jewelry wholesale software What does SAN and RAID have to do?

999 silver jewelry wholesale The development of the storage area network (SAN) is currently in a period of full speed, and various concept layers are emerging. Among them, the epoch -making significance is the proposal of the concept of virtual storage. Compared to the traditional switch plus the RAID array, the host directly access the SAN structure of the hard disk in the array through the hardware layer. The positioning of the virtual storage is to abstract the data storage function from the actual and physical data access process, so that ordinary users are in the use When accessing the data, you don't need to care about the configuration parameters, physical location and capacity of the specific storage device, thereby simplifying the difficulty of user and system managers.

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The multimedia processing business around digital and networked, the storage system network platform has become a core platform. At the same time, various applications have been applied. The requirements of the platform are also getting higher and higher, not only in the storage capacity, but also include data access performance, data transmission performance, data management capabilities, storage expansion capabilities, and so on. It can be said that the advantages and disadvantages of the comprehensive performance of the storage network platform will directly affect the normal operation of the entire system.

In order to meet these requirements, an emerging technology is getting more and more attention, that is, virtual storage technology.

The virtualization technology is not a very new technology. Its development should be said to develop with the development of computer technology. It first started in the 1970s. Due to the storage capacity at that time, especially the cost of memory capacity and small capacity, it was greatly limited to large applications or multi -program applications. In order to overcome such restrictions, people use virtual storage technology. The most typical application is virtual memory technology. With the continuous development of computer technology and related information processing technology, people's demand for storage is increasing. Such demand has stimulated the emergence of various new technologies, such as better disk performance and larger capacity. However, in a large number of large and medium -sized information processing systems, a single disk cannot meet the needs. In this case, storage virtualization technology develops. In this development process, several stages and several applications are also. The first is the disk strip set (RAID, can be fault -tolerant) technology, which gather multiple physical disks through a certain logical relationship to become a large -capacity virtual disk. As the amount of data continues to increase and the requirements for data availability, another new storage technology emerges, that is, the storage regional network (SAN) technology. SAN's wide -rangeization aims to implement the storage equipment into a public facilities, and any person or any host can obtain the data they want anytime, anywhere. At present, more discussions include ISCSI, FC Over IP and other technologies. Since some related standards have not been finalized, the publicization and storage network widespread storage equipment is an irreversible trend.

. The concept of virtual storage

The so -called virtual storage is to centrally manage multiple storage medium modules (such as hard disks, RAID) through certain means, all storage, all storage The module is uniformly managed in a storage pool. From the perspective of the host and workstation, it is not a number of hard disks, but a partition or volume, as if it is a large capacity (such as more than 1T) hard disk Essence This storage system that can uniformly manage multiple and multiple storage devices and provide users with large -capacity and high data transmission performance, which is called virtual storage.

. The classification of virtual storage

The development of virtual storage has no unified standards. There are two main methods in terms of the topological structure of virtualized storage: ie symmetrical formula With asymmetric formula. Symmetric virtual storage technology refers to the virtual storage control equipment and the storage software system and exchange equipment set. outside. There are two ways to achieve the principle of implementation of virtualized storage; that is, data block virtual and virtual file systems. The specific as follows:

1. Symmetric virtual storage

Figure 1 Symptoms of symmetrical storage solution

In the symmetrical formula virtual storage structure shown in Figure 1, the storage control device High Speed ​​Traffic Directors (HSTD) integrated with the storage pool subsystem Storage Pool to form SAN Appliance. It can be seen that the storage control device HSTD plays a core role in the process of data exchange between the host and the storage pool. The virtual storage procedure of this scheme is like this: the storage management system embedded by HSTD will virtue the physical hard disk in the storage pool as logical storage unit (LUN) and perform port mapping (specify what ports can be seen by a certain LUN) The host side mapping the visible storage unit into a disk format that can be recognized by the operating system. When the host writes the data to the SAN Appliance, the user only needs to specify the data to be specified as a disk (LUN) that is mapped by himself. The data passes through the high -speed parallel port of HSTD. Complete the transition from LUN to physical hard disks. In the process, users see only virtual logic units, and do not care about the specific physical organization structure of each LUN. This scheme has the following main characteristics:

(1) Use a large -capacity and high -speed cache to significantly improve the data transmission speed.

