Video Storage Solutions
Servers, storage and workstation technologies are key components of an IP-based physical security solution; however, many organizations are still trying to leverage existing analog-based assets to meet their video surveillance needs. Even though those analog solutions might pass for minimally sufficient, the data-intensive nature of today’s network video technology makes this approach problematic. An integrated and holistic approach to building an IP-based video surveillance solution is what the market needs.
Although well-intended, manufacturers’ minimum specifications as a one-size-fits-all solution seem to create systems that struggle to address customers’ application requirements for both video surveillance and other business security functions. Forecasts suggest that nearly half of all video security systems will run off network cameras by 2015. Non-standard systems will begin to underperform as systems attempt to scale as megapixel cameras are added to the environment.
The migration to IP-based physical security and the shift from VGA resolution to megapixel and high-definition resolutions has placed a burden on network bandwidth and has created several system management challenges. Compared to standard resolution cameras, bandwidth needs from high-resolution cameras can increase tenfold. Consequently, the input/output (I/O) capabilities of IP video servers need to be significantly greater, and in many cases, standard data servers, even powerful enterprise servers, are not built to withstand the rigors and nuances of IP video feeds.
Greater emphasis is now placed on incorporating integrated server, storage and workstation solutions that can handle the immense increase in bandwidth and processing demands. New technologies such as edge storage are inherently integrative, which fills the gap of out-of-network mobile applications or network failures. In some instances, companies are leveraging third-party data centers to host cloud-based video; however, this is still an emerging technology.
The Benefits of Integration
From the shift to open and redundant architecture hardware, to the emphasis on total cost of ownership and return on investment, market trends all point to a more integrated IP-based physical security vision. A truly integrated IP-based physical security solution can also take advantage of today’s best technology, such as higher camera counts, resolutions, access control integration, more intuitive and powerful user interfaces, and multiple analytics.
Of course, as with any complex technology, there are significant challenges that can be a hindrance to a clear migration path. Interoperability limitations also present obstacles, with end-users concerned about being too dependent on any single manufacturer, managing the multiple communication protocols and dependence on support, especially for highly sophisticated IP-based physical security solutions.
Even though organizations such as ONVIF are working toward industry standards, the lack of interoperability in many video system products is a serious concern for planners and integrators. This is especially true when it comes to mission-critical functions. Supporting high-resolution cameras from multiple manufactures requires significant storage and server capabilities to handle the increased bandwidth.
Handling Storage Issues
When designing or migrating to an IP-based solution, it is imperative to use a server and storage solution that is purpose-built and optimized for video applications. A video server demands mission-critical quality drives with high I/O capabilities and unconstrained workload capacity.
Server configuration is vital and should include memory, storage and processor specifications that ensure optimum scalability for video. Video servers should have the capacity to accommodate future growth, including the ability to record higher frame rates without dropping frames, higher resolutions and cost-effectively store video data for longer periods of time.
The 2010 introduction of 6G SAS drive technology into the video market has demonstrated significant system advantages over historical SATA drives, including dual port, full duplex, concurrent active channels, robust command queuing and superior error detection and correction. Dual port is important because it provides two redundant paths to every hard drive for increased availability and reliability in case of a single-path failure.
The importance of using 6G SAS drive technology in IP-based physical security solutions cannot be understated. The high I/O workload of network cameras can constantly inundate servers, as client workstations on the other end simultaneously attempt to pull video for review. Both slower speed and SATA drives can cause significant bandwidth issues directly due to the buffering that is required with single-channel data transfer. This lag can result in dropped or frozen frames, video artifacting — which is distortions and other visual inconsistencies resulting from compressing a video feed — and a number of other issues. Mission-critical IP video applications require much greater protection than typical off-the-shelf IT data servers, regardless of size and scope.
The Case for Purpose-Built Storage
Storage of your video in a typical network video solution can be immense. It could entail potentially hundreds of high-resolution cameras capturing as many as 30 frames per second, operating 24x7 for a month or up to a few years.
The most common mistake made is to look at streaming video as just another form of data. The case for purpose-built video storage over traditional data solutions focuses on five key areas:
1.Massive database size needs;
2.I/O-intensive operations;
3.Intolerances of system latencies;
4.Constant bit-rate streaming; and
5.Demanding operating environments, such as temperature, vibration, bit-error rate and more.
Because of the intrinsic nature of streaming video, each of these five areas requires a purpose-built approach that takes into account unique needs, capabilities and system demands.
Here are four storage technologies that can be used for IP video retention:
Internal Storage is the most popular and offers the best performance at the best price point. The technology records the video to the internal drives within the server. The drives are protected by RAID 5 or 6 ensuring that if a drive was to fail, no data would be lost. Today’s scalable servers can house up to 240TB, all internal to the server.
Directed Attached Storage (DAS) is used when there is not enough drive space available within the server chassis. Because of its multi-lane SAS connection to the server, DAS performs almost identically to internal storage — the drives are also protected by RAID 5 or 6. Direct Attached Storage can be scaled up to 1120TB from a single server using just 22 rack spaces.
Centralized Storage (iSCSI) is used when your customer wants to store the video in a central location. It allows for multiple servers to send video data across the network to a centralized storage array. While popular in the IT world, this storage technology is not as effective in the video world. The iSCSI storage device is only as fast as the network to which it is attached, regardless of what kind or how many SATA or 6G SAS drives are installed. The storage array design must take into consideration potentially large amount of data — it is crucial that it ingests the total bandwidth from all the servers simultaneously without bottlenecking the storage array.
Edge Storage, or on-board storage, stores audio and video recordings within cameras, typically with an SD card. It is particularly beneficial for mobile security or applications that experience network connection interruptions. Edge storage is an excellent complimentary enhancement to central storage that facilitates comprehensive and seamless video coverage building additional redundancy in the solution.
The Missing Link: Video Optimized Workstations
One often overlooked piece is the client viewing station. The highly demanding needs of video surveillance requires a workstation built for 24/7 performance; however, many times an existing workstation or standard PC specification meant for employees is used as the client viewing station.
Purpose-built workstations for video feature higher level cooling systems, 450 watt and greater power supplies, dual Ethernet adapters (for management), server-grade processors and expanded display capabilities.
The primary demands on client viewing stations are compression and process-intensive decoding in order to properly render video. As compression algorithms continue to evolve, the demand on workstation performance will only grow exponentially. Keeping that in mind, video processing workstations should be as future-proof as possible, with the ability to expand and scale up to support future compression algorithms.
At the end of the day, the client viewing station is a key component of the customer experience and should not be cut short, as this only serves to reduce the quality and effectiveness of the entire network video solution.
Tom Larson is Director of Global Accounts for BCDVideo. To request more information about the company, please visit www.securityinfowatch.com/10455642.
