E-Handbook: The advantages of SAN technology in an HCI world Article 4 of 4



Decide between SAN vs. hyper-converged for your virtual storage

Shared storage provides admins with virtual storage benefits such as storage migration, high availability and redundancy. But the right storage option depends on cost and performance.

There is a large array of virtual storage options available to IT administrators, and choosing the right option comes down to functionality vs. costs. Many admins rely on shared storage, a key component of most production-grade virtual environments.

Shared storage ensures that the elements that make virtualization a great tool -- such as storage migration, high availability and redundancy -- remain available. Shared storage comes in several formats, the two main varieties being classic storage area network (SAN) and hyper-converged storage.

Classic SAN provides admins with a dynamic and flexible storage option, while hyper-converged storage offers a simpler storage configuration. Oftentimes, deciding between SAN vs. hyper-converged storage comes down to questions about cost and performance.

Classic SAN storage for enterprise-level organization and SMBs

Classic SAN storage enables admins to divide storage into tiers within physical and virtual environments, and these arrays make this storage system highly dynamic and flexible. When admins think of SAN storage, they might focus on the vast storage arrays created by vendors such as Dell EMC and Hitachi. These storage arrays perform well but tend to come with high price tags.

A large SAN storage array might appeal to enterprise-level organizations. Larger storage arrays enable admins to provision several tiers of storage easily within the same physical system and often feature impressive expansion capabilities and redundancy.

Shared storage ensures that the elements that make virtualization a great tool -- such as storage migration, high availability and redundancy -- remain available.

However, for SMBs, these types of storage arrays remain prohibitively expensive. SMBs that want to maximize spend and feature sets while maintaining cost sensitivity can consider several inexpensive arrays, including as iXsystems' TrueNAS Flash-Powered Arrays that come with professional support.

Systems such as TrueNAS and other SMB-level storage products are extremely popular with several internet service and managed service providers, and companies seeking to modernize their storage at reasonable purchase and ongoing maintenance costs. In addition, new entrants into the storage market, such as Infinidat, continue to drive down array prices and make storage arrays more accessible to smaller companies.

Requirements for a storage array

Whether an organization is enterprise-level or an SMB, admins that adopt a classic SAN infrastructure must have additional infrastructure components that support it, such as fiber switches, cabling, maintenance staff and associated support contracts. Vendors such as Dell EMC, Hewlett Packard Enterprise and Lenovo now provide 10 GB -- or faster -- Ethernet to support SAN infrastructures, rather than the Classic Ethernet, which requires users to have a fiber-optic network. Classic SAN storage devices connected to a 10 GB Ethernet provide enough capacity for most admins, whether their organization is enterprise-level or smaller.

SMBs might experience lower SAN support costs compared to enterprise-level organizations because midmarket storage vendors can provide commodity switches for smaller storage environments.

Hyper-converged storage benefits

Hyper-converged storage relies on hyper-converged infrastructure (HCI) and does away with many of the complexities traditional storage infrastructure requires, such as cabling, redundancy and patch management. Essentially, hyper-converged storage shares storage resources across all the nodes in a virtual cluster and presents one or more logical units of storage to all the hosts within that cluster.

Top 5 hyper-converged infrastructure benefits

HCI provides the storage and network connectivity required for redundancy across all host nodes within a system. HCI providers also use 10 GB Ethernet, which helps further reduce storage complexity and the number of required cables.

Several vendors offer HCI products to admins, and hyper-converged storage tends to cost less than SAN storage. But hyper-converged storage can become expensive depending on required configurations and licensing. Adding storage to an HCI cluster means adding an additional node, which expands the cluster's storage and compute resources. The more nodes admins require, the more expensive hyper-converged storage becomes.

How to choose the right virtual storage

When choosing between classic SAN vs. hyper-converged storage, admins might prefer hyper-converged storage because it provides rapid implementation and expansion. Hyper-converged storage also provides redundancy, less physical hardware and lower costs than SAN storage.

However, hyper-converged storage is designed for a virtual environment, and admins using it can encounter problems sharing storage capacity within a physical environment. Some vendors enable admins to export Network File System and SMB shares, but others might not support a configuration that enables hyper-converged storage to serve storage resources to servers.

When admins determine whether to adopt classic SAN or hyper-converged storage, they must know how much data they have and how their systems use it. If admins have diverse, nonvirtualized systems, classic SAN might be the better choice.

Virtualized systems incorporate functionalities that enable admins to offload workloads to a storage system rather than the host, which boosts performance for certain data intensive, VM-centric operations. VMware and Microsoft have their own versions of this offload feature: VAMI and ODX, respectively. Depending on admins' hypervisor-licensing level, they might see a license uplift, although this doesn't apply to every storage array.

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