The traditional\u00a0data center\u00a0is\u00a0built on a\u00a0three-tier infrastructure\u00a0with\u00a0discreet blocks of\u00a0compute,\u00a0storage and\u00a0network\u00a0resources\u00a0allocated\u00a0to support specific applications. In a\u00a0hyperconverged\u00a0infrastructure (HCI), the\u00a0three tiers\u00a0are combined into a single building block called a node.\u00a0Multiple nodes can be clustered together\u00a0to form a pool of resources that\u00a0can be\u00a0managed through a software layer.\n\nHyperconverged-infrastructure resources\n\n 8 reasons to consider HCI for your data center\n How to backup HCI\n Making the right choice: HCI hardware or software?\n HCI: It\u2019s not just for specific workloads anymore\n\n\nInstead of a server with 50 cores, 128GB RAM and 1TB of storage, you can have 500 cores with 1.2TB RAM and 10TB of storage across\u00a010\u00a0nodes,\u00a0presented as a pool of resources to mix and match into services\u00a0that deliver\u00a0the specific performance characteristics and back-end resources needed for the job at hand.\u00a0Configuration\u00a0can be done on the fly, through\u00a0an\u00a0easy-to-access interface\u00a0that lets you\u00a0build or scale your solution.\nThe result is that you get better utilization, which eliminates the need for overprovisioning\u00a0and enables\u00a0a better\u00a0total\u00a0cost of\u00a0ownership (TCO).\u00a0Compared to the\u00a0traditional three-tier architecture, HCI\u00a0also\u00a0is typically more compact and\u00a0consumes less power.\n\nRead more: How to choose the best NVMe storage array | SD-WAN buyers guide: Key questions to ask vendors (and yourself)\n\nPart of the appeal of HCI is that it combines storage, computing, and networking into a single system to reduce complexity\u00a0and streamline deployments\u00a0across\u00a0data centers, remote branches, and edge locations. But\u00a0be aware: A\u00a0bundled,\u00a0modular\u00a0approach\u00a0can provide simplicity at the expense of configurability.\u00a0It\u2019s important to consider issues such as compatibility with legacy infrastructure, scalability limitations and support for\u00a0cloud\u00a0tie-ins\u00a0when you\u2019re choosing a platform. This guide will help buyers of hyperconvergence\u00a0technology navigate the\u00a0decision\u00a0process\u00a0and provide key questions to ask potential vendors.\nHCI appliance or software?\nYour approach to\u00a0hyperconvergence will be tied to your existing investment as well as\u00a0your\u00a0future\u00a0plans. Are you buying all new equipment, or do you need to leverage existing infrastructure? Do you have special workload requirements to address?\nFor enterprises looking to invest in HCI, there are many questions that need to be answered either internally or in discussion with vendors or outside consultants.\u00a0Among the first\u00a0choices\u00a0to\u00a0make\u00a0is form factor:\u00a0Do you want\u00a0an HCI\u00a0appliance\u00a0or\u00a0a\u00a0hardware-agnostic\u00a0software-based solution?\nA\u00a0hyperconverged\u00a0appliance will provide preconfigured nodes of compute,\u00a0storage\u00a0and network\u00a0resources,\u00a0packaged in their own chassis. Some leading vendors that\u00a0sell HCI as an appliance\u00a0include\u00a0Cisco\u00a0(Hyperflex),\u00a0Dell EMC (VxRail),\u00a0HPE (SimpliVity), Scale Computing\u00a0(HC3), Pivot3\u00a0(Acuity), and NetApp\u00a0(NetApp HCI).\nEach HCI node includes compute, storage, and networking resources\u2014the bundled\u00a0nodes\u00a0are the\u00a0building blocks of the infrastructure.\u00a0Buyers can make\u00a0certain\u00a0configuration selections: You can purchase nodes configured with all high-performance SSDs, for example,\u00a0or\u00a0choose GPUs\u00a0to address specific workload\u00a0requirements.\u00a0Scaling capacity is\u00a0as\u00a0simple as adding additional nodes to the appliance.\u00a0Once part of the appliance, you can logically assemble systems for your specific performance characteristics through the\u00a0orchestration software layer.