Ⅰ. Bandwidth and storage computing
Bandwidth and storage are very important in video surveillance projects. The following points should be considered when designing bandwidth usage and storage size:
1. Number of cameras
2. Video recording method. Motion detection video or 24 hours of uninterrupted video recording.
3. Front-end SD/TF card edge storage, or back-end NVR/storage server storage, or a combination of both.
4. Camera frame rate
5. Camera image resolution
6. Video encoding method
Camera installation scene: static indoor environment, multi-motion outdoor scene.
Ⅱ. Common storage methods
SD/TF card storage: Front-end camera Micro SD/SDHC/SDXC card storage, It generally supports a maximum of 128GB currently.
FTP storage: The camera or NVR supports the FTP service, which can directly upload the pictures and videos captured by the alarm to the FTP server.
NVR storage: NVR connected to hard disks for direct storage.
NAS storage: The camera or NVR supports network hard disk storage, which can be directly mounted to network hard disks.
VMS storage: VMS storage software runs on the server and connects to storage devices through SAS, iSCSI, NAS, FC and other protocols.
Cloud storage: It supports public cloud storage (cloud server), or object storage method (such as network disk).
Ⅲ. Storage type
1. Edge Storage
Edge storage saves video recordings in the SD/TF card of the front-end camera, or in a NAS server or a file server.
Edge storage can provide more flexible video storage methods. It can improve system reliability, ensure video recording quality on low-bandwidth networks, facilitate remote and mobile monitoring and integrate with video management software.
Edge storage can complement centralized storage and it can record video on a local SD card or NAS. When the remote storage system is unavailable due to network or remote storage server failure, the video is stored on the SD card. When the network or remote storage server recovers, the video in the SD card is automatically sent back to the remote storage server, which ensures the remote integrity of the video files in the storage server.
At the same time, when the network bandwidth conditions are not good, you can choose to store the mainstream locally to ensure the storage of high-quality video files. The remote access to the substream is better suited to low bandwidth conditions.
In addition, edge storage can be used in environments without a network. The video is stored on the SD card. When there is a network, the video data is automatically uploaded to the back-end management storage center.
2. Server-based storage
PC computer + management software storage. You can run the video surveillance management software on the PC and use the hard disk of the PC as the storage space for video surveillance.
3. NAS/SAN storage
Local storage is not suitable if the data storage capacity is too large. You can use NAS or SAN storage to expand storage capacity and increase storage reliability and flexibility.
NAS storage can share storage space with any client in the local area network. However, the connection speed of NAS storage is limited because only one network connection is available.
SAN storage is high-capacity and high-speed. There are one or more servers are connected to multiple disk arrays through optical fibers to share capacity. Data security and read/write speed are guaranteed.
4. Redundant storage
RAID array. Data security is guaranteed.
Data backup. Make multiple copies of the video and save them.
Server cluster. Multiple servers work at the same time, one hot standby, one failure, and the other seamless replacement.
Multi-terminal storage. The video is transferred to different storage terminals for recording and saving.
Ⅳ. The common storage system framework
Small surveillance system: edge storage, the video is stored in the front camera SD card.
P2P mode: the front-end camera is connected to the cloud platform, P2P access, and storage. It can also be stored locally.
Medium monitoring system: storage server + RAID array, client management.
Large-scale centralized storage monitoring system: multiple storage services, load balancing, and storage capacity can be expanded at any time.
Large-scale distributed storage monitoring system: local storage in different regions and centralized management.