Network storage solution: storage area network (SAN)

Network storage solution: storage area network (SAN)

Storage area network concept
SAN (Storage Area Network) is a high-speed subnet. The devices in this subnet can offload traffic from your main network. Usually SAN consists of disk array (RAID) connected to Fibre Channel (Fibre Channel). The data communication between the SAN and the server and the client is through SCSI commands instead of TCP / IP, and the data processing is "block level". SAN can also be defined as centered on data storage. It uses a scalable network topology and provides a multi-channel selectable data exchange between any nodes within the SAN through the direct connection of optical channels with high transmission rate And centralized data storage management in a relatively independent storage area network. SAN will eventually achieve maximum data sharing and data optimization management under various operating systems, as well as seamless expansion of the system.

Composition of SAN
In the SAN, there are some dedicated hardware and software. The hardware includes FC card, FC HUB, FC switch, storage system, etc. The software is mainly the driver and storage management software of FC control card for various operating systems. The following briefly introduces these devices:

FC card: mainly used for the connection between the host and the FC device.
FC HUB: Internally runs an arbitrated ring topology, and nodes connected to the HUB share 100MB / S bandwidth (or higher).
FC switch: runs Fabric topology internally, and each port occupies 100MB / S bandwidth (or higher) exclusively.
FC storage device: FC connection is adopted, and there can be one or more optical fiber interfaces. FC storage devices usually use optical fiber hard drives, and there are Fibre to SCSI (Fibre to ATA) solutions. SCSI (or ATA) hard drives are cheaper in the entire configuration.
Storage network management software: The main function of storage management software is to automatically discover network topology and mapping, and automatically discover and configure when it increases or decreases in the storage network.
To correctly understand SAN, we better define it in terms of physical architecture. We can see from the figure that high-performance Fibre Channel switches and Fibre Channel network protocols are the key to SAN. We call the network topology with Fibre Channel switches as the backbone the "SAN Fabric". Fibre Channel protocol is another essential feature of SAN. The SAN utilizes the Fibre Channel protocol to load the SCSI protocol to achieve reliable block-level data transmission.

SAN applications
Since SAN is optimized for transferring large blocks of data between servers and storage devices, it is ideal for the following applications:

1. Mission-critical database applications, where predictable response time, availability, and scalability are essential elements.
2. Centralized storage backup, in which performance, data consistency and reliability can ensure the safety of key data of the enterprise.
3. High availability and failover environment can ensure lower cost and higher application level.
4. Scalable storage virtualization can separate storage from direct host connection and ensure dynamic storage partitioning.
5. The improved fault tolerance feature provides high performance and extended distance of Fibre Channel between the host server and its connected devices.
The main advantages of SAN
Facing the rapidly increasing demand for data storage, large enterprises and service providers gradually began to choose SAN as the network infrastructure because of its excellent scalability. In fact, SAN has more significant advantages than traditional storage architectures. For example, traditional server-attached storage is often difficult to update or centrally manage. Each server must be shut down to add and configure new storage. In comparison, a SAN can increase storage without having to go down and interrupt the connection to the server. SAN can also centralize data management, thereby reducing the total cost of ownership.

Using Fibre Channel technology, the SAN can efficiently transmit data blocks. By supporting the transfer of massive data blocks between storage and servers, SAN provides an effective way to back up data. Therefore, the network bandwidth traditionally used for data backup can be saved for other applications.

Open, industry-standard Fibre Channel technology also makes the SAN very flexible. SAN overcomes the traditional cable limitation connected to SCSI, greatly expands the distance between the server and storage, thereby increasing the possibility of more connections. The improved scalability also simplifies the deployment and upgrade of the server and protects the investment of the original hardware equipment.

In addition, SAN can better control the storage network environment, suitable for those transaction-based systems in terms of performance and availability. SAN uses high-reliability and high-performance Fibre Channel protocols to meet this need.

Another strength of SAN is the ability to transfer data blocks to enterprise-level data-intensive applications. In the process of data transmission, the processing overhead of the SAN on communication nodes (especially servers) is less because the data is divided into smaller data blocks during transmission. Therefore, the Fibre Channel SAN is very effective in transmitting large data blocks, which makes the Fibre Channel protocol very suitable for storage-intensive environments.

Reasons to choose SAN

1. Increase capacity. If all the equipment is connected to the SAN, it becomes very simple to increase the storage capacity for one or more servers. Depending on the SAN configuration and server operating system, storage devices can be added or removed without shutting down or restarting the server.
2. Server cluster. Since clusters of heterogeneous servers can view data as a single system image, the SAN structure is actually provided to the scalable cluster in a fully shared manner. Although the use of multi-path SCSI now makes this idea possible, scalability is still a problem because the distance of SCSI is limited. The general SCSI allows a transmission distance of 25 meters, and the performance of the SCSI connector also limits the number of devices connected to the server or subsystem.
3. Data mobility solution. Data movement solutions can move data back and forth between similar or different storage devices. At present, the movement or copying of data is completed by the server or multiple servers. The server reads the data from the source device, and then transmits it to other servers through the LAN or WAN.
4. Backup and recovery solutions. At present, the following two backup and recovery methods are used for data protection of multiple network-connected servers: local backup and recovery, network backup and recovery. The SAN combines the advantages of the above two methods. Its approach is to centrally manage backup and recovery, distribute one or more tape devices to each server, and use the FC protocol to transfer data directly from the disk device to the Tape device.

Problems with SAN
In the past two years, SAN has been gradually understood, recognized, and used by people. SAN replaces the server-based storage model and forms a data-centric storage model. SAN has good performance, more centralized management, and good The ability to expand. However, to this day, interoperability is still the main problem in the implementation process.

The SAN itself lacks standards, especially in management. Although Fibre Channel technology standards do exist, various manufacturers have different interpretations, so the interoperability problem is like a sandstorm, and it is unexpected. Due to some reasons for Fibre Channel technology, the development of SAN is relatively slow. These reasons include: poor interoperability of Fibre Channel equipment; the cost of systems using Fibre Channel technology is very expensive; management of SAN based on Fibre Channel technology is very expensive.

Some SAN vendors set standards through organizations such as SNIA. Others are investing heavily in building interoperability labs to test before launching the SAN. Another way is to outsource SAN. Although SAN vendors have made progress in solving interoperability issues, experts still recommend users to use outsourcing instead of building SANs themselves.

Health Care heat film is mainly used for Far Infrared Sauna Room heat film,health care product, Body Heat Film ,eye massage thin heated element,Infrared Heating Jacket, Flexible Heating Flim for ski suit,Heating Flim For Diving Suit.
we are a professional and leader Chinese exporter of heat film,Customization options (for example: SMT components, flex cable and connectors) can provide the perfect complete solution that can significantly reduce assembly time and increase productivity.Providing a variety of complex shapes design, and different power designs. Membrane in the same piece electrically heated heating circuit can be designed and holding circuit,we are looking forward to your cooperation.

Customized Heating Elements

Health Care Heating Film,Carbon Heating Film,Infrared Heat Film,Infared Heating

ShenZhen XingHongChang Electric CO., LTD. ,