Hyper-Converged Infrastructure Constructs

Hyper-Converged Infrastructure combines Software Defined Compute, Storage and Networking to deliver a unified system for consumption. HCI Software runs on standard x86 Servers to abstract and pool the underlying resources which is dynamically allocated to VMs or containers based on Policies. Before getting into various platforms that are available for consumption today on HCI, Let us first understand the various constructs that build a Hyper-Converged Infrastructure platform so that comparison of platforms becomes much easier later.

• Workload Characterization – It all starts with the Use-Case. Understanding application requirement is core to identifying the right HCI platform and therefore its critical the overall requirement is gathered and evaluation carried out based on the requirement.
• Model – HCI is all about choice and flexibility. There are two models available for customers looking to invest in HCI – All FLASH & Hybrid ( Combination of SSD and HDD ). Depending on the Performance requirement and Storage Optimization needs, choice can be made between one of these Models.
• Hardware Choice – Considering HCI is about Software defined Storage & Compute (+ Network at times), You always have Choice of Hardware Platform for hosting HCI Software.
• Replication Factor – This is critical to determine the number of failure the solution can tolerate. Replication Factor is a policy for the number of duplicate copies of each data block that is written to HCI ( 2 or 3 Copies available )
• Licensing Model – This varies with every platform but at high level remember that this can be Software only licensing where we procure Software separately and install them on our own hardware or integrated platform like VxRAIL, Nutanix, Cisco Hyper-Flex where it can be based on combination and we will cover them in detail when we discuss on the platforms individually.
• Mode of Deployment – How are the nodes deployed at Customer Site? It can either be a Turnkey solution or Deployed On-Site solution (mostly when software and hardware are procured separately)
• HCI Models – There are two model (Edge vs Enterprise) depending on where you want to install and Scalability/Capabilities requirements.
• HCI Architecture – How is Hyper-Convergence Software deployed since it might vary depending on Hypervisor of Choice. It can be either In-Kernel or based on Control Virtual Machine ( The Software is deployed as a Service Virtual machines on the Hypervisor)
• Overheads – This is the resources that is needed for the HCI Software to perform. Depending on the HCI Software and deployment model (In-Kernel vs. CVM) overheads required would vary.
• HCI Supported Capabilities – HCI is just a starting point where in the resources are pooled and made available for consumption on a unified data platform. What additional capabilities can HCI deliver for consumption on top of the solution adds lot of value to customers. These may vary from File Services, Object Store, Analytical Services to Backup Services.
• Optimization – What are the Storage Efficiency capabilities that are available on the Platform – Efficiency (Deduplication & Compression) and Performance (Data Locality vs. Global Distribution )
• Scalability – Ease of Scalability of the platform (Scale-Up and Scale-Out). When demand increases one should be able to quickly add new nodes without impacting applications or Performance.
• Rack Awareness Capabilities – Rack awareness / Fault Domain capabilities are critical to building a resilient infrastructure along with increased uptime for the application and infrastructure. These are a set of capabilities where the HCI is aware of the node distribution among racks in a DC and ensures that duplicate copies of the data is always stored on different rack so as to ensure increased resiliency of the platform.
• Monitoring & Management – Support for Unified Monitoring and Management of multiple Hyper-Converged Infrastructure platforms.
• Upgrades – The simplicity and ease of upgrade of the entire platform right from the hardware to the software (HCI & Hypervisor) with minimal intervention from Administrator.
• Security – Security is a critical aspect with whatever do in a Datacenter and HCI is no different. Key use cases would be protecting data stored on HCI clusters which can be addressed in multiple ways starting from RBAC to Two factor Authentication to Data at rest encryption & locking down management access.
  
  These are some of the critical constructs for evaluating and designing right Hyper-Converged Infrastructure platform for your workloads.