This cache is the intermediate medium on the I/O path between the host and the storage device widely used in the storage system. When the host reads the data from the storage device, it will read the data connected to the current data storage position into the cache, and keep the multiple -called data in the cache; when the host reads the data, it can be able to get a high probability. Find the required data from the cache. Read out directly from the cache. The speed of when reading data from cache is only affected by the speed of the spread of the electrical signal (equal to the speed of light), so it is greatly higher than the speed of the plate mechanical rotation when reading data from the hard disk. When the host writes the data to the storage device, first write the data into the cache, stop writing on the host side to stop, and then write the data to the hard disk from the cache. R n (2) Multi -port parallel technology eliminates I/O bottlenecks.

This The control port and logic disk in the traditional FC storage device are fixed relationships, and a hard disk can only control its controller port. In the symmetrical virtual storage device, the relationship between the storage port of San Appliance and LUN is virtual, which means that multiple hosts can access the same LUN through multiple storage ports (up to 8); Under the premise, the more ports of parallel work, the higher the data bandwidth.

(3) The logical storage unit provides high -speed disk access speed.

In the video application environment, when the application reads and write data, the data block of fixed size is used as a unit (from 512byte to 1MB). In order to ensure the bandwidth requirements of the application, the storage system is often designed to transmit data blocks above 512BYTE in the size to achieve its best I/O performance. In the traditional SAN structure, when the capacity demand is increased, the only solution is that multiple disks (physical or logical) are bound to a zone set to achieve large capacity LUN. In the symmetrical virtual storage system, the host provides a real large -capacity and high -performance LUN, instead of a logical volume with poor performance in the zone set. Compared with the zone set, Power Lun has many advantages. For example, the large I/O Block will be accepted by the storage system to effectively improve the data transmission speed; and because there is no processing process of the zone set, the host CPU can be lifted very well The big burden improved the performance of the host.

(4) The fault tolerance performance of the pair of HSTD system.

In the symmetrical virtual storage system, HSTD is a must -have place for data I/O. The storage pool is a data store. Because the data in the storage pool has a fault tolerance mechanism to ensure safety, users will naturally think of whether HSTD has fault tolerance protection. Like many large storage systems, in mature symmetrical virtual storage systems, HSTD is formulated in pairs. Each pair of HSTDs realize the consistency and communication of cache data through the network management service embedded by SAN Appliance.

(5) SAN can be convenient to connect to the switching device on the SAN Appliance to achieve SAN of the large -scale Fabric structure.

Because the system maintains the standard SAN structure, it provides technical guarantee for the expansion and interconnection of the system, so it can easily connect the switching device on SAN Appliance to achieve SAN of the large -scale Fabric structure.

2. Asymmetric virtual storage system

Figure 2 Asymmetric virtual storage system schematic diagram

The asymmetric type virtual storage system charts shown in Figure 2, in the network Each host and virtual storage management equipment are connected to the disk array. Among them, the data path of the host reaches the disk array through the FC exchange device; the virtual storage device performs virtualized operations on the disk array connected to the network, and the LUN in each storage array is Virtual is a logic zone set (Strip), and specifies the access permissions of each Strip on each host on the network (writing, readable, prohibited access). When the host wants to access a certain Strip, first access the virtual storage device, read Strip information and access permissions, and then access the data in the actual Strip through the exchange device. In the process, the host only recognizes the logic Strip without directly identifying the physical hard disk. This scheme has the following characteristics:

(1) The capacity combination of different physical hard disk arrays is combined to achieve virtual zone sets. The system's available bandwidth is increased.

(2) In the case of sufficient number of switch ports, two virtual storage devices can be installed in one network to achieve redundant STRIP information and access permissions.

