Cloud storage has the allure of being easy and cheap, at least in terms of zero capital investment. Yet more than a few companies are reluctant to consider using cloud storage in any capacity due to such bread-and-butter concerns as performance, availability, and security.
In this week's New Tech Forum, Ranajit Nevatia, vice president of marketing at Panzura, tackles each of these concerns head-on. His discussion focuses on the use of cloud storage controllers, detailing how they work at a low level and how they address issues related to cloud storage at the enterprise level. -- Paul Venezia
Surmounting barriers to cloud storage adoption
With a pay-as-you-grow economic model and unlimited scalability, cloud storage seems the ideal solution to the problem of heavy, ongoing investments in on-site data storage, particularly for multisite enterprises. These companies have either centralized file storage that must be accessed by remote offices over a WAN (with attendant latency issues and workflow disruptions), or they distribute storage among offices and must deal with file synchronization issues.
Cloud storage promises a way out of these problems, but many companies remain reluctant to move storage to the cloud. Let's take a look at how cloud storage controllers overcome common objections to storing data in the cloud.
The cloud storage disconnect
One problem with moving to the cloud is that enterprises store "files" and clouds store "objects" -- the latter being a new data construct required as part of the scalable cloud architecture.
Somehow, there must be a translation from file to object in order for enterprises to access cloud storage. Alternatively, customers can rewrite many of their applications to take advantage of cloud storage, but they're unwilling to do so because of the high cost. Cloud providers offer basic on-ramps to their clouds -- software that performs raw conversion from files to objects -- and these might serve the needs of small businesses, but they are not adequate for most use cases in a large corporation.
Other barriers to enterprise cloud storage adoption include availability, performance, and security. Companies are concerned that their users won't be able to access files in the cloud with the same speed as on-premises storage can deliver. Of course, there's always the worry that a network or cloud provider could experience outages, denying them access to data at a critical time. Companies are also reluctant to store proprietary data in a public cloud for fear of a hack or breach.
Cloud storage controllers provide a new way of addressing these issues. The controller automatically translates files to objects, eliminating the need to rewrite applications for the cloud. A cloud storage controller is deployed in each branch office and main office, and it implements a global file system that leverages Internet connectivity between sites to present a unified view of the file system to all clients, regardless of the local cloud storage controller to which they are connected. And a cloud storage controller provides unbreakable security. Let's look at how cloud storage controllers solve the issues of availability and security.
Availability: The cloud file system
The key feature of a cloud controller is its file system. A main principle behind the cloud controller's file system is the physical and logical separation between payload data and metadata. In a traditional file system, a snapshot contains both payload data and metadata, and it's managed as a single, large chunk of information. With a cloud controller file system, metadata can be easily extracted from a snapshot and transported separately from the payload data while maintaining file system consistency. When clients interact with a file system, the bulk of their actions are actually metadata operations that do not require access to the payload data.
Navigating through directory structures, opening folders, looking through file lists, and sorting/searching for files based on attributes such as file name, file size, file type, date created, and date modified are all metadata operations. The user experience is greatly impacted by how quickly metadata operations occur, so most file systems cache metadata in RAM to speed response times. Thus, a core design principle in a cloud controller file system is to preserve the response time for metadata operations in a global deployment.