On a Clear Path

Plan on significant storage capabilities to handle bandwidth

• By Tom Larson
• Nov 01, 2014

For those looking for a defined migration strategy to network video, the path can appear muddled. Today, there are countless manufacturers that claim to have a clear migration path toward an open architecture platform; however, there is simply no clear path that applies to all applications.

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.

Purpose-built, Video-optimized Servers

When designing or migrating toward a new IP-based physical security solution, it is imperative to use a server and storage solution that is purpose-built and optimized for video applications. A best-practice 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 resolutions and higher frame rates without dropping frames as well as cost-effectively store video data for longer periods of time.

In 2010, before the heavy influence of high-megapixel cameras, the introduction of 6G SAS drive technology into the video market offered significant system advantages over historical SATA drives. These bi-directional drives provide two redundant paths to every hard drive for increased availability and reliability in case of a single-path failure.

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 and a number of other issues.

Mission-critical IP video applications require greater protection than typical, off-the-shelf IT data servers, regardless of size and scope. Therefore, the importance of using 6G SAS drive technology in IP-based physical security solutions cannot be understated.

Types of Storage Technology

Storage of video in a typical network video solution can be an immense proposition. It could entail potentially hundreds of high-resolution cameras capturing as many as thirty frames-per-second, operating 24x7 for a month or up to a few years. The most common mistake made is to categorize streaming video as just another form of data. The case for purpose-built video storage over traditional data solutions focuses on five key areas: massive database size needs, I/O-intensive operations, intolerances of system latencies, constant bit-rate streaming and demanding operating environments, such as temperature, vibration and bit-error rate. 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. Three main storage technologies that are typically used in the IP video market include:

Internal storage. This technology records the video to the internal drives within the server. The logistics of having the drives inside the main CPU dictates no faster throughput for video data. These drives should be 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, in as little as 5U of rack space.

Using internal storage is the most popular, as it offers the best performance at the best price point. Video recorders should run in a single-application environment—that application being, recording the video. Today’s enterprise-grade IP video servers eliminate the expense and potential risk of running archive video over a virtualized solution in a shared environment.

Directed attached storage (DAS). This high-end technology 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 the internal storage. These drives should be protected by RAID 5 or 6, ensuring that if a drive was to fail that no data would be lost. DAS can be scaled up to 1680TB from a single server using as little as 22 rack spaces.

More importantly, properly-optimized DAS solutions can manage more than 1,000MBit/s of video ingestion. With the properly-built DAS, latency is reduced as data does not travel over large distances. Today’s DAS technology allows a security integrator to map cameras to one single drive partition instead of having to split the loads via a number of partitions.

Centralized storage (iSCSI). This technology is used when the end user would like to store video in a central location. iSCSI allows for multiple servers to send their video data across the network to a centralized storage array.

This storage technology, although popular in the IT world, is not as effective in the video world. This is due to other considerations that need to be addressed in order for the solution to properly work. The iSCSI storage device is only as fast as the network to which it is attached, regardless of SATA or 6G SAS drives installed. Once through the network, the 6G SAS drives will outperform the SATA drives, similar to within the internal server.

The storage array design must take into consideration the potentially large amount of data that could be streaming from multiple video servers. It is crucial that the storage array ingests the total bandwidth from all the servers simultaneously without bottlenecking.

The iSCSI storage solution can no longer be considered as a Just a Box of Disks (JBOD) device. More than ever, today’s video applications depend on these units having enterprise-server standards such as health monitoring, storage controller clustering, mirrored OS disks, redundant fans and power, and advanced memory protection.

Read the Fine Print: What is the Warranty?

Warranty seems to be a lot like an opinion, everyone seems to have one. Unfortunately, warranty needs to be based more on fact than opinion. It is important for the integrator to check those facts during the purchase decision. If the video recorder is down, the cameras aren’t recording. Suffice to say, the constant recording of the video is the key element of the project. Consider that the security integrator is generally on the hook for the three-tofive years of a security project, and yet, the warranty tends to get overlooked, until it is too late.

Determine the facts up front:

• Is the entire video recorder under one on-site agreement or are some or all internal parts—even critical parts such as the hard drives – not covered? If so, who is servicing those?
• Are they on a mail-in warranty or perhaps they are advance exchange?
• Are the replacement drives sent overnight, or do you pay the additional freight to get them the next day?
• When the drive does arrive, are you then the on-site tech or does the server company dispatch someone at their expense?
• What value do you put on your manpower if your company needs to go on-site and follow-up on a service call?
• Can you afford two service calls if you need to pull a drive today and then come back tomorrow or the next day to install the new one?
• What is the integrator and end-customer cost for processing an RMA versus a product that needs no RMA?
• What is the potential financial impact of the down customer as it relates to future opportunities or your company’s reputation? Did your upfront system savings become a distant memory? Have you subjected your customer to liabilities due to missing critical footage?

Seems the integrator has enough on their plate without having to walk through the warranty maze. As much as server manufacturers strive for the utopia of 100 percent up time, things happen that require immediacy and stability—without guesswork or added costs to their bottom line. Today’s enterprise-grade video recorders offer active health features which continually monitor the system status. Proactive alerts of potential failures will be sent before they occur. This allows the project server virtually zero down time throughout the length of the project and thereafter.

Regardless of the brand, the integrator should ensure the entire video recorder is covered by a full-system, on-site warranty, both inside and out. Otherwise, an integrator is buying five years of expense and risk.

This article originally appeared in the November 2014 issue of Security Today.