\nOne advantage of appliances is they let you to choose fully integrated and performance-tuned hardware right out of the box. Plug them in, turn them on and deploy as you need. For growth, you add more building blocks to the appliance to grow the pool. The appliance vendor\u00a0assumes\u00a0responsibility\u00a0for\u00a0making sure all software and firmware updates and patches have been tested and certified in advance of deployment, easing the burden of your staff having to track and test across multiple vendors. Downsides of this approach can\u00a0include vendor lock-in and difficulty integrating existing data-center components.\nIf you already have a\u00a0three-tier infrastructure that you want to continue to\u00a0use, you may want to consider a\u00a0software-based approach, available from vendors including Nutanix (AOS) and VMware (vSAN). This requires licensing a suite of applications that provide a hypervisor, storage-management, network-management and orchestration software to provision and manage your server, storage, and network components.\u00a0This approach\u00a0is hardware\u00a0agnostic; you can use any hardware\u00a0so long as it meets the\u00a0firmware revision\u00a0requirements of the HCI software suite\u00a0and is not so old that the software no longer supports it.\nA\u00a0software approach allows\u00a0you choose and maintain the hardware you want from the vendors you want,\u00a0creating a truly heterogenous environment. A downside is having multiple vendors to deal with for support,\u00a0which places\u00a0greater responsibility on your IT\u00a0 team to resolve integration problems, track bugs and\u00a0coordinate\u00a0patches.\nScalability of HCI\nThe building blocks of HCI are nodes of compute, storage, and network\u00a0capacity that use\u00a0virtualization for configuration and an orchestration layer\u00a0to\u00a0allow administrators\u00a0to\u00a0manage\u00a0them as a single pool of resources. It\u2019s important to understand the minimum requirements\u00a0and maximum size\u00a0of these building blocks\u00a0in order to\u00a0gauge\u00a0the cost of\u00a0future\u00a0growth.\nFor example,\u00a0HCI\u00a0typically\u00a0requires that to grow your storage pool, you need to add nodes with compute and network capabilities.\u00a0Some nodes are limited to\u00a0a specific type of storage\u2014HDD vs.\u00a0SSD,\u00a0for example. If you wanted\u00a0to add\u00a0network-attached\u00a0storage (NAS) or a storage area network (SAN), you\u00a0wouldn\u2019t\u00a0be able to manage them in the orchestration\u00a0layer and\u00a0would\u00a0have to connect them individually to the virtual servers you create.\nWhen thinking about scaling storage, you may not want to add additional CPUs and network ports. Some vendors\u00a0of either appliance or software-only solutions\u00a0support\u00a0disaggregated HCI, which\u00a0allows the addition of external storage devices such as a SAN into the mix so that you can grow your storage capacity separately from your compute. This is important if you anticipate\u00a0the two growing in\u00a0dramatically different proportions or have special performance characteristics you need to address (databases,\u00a0for example).\nAnother scalability issue is overhead.\u00a0The layers of software that abstract the hardware and allow HCI to work\u00a0need to be considered as you plan for capacity and expansion.\u00a0Ask your vendor how much overhead to account for.\nIn addition, make sure you\u2019re aware of\u00a0the upper capacity bounds of the orchestration software. Will you hit a point where you can no longer expand and be forced to create a new pool of infrastructure? Under those circumstances, you will be forced to manage\u00a0the\u00a0infrastructures separately and lose some of the benefits of hyperconvergence, such as data protection and live server migrations. Find out if you\u2019ll be able to move services between the two pools or\u00a0if\u00a0you\u2019ll\u00a0need to treat them like separate data centers.\u00a0\nFinally, what are the limitations of\u00a0your\u00a0license pool? How much can\u00a0you\u00a0grow\u00a0your\u00a0HCI before\u00a0you\u00a0need to go back and write the next check? Anticipating additional license costs and fully understanding what they are is critical to understanding TCO.