Caching Gateways are displacing the Enterprise NAS. Here’s why

Ask an enterprise IT admin about their file services. You’ll probably hear them say something about a bunch of file servers or network attached storage (NAS) devices. Those devices store the company’s unstructured data, including project folders and home folders. Enterprise NAS’s are expensive to own, a hassle to maintain. And these days, they’re stuffed to the brim with ever-increasing quantities of data.

The toughest challenge in delivering enterprise file services is without a doubt, how to protect the data. Backup solutions employed by most enterprises involve shipping incremental daily backups to off-site storage. This approach leads to recovery times and recovery point objectives measured in hours or days. Such numbers are unacceptable in modern enterprise standards.

A superior alternative is to continuously replicate the contents of a NAS into a secondary, offsite NAS. When combined with periodical snapshots, this strategy is more convenient than simply backing up files. It provides a warm standby NAS ready to go in case of failure.

The rise and impending fall of storage area networks

Storage area networks solved the storage problems of its time, but in the age of software-defined data centres and modern storage, architecture is it still needed?

But there are serious drawbacks to this approach. An obvious one is the cost. Organisations buying two NAS devices need to pay twice for their storage. They also need high capacity, redundant wide area links between the NAS devices. This type of solution is cost prohibitive for most organisations, especially for branch offices.

Enter the new kid on the block: that’s the caching gateway, also known as an edge filer. Edge filers provide file services by employing a fast, local storage tier such as HDD or SSD as a cache for a remote object storage system. The object storage is where the unstructured data of the enterprise lives, and much less expensively. Think of it as affordable housing for your data, costing typically 80% to 90% less than an enterprise NAS. Object storage can live in a public cloud (S3 coming to mind) or in a local datacentre. But object storage provides radically different semantics than a file system.

The magic of the caching gateway is how it provides seamless access to the contents of the object storage system using plain old file sharing protocols such as SMB or NFS. This means that employees and applications continue to access their mapped network drives, completely oblivious to the fact that they are interacting with an object storage service.

Designing for unanticipated storage requirements

How can you design today’s (and tomorrow’s) corporate IT infrastructures to cope with unanticipated storage requirements?

Caching gateways have many advantages. One obvious benefit is cost. Another is the elegance of this solution. If a gateway fails, install a new gateway, and all the corporate information comes back online in a matter of seconds. There would be no need for an initiated restore as all files are available. The caching gateway works continuously and in the background. While users access their files, they are populated on demand, fetched from object storage. This is a superior solution for disaster recovery as it is instantly providing access to information. You don’t need to back up or replicate a caching gateway, because it is a front for an object storage service that is redundant and replicated across sites.

But wait – things are becoming even more interesting. Imagine what happens if you connect not one, but multiple caching gateways in front of an object storage service. Get it? Now, a single global file system is accessible at many locations, with familiar NAS semantics – and at local speeds. Think about it. All your files, at the fingertips of any of your users, at any corporate location – with no perceptible latency, and at full local throughput. Users can move between the locations, while retaining full access to their files. And they can collaborate on files with people at any other location. That’s something that’s never been possible before, and it creates a whole lot of opportunities – limited only by your imagination.

To sum up, a caching gateway, also called an edge filer, has several advantages over an enterprise NAS. It offers instant disaster recovery without waiting for restore. It provides infinite elastic storage at way lower cost. But more fundamentally, an edge filer enables for the first time, a global file service. At last, users can roam and collaborate on files from any location, without being encumbered by such minor details as the speed of light.

Time for storage to come out of the back room

With overwhelming volumes of data, strict regulations coming in to play, and competitive benefits for clever data management, now is the time for organisations to sort out their storage. Here is some guidance for those still wondering how to tackle it

Written by Aron Brand, CTO of CTERA Networks

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