scalability, HCI can have dozens of nodes replicating and adding capacity, performance, and availability around the world. With SAN storage you can have a limited number of replications between storage boxes, depending on manufactures normally you can have almost 4 copies of the same volume distributed around the world and scalability goes up to controllers limits its a scale-up model. HCI is a scale-out model to grow.

Functionalities, SAN storage can manage by hardware things like deduplication, compression, multiple kinds of traffic like files, blocks or objects, , on HCI just blocks and need extra hardware to accelerate some process like dedupe.

HCI is a way to share storage on LAN and have dependencies like the hypervisor and software or hardware accelerators, SAN is the way to share storage to servers, it is like a VIP lounge, so there are exclusive server visitors to share the buffet and can share the performance of hundreds of hard drives to support the most critical response times.

Scalability and agility are the main consideration factor to decide between SAN and HCI. SAN infra needs huge work involvement when attaining the end of support, end of life situation. Also, budgeting and procurement frequency plays a role.

Also, the limitation of HCI to be single datastore in VMware environment is a problem, when disk corruption or data corruption happens.

There are multiple factors that you shall be looking at while selecting one over the other.
1. Price- Price for HCI is cheaper if you are refreshing your complete infrastructure stack (Compute/Storage/network) however, if you are just buying individual components in the infrastructure such as compute or storage only, then 3-Tier infrastructure is cheaper.
2. Scalability-HCI is highly and easily scalable.
3. Support- On a 3 tier architecture, you have multiple vendors/departments to call/contact to get support on the solution. Whereas for HCI, you call/contact a single vendor addressing all your issues on the solution.
4. Infrastructure- For very small infrastructure, a 3Tier architecture based on iSCSI SAN can be a little cheaper. However, for a medium or large infrastructure HCI comes cheaper every time.
5. Workload type- If you are using VDI, I strongly recommend to use HCI. Similarly, for a passive secondary site, 3-tier could be OK. Please run all bench-marking tools to know what are your requirements.

I am sure HCI can do everything though.

All depends of how you understand and use HCI:
If you see HCI as an integrated solution where storage is integrated into servers, and software-defined storage is used to create a shared pool of storage across compute nodes, performance will be the game changer of choosing for HCI or traditional SAN. The HCI solution of most vendors will be writing data 2 or 3 times for redundancy across compute nodes, and so where there is a performance impact on the applications due to the latency of the network between the nodes. Putting 25Gb networks, as some vendors recommend, is not always a solution since it is npt the bandwidth nut the latency of the network that defines the performance.

Low latency application requirements might push customers to traditional SAN in this case. If you use HCO for ease of management through a single pane of glass, I see many storage vendors delivering plugins to server and application software, eliminating the need of using the legacy SAN tools to create volumes and present them to the servers. Often it is possible to create a volume directly from within the hypervisor console and attach them to the hypervisor servers. So for this scenario, I don't see a reason choosing between the one or the other.

Today there is a vendor (HPE) that is combining traditional SAN in an HCI solution calling it dHCI. It gives you a HCI user experience, the independent scalability of storage and compute, and the low latency often required. After a time I expect other vendors will follow the same path delivering these kinds of solutions as well.

If things are working in a traditional way already and not much growth is expected then SAN is suitable. however, if things are on the cloud journey or already virtualized then HCI suites more.

There are two SAN (FC SAN and IP SAN), both use the SCSI v3 protocol:
- FC-SAN achieves a bandwidth of 16 and 32 Gbps.
- IP SAN achieves a bandwidth of 1, 10, and 25 Gbps.

SAN generally uses CI (Converged Infrastructure): “n” COMPUTE nodes, “n” NETWORK nodes, and “n” STORAGE nodes.

HCI (Hyper-Converged Infrastructure) uses only GbE network (1, 10, and 25 Gbps), through the SCSI V3 protocol. Each node is connected to an aggregate of nodes (Cluster – up to 64 Nodes) and have all 3 functions for each node (COMPUTE + NETWORK + STORAGE). These nodes are managed by a Hypervisor (VMware, Nutanix, ...).

If STORAGE capacity grows rapidly, HCI (Hyper-Converged Infrastructure) will not be the most suitable solution!

The two main problems are the NETWORK and the SCSI V3 protocol: high latency and limited by 25 Gbps!

The choice is more philosophical than deterministic, it depends on what you're going to do over this new infrastructure. All the answers are excellent and I have no all these aspects on my mind, but before choosing this or that what do you need SAN or HCI for? Who is going to implement and maintain the solution?