Four major storage technology to analyze the advantages and disadvantages

Four major storage technology to analyze the advantages and disadvantages

The data storage problem is very important, however, in the actual application is a series of wrong things. Often appear drop disk, volume lockup and many other problems, seriously affecting the normal use of the overall system, so the data dedicated storage has become one of the most concerned about the security products on the market.

The traditional way of storing data

In the current digital realm, the most commonly used are the following four types of storage: hard disk, DAS, nas, san.

1. hard disk

Whether it is a dvr, dvs rear-mounted hard disk or a server directly behind the expansion cabinet, it can be used to connect to the hard disk. It should be said that the use of hard disk storage, and can not be regarded as a strict sense of the storage system.

Second, its expansion capability is extremely limited, when the video time is more than 60 days, often can not meet the storage needs of the video time;

Third, can not realize the data centralized storage, the later maintenance costs are high, especially in the dvs after the way to hang the hard disk, the maintenance cost is often more than the cost of the purchase within a year.

It should be said that hard disk storage is not suitable for large-scale digital video surveillance system applications. In particular, the need for a long time to record the digital video surveillance system. Generally, this approach is coexisting with other storage methods in the same system, as a buffer for other storage methods or emergency replacement.

2. DAS (direct attached storage)

DAS (direct attached storage), all known as direct attached storage, using the DAS way can be very simple to realize the platform capacity expansion, at the same time, the data can provide a variety of rald level of protection.

When using DAS. Deploy the relevant .hba card on the video storage unit. This is used to establish a data channel with the back-end storage device. The front-end video storage unit can be a dvr or a video storage server. The channel can use optical fiber, ip network cable, sas cable or even usb, 1394 cable, etc..

The DAS approach does not simultaneously support many video storage service unit access at the same time, and its expansion capability is heavily dependent on the selected storage device's own expansion capability. So in a large digital video surveillance system, the application of DAS storage will cause a great deal of difficulty in system maintenance.

It is because of these characteristics of DAS storage that this storage method is generally used for dvr expansion or small digital video surveillance projects.

3. NAS (network attached storage)

NAS (network attached storage). All known as network attached storage, is a professional network file storage and file backup device, or known as network direct attached storage device, network disk array. At the same time NAS can provide a variety of raid level protection for data.

NAS devices and multiple video storage service units are connected via an ip network, communicating in accordance with the tcp/ip protocol, and transferring data in a file i/o (input/output) manner. A NAS unit includes a core processor, a file service management tool, and one or more hard disk drives for data storage.

Using NAS can simultaneously support multiple hosts to read and write at the same time, with excellent **** enjoyment of performance and scalability; at the same time, NAS can be used in complex network environments. The deployment is also very flexible.

But because NAS uses the cif/nfs protocol for file-level transmission of data, so the network overhead is very large, especially in the write data when the bandwidth utilization is generally only 20% -40%. Therefore, NAS is generally used in small networked digital video surveillance systems or just for part of the data **** enjoyment storage.

4. SAN (storage area network)

SAN (storage area network), known as the storage area network, through the switch and other connectivity devices will be connected to the disk array and the related servers connected to a high-speed dedicated subnet. At the same time, SAN can provide multiple raid levels of protection for data.

SANs provide a dedicated, highly reliable storage network. It allows for independent increases in their storage capacity, and also makes management and centralized control (especially when all storage devices are grouped together) much simpler. It is because of these characteristics, SAN architecture is particularly suitable for large network digital video surveillance system storage applications, can cope with thousands, tens of thousands of front-end monitoring point of storage.

Currently, SANs are divided into FC-SAN (Fiber Optic Storage Area Network) and ip-SAN (Ethernet Storage Area Network). The difference between them is the connection lines and the use of data transfer protocols. Although FC-SAN can ensure more stable and efficient transmission due to the use of dedicated protocols, its deployment method, construction costs are much higher than ip-SAN, so the current large-scale network digital video surveillance system is more often used in ip-SAN architecture.