Increasing retention requirements can drive the price of storage up as high as 30 percent of the total project cost. Due to the nature of security systems, reliability is of utmost importance. A hard drive failure can render the whole system useless if there is no place to store video footage or retrieve it. Systems integrators must therefore reach a practical balance between cost and reliability. a&s had a chance to sit down with C.N. Chu, Sales Engineer at
Seagate Technology, to discuss the future of storage for surveillance systems. “When I discuss how the future of surveillance landscape will look, I like to use the Jason Bourne movies as an example, if you want to understand contemporary surveillance, watch Jason Bourne,” said Chu. Even though in many aspects, the technology described in these movies is still science fiction, the presence of security systems and their impact on our every-day security and storage requirements is already here. “People now joke that it’s not easy to be a thief today. License plate recognition software (LPR) can track cars and their routes; facial recognition and analytics open up the possibility of tracking illegal activities, increasing the efficiency of police work. Analytics is becoming more sophisticated, computers need to run faster and the number of cameras are increasing exponentially. As a result, there is a need for more data storage capacity,” he added.
Surveillance versus PC hard drives
All the major vendors are rolling out dedicated surveillance drives which support surveillance DVRs (SDVRs), network video recorders (NVRs) and centralized or cloud surveillance for video data analytics. Chu pointed to several main reasons which justify having all these different products specifically for surveillance. “The hard drives used in surveillance differ from the hard drives used in regular PCs. PCs need to balance workloads, both reading and writing of data. However, in a surveillance system, the hard drive’s work load is 90 percent write and 10 percent read since the surveillance systems need to record all the time, while playback is sporadic. PC hard drives are not meant to run 24/7, they are not meant to be used in a multiple-drive environment where temperatures and vibration are concerns, and they are not tuned for multiple video streams at the same time,” said Chu.
“On the other hand, dedicated surveillance drives support three times the workload of standard desktop drives, are built to be NVR-ready (i.e., they can work with multiple hard drives), have lower power consumption to avoid overheating in a multiple-drive environment, and are ruggedized to perform reliably also in non-climate controlled environments,” explained Chu. “In our surveillance line we also added special firmware optimized to support up to 64 HD cameras without losing frames.”
An additional differentiator between a dedicated surveillance drive and a regular hard drive is the presence of a rotational vibration sensors. Hard drives which are designed to run continuously (24 hours a day, 365 days a year) generate extra heat and vibration compared to “regular” hard drives. When there are several drives packed together (like in an NVR), their vibration can disrupt the proper operation of the drive and lower performance. If there is any other source of vibration, like cooling fans, the performance deteriorates even further. Vibration can shake the drive head off its intended path causing data corruption or making the drive temporarily unavailable. The disrupted drive must then wait for its head to move back into position before resuming normal operation.
“One of the things we implemented to solve this problem is providing more rotational vibration sensors in all high capacity hard drives as we see surveillance systems take on more hard drives and vibration becomes a serious issue. For systems that have more than 16 hard drives, we recommend the use of enterprise-grade hard drives for better reliability,” said Chu. The rotational vibration sensors allow the drive to compensate and balance the drive when it senses vibration anomalies and can adjust the drive head as needed.
Future storage trend
Looking into the future, Chu sees growth potential in solutions for surveillance systems. “We see a growing interest in specific vertical surveillance projects that uses 2.5-inch drives. HDDs are a more viable option than SSD as HDD is more cost-effective and has a larger capacity, which are important when vast amounts of surveillance footage need to be stored for compliance and regulatory or data analytics purposes. We are continuing the development of larger capacity, more robust performance and NVR-ready features to offer customers the best way to manage their data and maximize the value of what they have.”