VMware vSAN enables organizations to set up an HCI-like environment in their data centers. Proper budgeting to set up a vSAN hyper-converged infrastructure environment includes balancing hardware cost against longevity and considering DIY options where possible.
HCI can pose an expensive investment question for many organizations. If your organization requires HCI capabilities, consider whether to buy an established HCI product from a vendor or whether your organization might be better off building a hyper-converged environment. If you elect to create an HCI-like environment yourself using vSAN and your hardware of choice, keep in mind that you might miss out on the tight integration of hardware through the specific software that makes true HCI what it is.
VMware's HCI capabilities
VMware vSAN enables an organization to use common storage to create an HCI-like environment. An organization can purchase vSAN independently and use it with any hardware, as long as that hardware is VMware-compatible.
The broad-scale VMware software stack -- including products such as vSphere, NSX and the vRealize suite -- already virtualizes compute and networking processes, but the addition of vSAN pulls these different products together under a single management plane and adds automation.
Hardware requirements for VMware HCI
Many HCI vendors have established support partnerships with specific hardware vendors, and most organizations prefer specific brands of hardware, as well. If you decide to DIY an HCI-like environment with vSAN, you can use nearly whatever hardware your organization likes. VMware supports a wide range of hardware, but not everything, so you must still check the compatibility list before installing vSAN. Important hardware for setting up HCI with vSAN include CPUs, network interface cards (NICs) and RAM sticks.
The latest generation of CPUs last the longest. Balance CPU speeds and cores against the requirements of your workloads -- too many CPU cores can have a real impact on your budget, because both Microsoft and VMware charge for additional licenses over a certain number of cores per CPU.
VSAN requires a 10 Gb network at a minimum. Consider using vSAN with a SmartNIC -- a SmartNIC can increase speeds by eliminating the shared storage vMotion tasks that are intrinsic to VMware's core software.
Apart from CPUs, RAM makes up the biggest expense inside the server. Most servers have a massive number of internal slots, so you can use smaller memory sticks to achieve desired memory quantities without breaking your HCI budget. However, if you fill up all of the slots and must expand, you might need to remove existing memory to add larger memory modules.
VSAN HCI on a budget requires you to comply with hardware compatibility lists for VMware.
To reduce costs, many businesses consider swapping out a solid-state drive (SSD) or non-volatile memory express for spinning disk drives. However, swapping SSD out for spinning disk might cost you more in the long run, because increased support and extended downtimes can affect your organization's bottom line.
If you must reduce your storage -- or other hardware costs -- consider delaying new hardware purchases and, instead, not fully populating your storage or memory. This leaves you the option to add additional storage or memory capacity without swapping your existing hardware.
Most HCI vendors build their offerings from common server platforms, which means an organization with a relatively tighter budget for HCI could save costs that typically emerge from overprovisioning and granular scaling by creating an HCI-like environment itself. However, in piecing together HCI, rather than purchasing a defined HCI product, you might not see all the typical features a vendor's HCI has to offer.
If you piece together HCI by hand, you might struggle to upgrade in the future. Vendors sell traditional HCI as a complete product, which can make it difficult to add one component at a time. Even if you have the correct hardware, achieving integration and compatibility between different components can take much more time and effort to achieve, compared to purchasing one vendor's holistic offering. A piecemeal approach to HCI can also present challenges for support, depending on the different pieces that make up your HCI.