Storage development and common technologies: In the late 1990s, digital video processing (DSP)-based digital video surveillance began to become popular. Various codec technologies have been widely used in image processing. The processed images can also be digital code streams. The way to transmit, the storage of images also begins to enter the digital period. The most typical application is a digital hard disk recorder (DVR), which uses an internal hard disk for image storage.
This type of storage has fundamentally changed in terms of save time, image retrieval, system maintenance, and remote calls. However, since most of the digital video surveillance systems at this stage have obvious localization features and relatively small scale, the storage also exhibits obvious front-end and stand-alone features.
In recent years, with the rapid development of information network technology, networked video surveillance systems with centralized management and control through the central service platform and network video server and IPCamera as the front-end have begun to be widely deployed. Due to the reasonable architecture, flexible expansion and clear hierarchy, network video surveillance can bring users a new security application experience, which quickly becomes the main form of building a new generation video surveillance system.
The distributed front-end and platform architecture, centralized management and control, and flexible and convenient user access make the storage part of the network video surveillance system also begin to be networked. Networked storage brings a new storage architecture to video surveillance. On the one hand, users are more flexible in storage deployment and easier to access. On the other hand, it is more convenient to build a video surveillance system that requires large-capacity storage.
DVR storage: codec internal storage - DVR storage is currently the most common storage mode, the codec device directly mounts the hard disk, and currently can carry up to 8 hard disks. However, due to the limitation of the performance of the codec device, the hard disk sequential write mode is generally adopted, and the RAID redundancy technology is not applied to implement data protection. As the capacity of hard disks continues to increase, the probability of loss of critical data in a single hard disk drive increases synchronously, and the limitations of DVR performance also affect the sharing and analysis of image data.
The characteristics of this method are: cheap, easy to use, can be operated by remote control and keyboard; DVR mode is suitable for small-scale, distributed deployment. Domestic DVR products such as Haikang and Dahua's products are already very mature.
Codec storage: The codec plug-in storage device is connected through the external storage interface of the codec, and is mainly extended by storage protocols such as SATA, USB, iSCSI, and NAS.
This method can realize the re-expansion of the codec capacity, which is suitable for small and medium-sized deployment. The monitoring video data is guaranteed by the RAID technology in reliability. Among them, the SATA/USB mode adopts the direct connection mode, which cannot be shared and has low expansion capability; and the IP network (iSCSI and NAS) mode has better expansion capability and sharing capability. Haikang's DS series monitors NAS storage products, and Bunnon's SMI series storage products are well established in the monitoring industry.
Centralized storage: The server connects to the front-end codec, downloads data through the streaming protocol, and then stores it on the storage device. The server and storage device can be connected through SCSI, iSCSI, NAS, and FC protocols. Centralized storage is suitable for deployment of large and medium-sized platforms.
In the centralized storage mode, the IP connection mode (iSCSI, NAS) has good scalability and manageability, and has a high performance price ratio.
Data recovery: The monitoring device is often initialized after being connected to an ordinary computer, and can not be played again after accessing the monitoring machine. After a problem occurs, you can contact the Guangzhou Tuofei Data Recovery Center for video capture.
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