As the world’s leading supplier of hard drives, Seagate knows well that all customers and storage applications are not alike. Sometimes the unique requirements of hard drive applications are intuitively obvious. For example, the storage needs of an enterprise database application are clearly different from those of a portable MP3 player stowed in a pocket while jogging.
Yet both systems use drives for storage and, though vastly different in size, they share a significant amount of technology in common. Other storage applications are much more subtle in their differences, while still having unique characteristics that must be acknowledged to ensure storage products deliver optimal value, performance and reliability.
Such subtle differences can be found in the growing hard drive market in the video surveillance industry. Here, drive use is expanding at a tremendous rate, reflecting the flexibility and advanced performance of hard drive storage over legacy tape-based systems. According to IHS, the estimated worldwide market for video surveillance equipment was worth over US$12.6 billion in 2012, and is expected to grow at a compound annual growth rate (CAGR) of 12.8% over the next five years to be worth US$23.2 billion in 2017. And in terms of revenue, the size of the network video surveillance equipment market is forecast to overtake the analogue video surveillance equipment market in 2014.1
While the adoption of hard drives over tape in video surveillance systems is reaching 100%, there is significant room for improvement in system interoperability, with reliability continuing to be an industry-wide challenge. Many customers, having moved to digital surveillance systems and drive-based storage, revel in the improved capacity, performance and flexibility but are disappointed by unexpectedly high failure rates. In addition, they hunger for increased performance to take advantage of the trends towards megapixel recording and intelligent video analytics.
Seagate has been working with customers who seek higher levels of performance and reliability, and has identified three key approaches to achieving that goal: ongoing education, improved practices in design, and deployment of purpose-built surveillance drives and related controls.
How much effect do environmental conditions have on a digital video surveillance system’s reliability?
For a specific example, the following graph displays the predicted annual failure rate (AFR) of Seagate® Surveillance HDDs as a function of case temperature and power-on hours (POH):
As shown, failure rates dramatically increase as drive case temperatures escalate. Dealers and system integrators, installers and even customers must be educated about proper operational conditions for video surveillance equipment if they are to mitigate damage to electronics and other equipment brought on by exposure to harsh conditions.
Where can I learn more about proper operational conditions for my digital surveillance equipment?
Seagate provides partners and customers with a range of educational tools that can be used to help inform people on drive opportunities, risk areas and best practices. Seagate maintains a library of technology papers that can aid in this educational effort.
Are there other factors beyond the operational environment that impact digital surveillance system reliability?
Proper enclosure or chassis design is a key factor in achieving optimal reliability. Electronic systems must be housed in well-designed enclosures specifically engineered for proper temperature management and vibration control or compensation. Because hard drives are critical components in digital surveillance systems, Seagate has developed its Customer Experience Engineering services, which provide dedicated engineering expertise to help customers evaluate system enclosures for best practices in temperature and vibration/shock management.
What is Seagate doing to help optimise hard drive reliability in digital surveillance systems?
The Seagate philosophy on improving products for a given storage segment is one of engagement. Intimate knowledge about the specific needs of a given storage segment is only achieved by actively engaging with customers and partners on a focused, low-level basis.
This philosophy is reflected in the Surveillance HDD, the industry’s leading drive specifically designed and optimised for the video surveillance market.
The Surveillance HDD represents a significant investment by Seagate in the engineering and support resources for a growing market. Such commitments result in valuable learning and advances in technology, functionality, performance and reliability that simply don’t occur as quickly without a focused approached.
How does the Surveillance HDD differ from other Seagate products?
IT component manufacturers design and market products by usage model or segment. Desktop, notebook, server and emerging consumer electronics have been the platforms manufacturers design around from processors to hard drives. But Seagate recognised that the surveillance DVR does not fit any of these platforms, forcing surveillance customers to choose the best-fit hard drive product for their solutions. Surveillance HDDs were specifically developed to address the needs of the surveillance DVR market. Below is a comparison of several Seagate drive products specialised to service different segment niches.
What surveillance-specific features should I look for?
With the Surveillance HDD, Seagate has focused on increased reliability and video streaming performance through power management and thermal control, and optimised data payload reading/writing.
While many surveillance digital video recorders (SDVRs) are implemented on a PC platform, most have moved to embedded systems that use optimised components. For example, it is common to use smaller, more efficient power supplies to save on system cost and control heat more effectively. The Surveillance HDD supports this design practice by offering best-in-class power consumption in both spin-up current and seek current. This approach doesn’t degrade performance, and it enables the use of low-cost, cooler-running power supplies and more efficient cooling fans, thereby lowering the overall cost of the SDVR while increasing the reliability and lifespan of the drive.
