When it comes to personal data storage, just when you think you’ve got more than enough, you run out of space. You could always use those ubiquitous USB thumb drives that you picked up at the last tradeshow, but even as a stopgap measure they’re pretty impractical. Just imagine the stress of pawing through a box of thumb drives to find the specific one containing the critical document or file you need at that very moment.
For heavy data users – music, photo, movie and gaming lovers – the consumer industry has introduced a slew of personal storage options to solve this problem, with inexpensive, high-capacity network attached storage (NAS) devices leading the way. But are these devices ready for physical security?
Three common storage options
Manufacturers offer a number efficient storage options for surveillance. One alternative is Direct-Attached Storage (DAS) where a subsystem of disk drives is directly attached to a server to expand its overall storage capacity. A Storage Area Network (SAN) is another option, but it’s usually considered an enterprise-level solution. Data storage on a SAN is typically divided between users and appears as just another drive on which to save information. Both DAS and SAN options are geared toward the corporate environment; but what if you are a small to medium-sized business (SMB)? In that case, NAS might be a more sensible approach to ad hoc file storage. It plugs directly into the network and it doesn’t require server hardware to run.
How does NAS play out in the physical security world? With more security applications moving to the IP backbone, NAS solutions are becoming commonplace tools for expanding storage. Network video cameras, for example, typically require larger amounts of storage because image quality is much higher than standard analog video. The increased storage demand and the cost of the cameras themselves generally limited their deployment to enterprise or high end installations. But with the cost of network cameras and NAS trending downwards at a dramatic pace, network video surveillance is becoming more affordable for SMBs to deploy. You can purchase a multi-terabyte NAS solution for less than $400. Combine decreasing costs with the ease of attaching these components to the existing network, small businesses can now install HDTV-quality cameras and archive video to a NAS at costs comparable to analog cameras attached to a DVR.
NAS as contingency storage
When integrators install a surveillance solution, they typically sized the video server from the outset to provide sufficient processing power and storage for the intended application. There are certain occasions, however, when a company might need to add cameras or increase recorded frame rates for a specific period of time that would impact server performance. In these situations, a NAS device could provide an easy and cost-effective solution for increasing the amount of storage needed.
NAS as local archive
Augmenting a hosted video solution is another niche role for NAS. Integrators are now offering Video-Surveillance-as-a-Service (VSaaS), charging a monthly fee to host a customer’s recordings offsite at a data facility. Using any device that supports a web browser, the customer accesses the video by logging into a secure website and viewing live or recorded images. This model – which is perfect for the multi-site business owner who needs a few cameras at each location – reduces upfront capital costs and gives the end user the flexibility of adding and removing cameras as needed without having to worry about sufficient onsite storage capacity.
A limiting factor for hosted video, however, is the amount of bandwidth available for video transmission. Bandwidth generally dictates configuration choices like resolution, frame rate and number of cameras that can be deployed. With a local NAS recording option, a user can archive video at a higher resolution and frame rate onsite while lower resolution, lower frame rate video streams to the hosting provider. If the customer sees an event that they want to examine in greater detail, they simply retrieve the higher quality video locally and review the incident. NAS devices can even be configured to regularly upload video to “the cloud” at times of the day when network traffic is low (after hours, for instance) so that it can take advantage of the open and faster pipeline.
This is a solution that dovetails nicely with hosted service providers that offer monitoring services to proactively mitigate risks as they occur. It’s similar to burglar alarm monitoring, except that the provider uses video as the main detection device. In this case, the monitoring company would notify the owner of the business that an alarm was triggered at the back door. The owner would log into the hosted solution, review video and determine if the person who set off the alarm was an employee or an intruder.
NAS as a server-less solution
A third video surveillance niche for NAS leverages the ability of network cameras to stream directly to the NAS device without the need for a server-based video management system (VMS). In its most basic form, the network cameras send video directly to a predetermined file structure on the NAS. From there, a user can view video from the cameras stored in the NAS folder. In this configuration, a small business could deploy a four camera system with a 2TB NAS solution for less than $1,500, delivering HDTV-quality video recordings. In its very basic form, this is a rudimentary solution offering no tools for searching the video or viewing multiple cameras simultaneously - capabilities that are found in even the most basic VMS. If additional functionality is needed, there are other client-based applications that provide a viewer “window” into the stored video on the NAS as well as live streaming from the cameras as a complete small system solution. Some of these applications are sold at app stores or are available free of charge from manufacturers’ websites.
So what are the issues with NAS? Until recently, NAS solutions were generally avoided because the technology wasn’t optimized for the write-intensive nature of video applications. As the use of network-based surveillance systems expanded, NAS manufacturers started developing products specifically designed for video solutions with disk drives that could handle the high I/O requirements and increased write speeds (see recent launches from Iomega and Netgear). But be sure when shopping for a NAS solution that the device you’re purchasing is especially built for the requirements of your system
Detractors of NAS storage solutions commonly cite concerns about NAS storage doubling the amount of bandwidth consumed when used in a traditional VMS model since the video is first streamed to the VMS server and then back to the NAS device. But proper bandwidth estimation and well-planned network design make this a moot point.
The need for cost-effective storage options will increase as more physical security products move to the IP backbone. NAS has been a staple in the IT and consumer industries with a decade of proven performance. As network drive capacities, write speeds and I/O performance continue to advance, NAS solutions will proliferate and become commonplace among security installations.
About the author: James Marcella has been a technologist in the security and IT industries for more than 18 years. He is currently the Director of Technical Services for Axis Communications.
