Proper storage of surveillance video is an important part of any security system, and the shift from analog video systems to digital IP cameras has only increased the potential for long-term, high-resolution video storage. But as camera resolutions increase into the multiple-megapixel range, (with 4k becoming a new standard in recording), so do storage needs and costs.
Finding the right video storage needs for your system, as well as how much you need, is about finding what works with your camera, recorder, physical space and budget.
How Much Video Storage Do You Actually Need?
Determining the right amount of storage for your CCTV system can seem difficult but is relatively straightforward. It’s simply a calculation of how long you wish to store surveillance footage, combined with your resolution and bit rate.
Storing 1080p footage from 12 cameras (an average number of cameras for most businesses) for 30 days, at the industry standard of 10 frames per second and encoded in H.264, would necessitate at least 8 terabytes of storage, for example.
Generally, it is recommended to store surveillance system footage for at least 30 days, providing a record of everything that happens for at least a month. But many large businesses and operations prefer to store it for up to 90 days – which necessitates a large amount of storage.
The downside to storing footage for such a long amount of time is the sheer amount of physical storage space and hard drives required. While 30 days of footage may only need about 8 terabytes, 90 days of footage at the same resolution, bitrate and frame rate would require over 24 terabytes of space. Bump the resolution up to 4k – as many cameras now record – and you’d be looking at over 133 terabytes of video – a massive amount of storage requiring large amounts of physical space.
While larger businesses and facilities with servers will likely be able to host such large amounts of footage, smaller businesses simply will not, necessitating a more moderate resolution and length-of-storage.
Storage Options For Surveillance Systems
Surveillance systems record footage with either a DVR or an NVR.
Traditional DVR’s are more common, functioning much like the DVR’s found in home entertainment systems. They have hard drives that can record video footage directly and easily. However, using a DVR limits the amount of footage one can realistically store, as they are not entirely scalable the way that other systems are. They also cannot be migrated to IP camera systems, which are becoming more and more popular.
DVR drive video storage is also very susceptible to hardware failure, as a single failed drive can cause the entire camera system to stop writing and storing properly.
NVR’s, on the other hand, work with IP network cameras and are scalable, allowing you to record and store far more footage than a regular DVR. They allow remote viewing, and can record input from cameras, video servers and other digital recorders. For these reasons, businesses and law enforcement departments are making the switch to NVR’s, allowing them much more scalability and storage options, as well as off-site monitoring and cloud recording.
Video surveillance footage is usually stored on traditional hard disk drives that have been designed and built for use with surveillance systems. CCTV drives need to be able to withstand constant use – 24 hours a day, 7 days a week – without failing. Regular hard disk drives, on the other hand, are not meant for such constant and heavy use and are more likely to fail.
Using an NVR also gives security systems the option of cloud recording, which helps eliminate the need for on-site storage, letting the service provider do the storage for you on their servers. The NVR will store video footage on an internal drive for a short amount of time, before uploading to the server. Many also have options to upload the footage at specified and scheduled times, to minimize bandwidth usage and stress on your network.
One potential drawback of cloud storage, however, is the cost associated with it. Most cloud storage providers charge a recurring fee for storage – a fee that can often be hefty. This cost must be compared with and balanced against the cost and physical requirements of physical storage on-site.
Tips To Decrease Video Storage Needs
There are a few ways to improve the efficiency of your video recording and record more – and more relevant – footage without necessarily adding more storage drives or being forced to scale down resolution.
One method would be to set cameras to record only when motion is detected; most video footage is never viewed, and removing potentially long periods of time where nothing is happening on the video feed can dramatically cut down on video storage required.
If possible, you can also set the system to record only during specified times of day, when surveillance needs are more paramount. You can also lower the frame rate, sacrificing smoothness for increased capacity.
Storing all your video surveillance footage easily and accessibly doesn’t have to be hard, and also doesn’t have to be prohibitively expensive.