Understanding the VMware vSAN Value Proposition
VMware vSAN™ is a software-defined storage solution for VMware vSphere® environments. vSAN clusters employ the local servers HDDs and SSDs to create radically simple, high-performance, resilient, shared storage, designed for virtual machines and now with vSphere 6.5, offer block storage to external systems via the iSCSI storage protocol. Some of the key benefits of vSAN for service providers are:
• Lower TCO: Reduce TCO by up to 50 percent by leveraging server-side HDDs and SSDs to create a converged and resilient shared storage solution within the hypervisor.
• Lower CapEx: Server-side enterprise storage economics lowers capital expenses over array-based solutions.
• Lower OpEx: Automation, power and cooling, $/TB, labor costs. With vSphere integration, current vSphere and storage skillsets can be used to manage the technology. In other words, “if you know vSphere, and a bit about storage, then you know vSAN.” In addition, management that is more efficient lowers operating expenses, which has the potential for significant overall OpEx savings.
• Predictability: No large upfront investments. vSAN allows you to scale granularly, and avoid overprovisioning and overpaying for future capacity and performance needs.
In addition to the above, vSAN is simple and automates time-consuming manual storage tasks. Not only is vSAN managed through the vSphere Web Client, but it also integrates with other VMware products, such as VMware vCloud Director® and VMware vRealize® Automation™. This integration into VMware's Cloud Management Platform solutions further simplifies the provisioning and management of storage in service provider data centers.
The cold hard truth is that storage infrastructure for service providers has become exceedingly complex, and often the “ad-hoc” solutions that are employed in order to try to achieve a Cloud delivery model have only added additional complexity. The fact is, most service provider problems can be traced back to poor infrastructure design choices, and rather than fix the root cause, service providers’ operational teams spend the vast majority of their time trying to remediate the environment. This leads to increased operational overhead through perpetual troubleshooting and recurring optimization activities. Therefore, the simplification offered through vSAN and a move towards a Hyper-Converged Infrastructure (HCI) offers service providers a break from their longstanding frustration with the complexity and high cost of existing storage systems, making them, in most cases, highly receptive to VMware’s vSAN “best of breed” storage offering.
In this vCAT-SP paper, we aim to address how the vSAN product affects operations and therefore operational costs. vSAN brings both a software-defined storage infrastructure and a VM-centric storage model together into a single solution, which can significantly reduce the TCO of storage, when compared to a traditional SAN and array architecture.
The vSAN hyper-converged storage model offers a software-defined storage approach that alters the acquisition cost of storage and fundamentally alters the ongoing operational costs in a number of different ways, including, but not limited to, the following:
Acquisition Costs (CapEx)
• Avoids proprietary storage hardware lock-in and associated costs
• No dedicated storage adapters (Fibre Channel HBAs) in hosts
• No requirement for fabric hardware, such as Fibre Channel director or Top of Rack switches
• Based on server-side economics − server components (hardware) competitively priced versus traditional external arrays (hardware + software)
• Lower upfront costs with granular scaling
• Leverage falling storage costs year-on-year by:
o Spreading your purchases to benefit from declining prices
o Growing storage alongside compute (creating a building block architecture)
o Taking advantage of new hardware technologies coming to market
o Benefit from higher resource utilization through:
Eliminating overprovisioning of resources and SLAs
Avoiding low utilization due to LUN-VM mismatches
Simpler budgeting, forecasting, and capacity planning
Operational Costs (OpEx)
• Merge vSphere and storage administrative roles and operational costs
• Daily task efficiency through higher admin productivity and simple automation
• Deployment simplification and reduced footprint
• Simpler budgeting
• Lower the cost of specialized operational skillsets (labor costs)
• Simpler automation
• Power and cooling
As a result of this significant change in CapEx and OpEx models, the typical pattern of hardware acquisition seen in service providers using the vSAN model can be contrasted with the traditional model, as shown in Figure 3:
Figure 3. Traditional Upfront Storage Provisioning Versus a Linear Scale-Out Model
Source: Sample pricing based on vendors/resellers public website prices
As seen in Figure 3, another significant contributor to the lower TCO of a VMware vSAN solution is the lower cost of entry for hyper-converged server hardware, with no requirement for two or more dedicated storage fabrics in the architecture. Not only is the initial CapEx investment lower, because vSAN Ready Nodes or appliances typically cost much less than traditional storage. You can also scale them incrementally, by adding smaller numbers of HCI nodes or even by just adding storage capacity through additional disk groups, when required. This model of scaling an infrastructure compares very favorably with buying larger bundles of disk trays, disks, compute-only hosts, and fabric components separately.
Furthermore, if there is space available in the rack, you can simply configure a new vSAN HCI node into an existing cluster, and in a matter of minutes be ready to scale the storage and compute infrastructure. This building block approach saves a significant amount of time, versus racking and cabling new array disk trays, configuring new host servers, cabling the new Fibre Channel HBAs across multiple isolated fabrics, configuring new fabric zones on Fibre Channel switches, and so forth.
Though vSAN delivers a compelling story for both CapEx and OpEx, this white paper focuses on how software-defined storage can transform the long-term OpEx costs for service providers. I examine vSAN product operational management, and drill down into the detail of a number of key operational tasks associated with service provider storage provisioning and management and the associated vSphere infrastructure. We also address the key data points in a comparative examination, which aims to estimate the overall time and effort required for common OpEx tasks on VMware vSAN, when compared with traditional array and fabric SAN-based storage systems.
