It goes without saying that in surveillance, data integrity and loss time prevention are of utmost importance. Each individual unit that makes up a surveillance system – for example cameras and encoders – should ideally have built-in redundancy and resilience measures.
It goes without saying that in surveillance, especially that for highly critical applications, data integrity and loss time prevention are of utmost importance. According to a recent whitepaper by
Synectics, each individual unit that makes up a surveillance system – for example cameras and encoders – should ideally have built-in redundancy and resilience measures.
The paper started by saying ensuring data redundancy and system resilience has become critical in today’s surveillance, given the data generated by the system has become more valuable than ever. “In 2015 new surveillance systems generated over 566 petabytes of data globally. This data is no longer passive – generated and stored predominantly for post event review. It is active and in many cases proactive data and information that organizations need in real-time in order to make critical decisions that impact on security, safety, efficiency and in many cases profitability,” it said.
According to the paper, redundancy and system resilience can be adressed on two levels, through each individual unit and through the system. Unit-wise, each unit should ideally have some protective measures, and there are several technologies that can help in this regard.
RAID
According to the paper, there are seven main RAID levels but in practical terms, only three are used in relation to surveillance storage and data redundancy – RAID 1, RAID 5 and RAID 6. RAID 1 involves total data mirroring on two or more independent disks. In RAID 5, data is “striped” across at least three drives with distributed parity so that in the event of a single drive failure, all the data needed to prevent data loss can be calculated quickly from the remaining active disks. RAID 6 is sometimes referred to as “double parity RAID,” safeguarding stored data even in the event of two drive failures.
Hot standby power
According to the paper, hot standby power refers to a devices’ ability to draw power from an alternative source should the primary power supply fail, thus ensuring that data flow, storage and retrieval is unaffected. This has become an almost essential feature of surveillance solution components for mission-critical security and operational environments dealing with large volumes of data.
Localized storage
Another important redundancy mechanism for protecting IP video data in the event of network failure is localized storage, the paper noted. Increasingly, IP cameras and encoders are equipped with SD memory cards or internal hard drive storage. These can be configured to act as a data safety net should network interruption/failure occur.
Backfiling
When the fault or power failure is remedied and the network is restored, data may have become disjointed, split between edge devices and the primary storage server. According to the paper, surveillance management platforms equipped with backfilling capabilities avoid this scenario by being able to identify “missing” video once the network has been restored, identifying which devices have that footage stored, and automatically copying the relevant video back onto the primary storage server, all without any interruption to the management and operation of those devices.