The video surveillance industry has now on an era of network-based video surveillance and associated IT infrastructure. Recent days, with the number of higher megapixel cameras on the rise and longer retention requirements, users are struggling to deal with the data and cost requirements associated with storing this amount of footage.
In systems with long-term data retention, users can now use file-based tape storage such as LTO (Linear Tape Open) technology in combination with disk without compromising on the quality of the video stored or the length of time the video footage is retained.
Larger video surveillance storage requirements based on:
- Higher spec and resolution of cameras
- Large number of Video Surveillance cameras
- Increased value of data & longer retention times
Higher spec and resolution of cameras
The video surveillance camera is able to automatically adapt to environmental conditions and produce consistently usable images.
Higher Specifications: Image quality is complex with many different components can be measured through the camera’s specifications.
Specification of cameras: Resolution. Currently, the most common network camera shipping is 1080p resolution cameras. Four-megapixel cameras and with 4K resolution cameras for wide area surveillance even higher resolution cameras are available in the market. Equivalent 4K resolution video is four times the file size of 1080p.
Currently network surveillance cameras and 4K resolution or above are shipping across globally.
Large number of Video Surveillance Cameras
The number of video surveillance cameras has increased year on year. Video surveillance cameras, network surveillance cameras, HD CCTV surveillance cameras and body-worn cameras to law enforcement agencies.
Factors for the demand for cameras:
- Increased awareness of technology
- Multiple uses
- Price decreases
Increased Value of Data & Longer Retention Times
The majority of recorded video surveillance footage is never reviewed. But that detail as possible should be retained until it can be determined that which parts are relevant or valuable. However, the uncertainty of which parts of the recorded video is going to be useful means trade-offs between the quality at which video is stored and the length of time it is stored.
LTO Technology and Video Surveillance – LTO and LTFS
Linear tape open (LTO) technology is an open format of magnetic tape data storage jointly developed by HPE, IBM, and Quantum. In general, IT companies use LTO technology for data back-up, disaster recovery, and long-term data retention. It is used for making multiple copies of data and for cold storage offsite in vaults.
Since the release of the fifth generation, LTO technology has included the linear tape file system (LTFS) in 2010. LTFS utilizes partitioning to create an index which points to the requested file positions on the tape. This means that data can be dragged-and-dropped and viewed in a similar way to hard disk drives.
The LTFS format provides a self-describing cartridge which means applications do not require any additional information to read the data stored. In the event of a disaster where loss of data occurs, data can be recovered from tape. LTO-7 (6TB RAW and 15TB at 2.5:1 compression ratio) which can run 13 Days x10 1080p or 7 Days x5 4k streams stored per cartridge.
Recently released, LTO-8 (12.8TB RAW and 30TB at 2.5:1 compression ratio) which can run 29 Days x10 1080p or 14 Days x5 4k streams stored per cartridge.
In a tape library configuration used for long-term retention the time to locate and start reading data is slower than a disk array. However, this is to offer tape as a lower- cost, high-capacity alternative to hard disk drive arrays for longer-term retention. We know that Tape does not substitute disk as primary storage.
The LTO format has a technology roadmap with future specifications. What the LTO technology roadmap means in terms of video surveillance storage.
- LTO-9 (26TB RAW)
- 58 Days x10 1080p or 29 Days x5 4k streams stored per cartridge
- LTO-10 (48TB RAW)
- 107 Days x10 1080p or 54 Days x5 4k streams stored per cartridge
What can LTO Technology offer the Video Surveillance user?
When utilized in a multi-tiered storage solution, an LTO tape library can be implemented as a cost-effective, connected, long-term, high-capacity storage tier. End-users can manage their storage system. Also, remain within budget as tape can provide a larger capacity storage tier and longer-term retention for the same cost. This means end-users can compromise lesson video quality and retention time by using tape. Every detail can be stored until users can determine later what should be kept.
The utilization of tape to store video will not be best suited for all video surveillance applications. Multi-tiered storage works well with a high number of camera feeds which require extended storage retention at maximum quality. Data is transferred automatically between storage tiers based on pre-defined policies. The capacity of each tier and policy governing data transfer between them is typically based on the likelihood of requiring the highest performance.
For example, the most recent video may be kept on the highest performing disk tiers in the initial 7-14 days post-recording when access is most likely to be required. After this, it is moved to a tape tier (this point it is likely to be required for review).
However, the key point about this configuration is that data remains available through the VMS should review be required.
In addition, any video flagged up in a security or operational event of interest may have a different policy and may be retained for longer. Where events are required to be kept long-term or video evidence is used, a copy may be automatically transferred to a particular tier or even duplicated to offsite storage.
Using tape in a multi-tiered storage solution for long-term retention can mean that rather than pushing data to the cloud for storage, users can retain full ownership and access to their data for minimal cost.
Cloud storage can be used as an effective storage tier, particularly in collating data from small camera count multiple site installations, or as an offsite backup of a small amount of mission-critical camera feeds. However, as a storage tier for high capacities or long-term retention, there are additional costs to cloud storage which reduce its viability.
For example, high bandwidth costs, access and retrieval charges. Chain of custody is also a key concern for the use of secure data center.
Total cost of ownership (TCO) analysis should be used in conjunction with performance analysis to make a purchase decision for storage. A balance between cost and performance is necessary.
In many scenarios, the speed of data recall offered by a tape library is not sufficient and it should be reduced. Yet, for some users, if they can trade off immediate, for near-immediate access speeds to their oldest data, a tape can bring high capacity, long-term retention storage at price points they would otherwise have been unable to afford. Once the disk tier is configured further disk storage may only be required if additional bandwidth or camera streams are added. When only increasing the length of time data is retained building out capacity on tape can become even more economical as capacities scale.
In one example of a TCO analysis, when maintaining a storage system over a decade the comparison between a LTO tape library, an all-disk and a disk-cloud hybrid solutions found that the TCO for the LTO library solution was nearly seven times lower than the all disk solution and over five times lower than a disk-cloud hybrid solution.
As an approximate cost comparison of individual media, a recent LTO technology cost audit found an average retail price of $0.01/GB RAW, for an LTO 8 cartridge. The HDD market tracker estimates a typical enterprise grade HDD price at $0.06/GB.
LTFS and the batch pre-fetch plugins, available for many leading VMS solutions, enable end-users to simply go back in time further within their preferred video management application, gaining valuable insights which may otherwise have been lost due to compromises on stored video quality or retention times.