Can vNAS Take vSAN To The Next Level?

By Stefan Bernbo, founder and CEO, Compuverde

vSAN (a virtual storage area network) has been around for almost three years now. When VMware introduced it, the company gave the ranks of storage array and software vendors a run for their money in the race to win customers who were looking for scale-out virtual storage. Server admins were looking forward to using vSAN as it gave them a symmetrical architecture that did not require external storage, thus being able to use storage within existing servers. It also didn’t require specialized storage skills.

vSAN enables customers to use storage within ESXi servers without the need for external storage. The prospect of vSAN being able to deliver fast, resilient, scale-out storage was exciting. Now that the bloom is gone from the rose, so to speak, what do users think of vSAN today?              

vNAS: A Partner For vSAN

As enterprises began to deploy vSAN across their environments, they noticed something big was missing. Despite its many benefits, vSAN lacks support for a file system. The importance of having a file system within a data center cannot be overstated. Without a file system, the guest VMs cannot share files between them and are forced to use an external NAS solution as shared storage. Without a file system overlaying this data, it becomes impossible to scale efficiently.

Another fly in the ointment is the fact that, with the explosion of virtual environments across every industry, an enterprise setting requires support for hypervisors as well. Therefore, a scale-out vNAS needs to be able to run as a hyper-converged set-up. As a result, a software-defined infrastructure strategy makes sense here.

Because vNAS uses no external storage, it must be able to run as a virtual machine and make use of the hypervisor host’s physical resources. The guest virtual machine’s (VM) own images and data will be stored in the virtual file system that the vNAS provides. The guest VMs can use this file system to share files between them, making it perfect for VDI environments as well.

There are many qualities that align to make vNAS a flexible and scalable storage solution: it is software-defined, supports both fast and energy-efficient hardware, has an architecture that allows users to start small and scale up, and supports bare-metal as well as virtual environments.

Storage systems need to take protocols into account as well. vSAN uses a block protocol within the cluster, but when designing storage architecture, it is important to support many protocols. Why? In a virtual environment, there are many different applications running, having different protocol needs. By supporting many protocols, the architecture is kept flat with the ability to share data between applications that speak different protocols, to some extent.

A Flexible Hybrid Approach

Enterprises typically have more than one office site, and each site has its own independent file system. It is probable different offices have a need for both a private area and an area they share with other branches, so only parts of the file system will be shared with others. This common scenario, so essential to the functioning of a typical business, cannot be achieved with a vSAN.

The efficiency of the hybrid cloud has led more and more enterprises to adopt this method of storing data — some onsite and some in the cloud. Being able to use just the amount of cloud storage required, depending on the group’s needs, delivers excellent gains in performance and flexibility. The challenge is, in vSAN, there is no file system that can be extended to cover the data in the cloud and files cannot be shared between the onsite location and the cloud.

However, if vNAS serves as the basis of a hybrid cloud architecture, each site has its own independent file system. In a typical organization, different offices will need both a private area and an area that they share with other branches. As a result, only parts of the file system will be shared with others.

Allocating a part of a file system and letting others mount it at any given point in the other file systems delivers the flexibility needed to scale the file system beyond the office walls ensuring the synchronization is made at the file system level in order to have a consistent view of the file system across sites. Being able to specify different file encodings at different sites is useful, for example, if one site is used as a backup target.

Future-focused Storage

Data storage needs continue to increase as the world’s people and objects connect to the internet. Data centers are still primarily scaling vertically, but that is not a sustainable practice. Organizations need to scale quickly and inexpensively to stay in the game, and vSAN is a strong option. It is easy to set up and offers speed, but it lacks support for a file system. vNAS offers that support by creating a single file system that spans all servers, wherever they may reside.

Stefan Bernbo is the founder and CEO of Compuverde. For 20 years, Stefan has designed and built numerous enterprise-scale data storage solutions designed to be cost effective for storing huge data sets. From 2004 to 2010 Stefan worked within this field for Storegate, the wide-reaching Internet based storage solution for consumer and business markets, with the highest possible availability and scalability requirements. Previously, Stefan has worked with system and software architecture on several projects with Swedish giant Ericsson, the world-leading provider of telecommunications equipment and services to mobile and fixed network operators.