\u00a0\nHCI orchestration and interoperability\u00a0\nAn important\u00a0consideration of HCI is whether\u00a0the\u00a0vendor\u2019s\u00a0orchestration layer can support the complexity\u00a0that comes along\u00a0with\u00a0disparately configured hardware.\u00a0\nAsk your vendors: Will\u00a0the orchestration software be able to mix building blocks of disparate sizes (for example, servers with different core counts and RAM capacity, different disk sizes, and types\u00a0of storage technologies)?\u00a0Or do all the building blocks have to be of the same configuration to be added to the HCI?\u00a0If you want to incorporate any legacy resources, will you need to upgrade (or downgrade) them before they can become part of your HCI pool?\u00a0It will\u00a0add to the bottom line if you need to buy additional RAM or storage for your current equipment.\nUnderstanding how the orchestration layer sees equipment can make a big difference when migrating\u00a0to\u00a0an\u00a0HCI.\u00a0Will\u00a0the\u00a0HCI be able to poll the network and easily incorporate\u00a0existing equipment\u00a0into the pool of resources?\u00a0It can be very labor intensive\u00a0if you\u00a0have to\u00a0move existing applications before you can add the applications\u2019 infrastructure\u00a0into the\u00a0HCI\u00a0pool.\u00a0Be prepared for\u00a0extensive and potentially disruptive work\u00a0if you need\u00a0to go through a process\u00a0of moving\u00a0existing services, then re-initializing and restructuring their underlying hardware\u00a0into building blocks before the HCI can use them.\u00a0\nVendor lock-in can also be a concern.\u00a0Does the solution allow\u00a0you\u00a0to add hardware components from any vendor? By abstracting the physical hardware and placing it into an HCI, you need to know if you can add any equipment, both legacy and new. This allows you to expand as you need to and avoid being locked into any specific vendor. Even if you choose to go the appliance route,\u00a0you may want to incorporate legacy systems that are acquired outside the\u00a0appliance. You\u00a0should know if you can continue to use equipment purchased from other vendors or if you are locked into a vendor\u2019s specific, proprietary solution.\u00a0\nWhat\u00a0hypervisor\u00a0platform will your HCI solution use?\u00a0Proprietary solutions\u00a0make it likely you will need to buy future building blocks from the same vendor. That could be desirable, as it\u00a0gives\u00a0you one source to contact\u00a0when you need support, but it also puts you at the mercy of that vendor for availability of equipment and software updates. Many vendors use a common platform, such as VMware or Nutanix AHV, but typically you can\u2019t mix and match in the same HCI, so an appliance with\u00a0a customized hypervisor can be an issue.\u00a0\nDo you have special peripheral requirements?\u00a0Are you dependent on GPUs,\u00a0special sensors, or\u00a0other types of hardware? Make sure you understand if you can build customized nodes and\u00a0if you\u2019ll be able to manage\u00a0any customizations\u00a0within the HCI or\u00a0if\u00a0you\u2019ll\u00a0need to build something outside the infrastructure to support them.\u00a0\n\nHyperconvergence features\u00a0to ask about\u00a0\nAs you\u2019re evaluating HCI platforms and weighing investment priorities, here are some areas to dig into.\nDoes the\u00a0HCI speak natively to public cloud services?\nIf\u00a0you\u00a0need to quickly expand services for a short business event (say you run an e-commerce site and need additional web servers for a special event), can you burst capacity into the cloud or will you need to overprovision within the HCI to support the business peaks? Will your orchestration layer be able to treat public cloud resources as if they are just another node in the HCI? Having seamless access to the cloud will allow you to quickly grow and shrink capacity without the costly and time consuming (and potentially disruptive) process of shutting down services and manually migrating them.\u00a0Some public cloud providers have worked to streamline integration between HCI platforms and the cloud.\u00a0\nWhat are the built-in redundancies and\u00a0disaster\u00a0recovery features?