The IoT, mobility and cloud-based services have created a deluge of data that has pushed traditional storage approaches beyond their limit. IDC projects report that by 2020, the digital data universe will reach 44 zettabytes. So it’s not surprising that when VMware launched its virtual SAN in March 2014, companies looking for affordable, scalable storage solutions got excited. But almost three years into vSAN’s availability, how well does it measure up to expectations?
vSAN allows customers to use storage within ESXi servers without the need for external storage. Server admins were looking forward to using vSAN because it gave them a symmetrical architecture that did not require external storage, thus being able to use storage within existing servers. It also doesn’t require specialized storage skills. However, no one solution can be all things to all enterprises, and as enterprises began to deploy vSAN across their environments, they noticed something big was missing.
Creating a Win-Win Storage Solution
The drawback of vSAN, regardless of its benefits, is that it 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.
"vNAS enables the scalable, flexible solution enterprises are looking for "
Today’s large organizations also need support for hypervisors due to the rapid and widespread adoption of virtual environments. 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.
Since vNAS does not use an external storage system, 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.
vNAS enables the scalable, flexible solution enterprises are looking for. It does this by being software-defined, supporting both fast and energy-efficient hardware, having an architecture that allows users to start small and scale up, and supporting bare-metal as well as virtual environments.
The topic of protocols must not be overlooked here. 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.
Storage in the Cloud
The typical enterprise scenario is one in which there are multiple site offices. Each site has its own independent file system. It is probable that different offices have a need for both a private area and an area that 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.
Hybrid cloud is the most common storage configuration today for organizations; they are storing data both onsite and 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 that 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.
When a hybrid cloud architecture is based on vNAS, however, 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.
Configuring the file system in this way delivers the flexibility needed to scale the file system beyond the office walls—ensuring that 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.
An Elegant Pairing
The data deluge has been loosed from Pandora’s box and cannot be put back in, forcing enterprises to find an alternative to traditional vertical scaling solutions for storage. They need to transform their data centers in ways that provide storage that is efficient and less expensive – or risk being swallowed by the competition. This is the promise of vSAN, with its ease of set-up and speed. However, to achieve maximum effectiveness in enterprise environments, it needs support for file systems. vNAS provides that functionality, making for a next-generation pairing that creates a real storage solution.