Video surveillance is big business – and while security surveillance systems garner a lot of interest due to their widespread use in helping prevent crime and catch criminals, there are numerous other applications, writes Nick Spittle, General Manager of Product Management, Toshiba Electronics Europe.
These include the monitoring of industrial processes where human observation could be potentially hazardous, the monitoring of traffic to help emergency services and alert transport safety officers to incidents as well as numerous applications in retail environments.
According to Transparency Market Research, the total video surveillance and video surveillance-as-a-service (VSaaS) market is expected to reach a value of $42 billion by 2019, with a compound average growth rate (CAGR) of 19.1 per cent from 2013 to 2019
With the growing popularity of video surveillance, there is also increased demand for storage devices. The surveillance industry continues to transition from analogue data capture and storage on VHS –style tape based systems, towards digital data capture and storage on HDD (hard disc drive)-based systems. With the introduction of IP-based video surveillance systems that generate high quality video storage demands have become more acute. Transparency Market Research predicts the total IP-based video surveillance market will grow rapidly between 2013 and 2019 with a CAGR of 24.2 per cent.
With historical surveillance footage becoming increasingly important to investigations into criminal, traffic and industrial incidents, data is being stored for longer and longer. In combination with the increasing quality of video being collected, storage of surveillance data is becoming a real challenge.
In a similar manner as the migration of general data storage to the cloud, VSaaS has started to emerge as an alternative to local storage and involves the management and archiving of video footage captured by IP-based surveillance cameras on cloud-based storage.
Figure 1 depicts the three main types of storage architectures currently in use, highlighting where the main storage systems (analogue audio video recorders (AVRs), digital video recorders (DVRs), network video recorders (NVRs) and IP-based storage area networks (SAN).
Figure 1. The evolution of storage architectures supporting surveillance systems
Technology
The HDD is the central component to the digital storage of surveillance equipment. The technology has evolved incrementally from the same basic concept that was introduced in 1956, with drives consisting of a stack of spinning magnetic platters that store the data and scanning heads that read and write the data. Innovations in speed, capacity and interfaces have dramatically reduced the cost per gigabyte and enable HDDs to handle large amounts of data very quickly.
One potential shortcoming of HDDs is the reliance on mechanical moving parts that come with some risk of failure. While solid state drives (SSDs) offer an appealing alternative in terms of speed, resilience and no-moving parts, they are more expensive than HDDs and not yet a viable alternative to systems generating large volumes of surveillance data.
To increase the throughput performance and reliability of HDD-based systems, multiple HDDs can be used in what is known as a RAID array (redundant array of independent discs). RAID provides redundancy by storing data on multiple drives, ensuring that any single drive failure does not stop the storage system working and that no data is lost.
There are various ways that RAID setups can work, with RAID levels 5 and 6 most commonly being used for surveillance systems as they provide a balance between data redundancy and total capacity needs.
However, RAID setups do have their own challenges, as having multiple HDDs spinning away storing data can be noisy, power hungry and vibrate a lot, which in turn can affect the efficiency of other HDD in the RAID.
Solving the challenges
As shown in Figure 1, the most suitable type of storage system depends on the number of cameras and the quality of the surveillance data recorded. For smaller surveillance systems using between one and four cameras, standard storage systems such as AVRs and lower-end NVRs are the most suitable type of storage available. For systems featuring between four and 32 cameras, NVRs and entry-level SAN systems are most applicable, whereas for systems featuring more than 32 cameras, large SAN systems come into play and here cloud-based, enterprise storage arrays are suitable.
The HDDs used in each of these systems need to be optimised for the specific application, however they all need to be high capacity drives, that are power efficient, not too noisy and are suitable for use in RAID / multi-HDD systems.
Within the last year, HDDs with capacities of 5GB have been launched, and customers now have the flexibility to retain higher resolution surveillance video data for longer periods using fewer HDDs, helping to maintain a smaller storage footprint and lower energy costs.
Designed specifically for mid-range systems featuring between four and 32 HDDs, Toshiba’s MD04 series drives can support up to 32 high definition cameras and provide 24/7 operation. The drives also incorporate rotational vibration (RV) sensors, making them suitable for use in RAID / multi-HDD based surveillance platforms.
When multiple HDDs are mounted in a common chassis, rotational vibrations caused by numerous HDDs spinning up and down has the potential to affect the positional performance of the actuators in the HDDs. Rotational vibration sensors provide a mechanism to sense these disturbances and provide a feedback mechanism so the actuator in the HDD to counteract the rotational vibration, maintaining and improving performance under these conditions.
Storage in the cloud
For cloud storage systems, high capacity and rotational vibration sensors are still critical. However, speed performance needs to be increased to cope with the added workloads caused by large numbers of cameras writing data simultaneously to a storage system.
In addition, in cloud systems high reliability is a key component so that less mirroring is needed and therefore total capacity and system footprint can be kept to a safe but effective minimum. To meet these needs, Toshiba has developed the MC04 series 7,200 RPM nearline HDDs that are available in capacities of up to 5TB and feature persistent write cache technology that protects the drives in the event of unexpected power loss. The drives provide a 25 per cent increase in maximum capacity and a 24 per cent increase in maximum data rate at outer diameter compared to previous-generation, drives.
Conclusion
With an ever-increasing number of surveillance cameras producing higher quality video, data storage needs are growing rapidly. Combined with the desire to keep data for longer periods of time and space constraints that dictate small system footprints, the need for high capacity HDDs is increasing at a phenomenal rate. Cost-effectively meeting the rigorous demands of surveillance systems that operate around the clock demands reliable high capacity HDDs that can ensure high performance while minimising power consumption and noise.
Whether in a local IP-based storage system, or in a remote cloud-based data centre, the market for high capacity HDDs for storing surveillance data will continue to grow, as will the need to develop drives specifically to meet the demands of surveillance systems.
Visit: www.storage.toshiba.eu.
Reference:
[1] Video Surveillance and VSaaS Market – Global Industry Analysis, Size, Share, Growth, Trends and Forecast, 2013 – 2019, Transparency Market Research, http://www.transparencymarketresearch.com/video-surveillance-vsaas-market.html