\nWill you need to provide additional building blocks and duplicate hardware for redundancy? Can you use cloud resources for this application? Will\u00a0your\u00a0data be automatically striped across multiple nodes, or do you need to add additional software to make that happen?\u00a0Integrating\u00a0an\u00a0HCI with a cloud service can provide a place for data to be stored safely off premises in the event of a disaster. Being able to replicate your services in the cloud, and then activate them in a disaster will dramatically reduce your\u00a0recovery\u00a0time\u00a0objectives (RTO).\nCan backup\u00a0appliances or SaaS work within your HCI?\nYou are probably already using some system to back up your data center. Will you be able to attach a tape robot to a node and have it visible through the orchestration layer so you can run a backup system to write to tape if you require?\u00a0\nWhat backup\/recovery support is built into your HCI environment if you want to use a SaaS-based product such as\u00a0Druva\u00a0or\u00a0Veeam? Can you attach a backup appliance from vendors such as Commvault, Rubrik or Cohesity?\u00a0This is becoming a more common feature, where the cloud backup is seen as another tier of storage in the HCI. The backup system runs as a virtual appliance on your HCI and speaks directly to the cloud.\u00a0\nWhat\u00a0additional storage features\u00a0are\u00a0built in to\u00a0the\u00a0HCI?\u00a0\nSome\u00a0HCI\u00a0platforms\u00a0provide tools that handle data deduplication to conserve storage space or encryption (in transit and at rest) as your data travels through the network for security and compliance. It may be that\u00a0separate tools\u00a0are required\u00a0to do work\u00a0such as periodic snapshots of\u00a0your\u00a0services for quick recovery in the event of a problem.\u00a0Make sure\u00a0it\u2019s\u00a0clear which features are standard and which require additional tools.\u00a0\nHow do you handle specific high-performance requirements?\nBare\u00a0metal is faster than HCI as it removes all the abstraction layers that add potential overhead to processor and storage access. But bare metal can\u2019t be supported in an HCI, since you can\u2019t control the hardware if it\u2019s not running the abstraction layer software. That\u2019s why it has been common to see large database servers with heavy performance requirements, for example, stay outside an HCI. Disaggregation is starting to solve some of these issues by allowing separate storage, such as a SAN, into your HCI, as well as enabling enterprises to incorporate special hardware building blocks, such as GPUs, to boost performance for specific applications.\nHow will product support work?\u00a0\nDo you call a single vendor for hardware support and a different vendor for hypervisor or orchestration support when you buy an appliance? Having support that can look at your problem holistically will bring faster resolution, and nothing is more frustrating than having multiple vendors pointing at each other to solve a problem.\u00a0\nZero-day\u00a0vulnerabilities are becoming commonplace, and they put the entire enterprise at risk. You should find out how your HCI vendors track for these problems and how quickly they provide tested updates to their customers.\u00a0\nCan you update the components of your HCI on separate schedules or do you have to update everything at the same time?\u00a0It can be advantageous to patch a portion of the infrastructure and test it for issues prior to performing a complete update.\u00a0Pushing massive updates across the entire infrastructure is sometimes necessary\u00a0and\u00a0often disruptive.\u00a0\nThere are many benefits to building an HCI environment. You will be able to quickly fulfill your server requirements using\u00a0familiar tools, reduce\u00a0the\u00a0time\u00a0it takes\u00a0to bring applications online, and ease\u00a0maintenance requirements.\u00a0But enabling\u00a0flexibility upfront shouldn\u2019t add complexity on the back end.\u00a0Make\u00a0sure the\u00a0hyperconverged\u00a0infrastructure you invest in will serve your application needs today and as you grow in the future.