Are there other ways to cut my surveillance system’s heat output?
SDVR designs commonly include enough storage to hold a desired amount of online archival video storage. System archival needs can vary widely, from only a few days of archival video up to many months. Archival storage needs typically dictate using more than one drive in the SDVR system.
Of course, the most frequent function of an SDVR system is actively recording video. Once images are recorded on the system, they are rarely reviewed and sometimes never viewed again before being overwritten. To satisfy this use-model, most SDVR systems incorporate enough storage to meet the customer’s archival needs, and then record on the drives one after another, overwriting old data once the archival period has elapsed.
As a result, at any given time it is likely that one or more drives in the system are spinning and running at full performance levels, even though not actively being used by the system. The Surveillance HDD supports features that enable putting the drive into standby mode when not in active use. This greatly reduces the drive’s power consumption and heat generation, as well as extending its useful service life.
In addition, in order to satisfy the archival capacity requirements, some security professionals have chosen to utilise multiple moderate-capacity desktop drives in their video security systems. Their goal is to minimise storage costs; unfortunately, such efforts have met with little success.
Deploying limited-capacity desktop drives imposes significant limitations and liabilities on video security systems, negating any theoretical cost savings.
With no application-specific features to address power management, desktop drives can suffer heat-related failures caused by the rigorous duty-cycle and power-on requirements of video surveillance.
Also, more moderate-capacity desktop drives that are needed to meet a given capacity requirement unfortunately means more potential points of failure. The additional drives take up more space than necessary, consume more power and produce more heat—the latter a key factor in reduced drive longevity and thus surveillance system reliability.
Why is optimising read/write performance important?
Surveillance storage solutions must be designed with drive performance tuned for both video streaming and high-write workloads. Optimising performance for reading or writing video streams depends on reliable, predictable and timely command execution. Today’s surveillance systems commonly feature advances in intelligent video analytics and megapixel image recording. In order to manage the vast amounts of video and related metadata in an intelligent or megapixel surveillance solution, a keyed relational database or similar traditional data organisational system is often used. It is absolutely critical that reads and writes for such systems employ the utmost levels of performance and error detection and correction to ensure data integrity isn’t compromised.
An important feature of the Surveillance HDD is its support of the ATA-7 streaming command set. ATA-7 is an extension of the industry-standard ATA command set for controlling hard drives. The streaming component of this standard enables the SV35 Series drive’s reads and writes to be customised for either video or data payloads. Using the ATA-7 streaming commands, both of these requirements are elegantly met.2Additionally, the Surveillance HDD is optimised for write performance in both seek- and write-caching firmware. This is key for video surveillance storage workloads, where writing data can represent up to 95% of the hard drive’s operation. Favourable performance and drive longevity are highly dependent upon this enhanced write functionality.
Why is drive interface important? And why is the surveillance industry moving to SATA over traditional PATA?
Ballooning file sizes in video surveillance are behind the insatiable hunger for greater storage capacity; such data can quickly fill even the most copious storage system. But sheer drive capacity isn’t enough. Efficiently transferring these voluminous files demands drives with outstanding throughput, as well as robust error correction features to ensure data integrity is maintained during transmission. The SATA interface takes advantage of breakthroughs in very large scale integration (VLSI) technology and high-speed serial transceivers, enabling SATA drives to deliver an unprecedented blend of performance, flexibility, data integrity and reliability.
SATA storage devices have been embraced throughout the computing world, from OEMs to system builders/integrators and end users. Enormous sales volumes have helped drive down prices to very affordable levels. Couple this with the many compelling benefits of SATA and it’s easy to see why SATA hard disk drives have become the standard for most surveillance manufacturers, system builders/integrators and installers.
Surveillance HDD summary
The unique suite of features offered in the Surveillance HDD enables customers to immediately begin making incremental progress toward improved performance and reliability in video surveillance applications. The time-honoured Seagate strategy of focusing product categories on specific storage platforms to drive continuous improvement should pay still higher dividends in the future.
1 Source: IHS, The World Market for CCTV and Video Surveillance Equipment- 2013 Edition, May 2013.
2 For specific guidance and descriptions of how to implement the features of the Surveillance HDD, including the ATA-7 commands, see the Surveillance HDD Product Manual (formerly SV35 Series®).