. There are some deficiencies in this scheme:

(1) This scheme is essentially a zone set -disk array structure. Once a disk array in the zone concentration is concentrated, The controller is damaged, or the copper cable and GBIC damage to this array to the switch path will cause a virtual LUN offline, and the zone set itself has no fault tolerance. Essence

(2) Since the increase in the bandwidth of this scheme is achieved by array port binding, and the effective bandwidth of the ordinary fiber channel array controller is only about 40MB/s, so it must reach hundreds of megers The bandwidth means to call a dozen arrays, which will occupy dozens of switch ports. Among the small and medium -sized networks with only one or two switches, this is not possible.

(3) Because the performance of various brands and models of disk array is not exactly the same, if the array of different brands and models is binded for the purpose of virtualization, it will bring a problem: That is, the speed of each concurrent data flow when the data is written or reads, which means that the original data packet order is disrupted after the transmission. Affect system performance.

3. Data block virtual and virtual file system

above analyzes the similarities and differences between symmetrical and asymmetric virtual storage schemes from the perspective of the topology structure. There are also two ways to act as the principle of realization of virtualized storage; that is, Data block virtual and virtual file system.

The data block virtual storage scheme focuses on solving the conflict and delay problems in the data transmission process. Among the large Fabric structures composed of multiple switches, because multiple hosts access storage equipment through multiple switch ports, the problem of delay and data block conflict is very serious. The data block virtual storage scheme uses virtual multi -port parallel technology to provide a high bandwidth for multiple clients, which minimize the occurrence of delay and conflict. In practical applications, the data block virtual storage scheme is symmetrical in symmetry. The topology structure is an expression form.

The virtual file system storage scheme focuses on solving the problem of security mechanisms for large -scale network file sharing. Specify different access rights to different sites to ensure the security of network files. In practical applications, the virtual file system storage scheme is expressed in asymmetric topology structure.

. The implementation of virtual storage technology

The virtual storage is mainly divided into the following:

1. The virtual storage on the server side n
The server manufacturers will implement virtual storage on the server side. Similarly, software manufacturers will also implement virtual storage on the server platform. The implementation of these virtual storage is mapped to the peripheral storage device through the server side. Except for allocating data, there is no control to the outer storage device. The server is generally realized through logic volume management to achieve virtual storage technology. Logic volume management provides a virtual layer for the volume mapped from physical storage to logical. The server only needs to handle the logic volume without managing the physical parameters of the storage device.

This use of this virtual storage system, the server side is a performance bottleneck, so it is rarely used in the field of multimedia processing.

2. Virtual storage at the storage subsystem

. Another place to implement the virtual storage device itself. This virtual storage is generally implemented by storage manufacturers, but it is likely to use the exclusive storage products of manufacturers. To avoid this incompatibility, manufacturers may cooperate with servers, software or network manufacturers. When the virtual storage is implemented on the device end, the logic (virtual) environment and physical equipment are in the same control range. The benefits of this are: virtual disk highly effectively use disk capacity, virtual tape high effectively uses tape media.

The virtual storage device on the storage subsystem is mainly connected to the server through large -scale RAID subsystems and multiple I/O channels. The intelligent controller provides LUN access control, cache, and other data replication such as data replication Management functions. The advantage of this method is that the storage equipment administrator has complete control over the equipment, and through separation with the server system, the management of storage can be isolated from multiple server operating systems, and the hardware parameters can be easily adjusted.

3. The network device side implements virtual storage

The network manufacturers will implement virtual storage on the network device side, and the logical mirror is mapped to the peripheral storage device through the network. In addition to allocating data, there is no control to the external storage device. The implementation of virtual storage on the network side has its rationality because its implementation is neither on the server nor the storage device side, but between the two environments. It may be the most "open" virtual implementation environment. It is possible to support any server, operating system, application and storage equipment. Technically, there are two types of structures for the implementation of virtual storage on the network end: symmetrical and asymmetric virtual storage.

Irds from the actual situation of the current virtual storage technology and products, based on hosting and storage -based methods for the initial adopter, because they do not need any additional hardware, but for different other, but for different other, but for different other, for different other, but for different other, but for strangeness, but for strangeness, but for different other, but for different other, but for different other, but for different other, but for different other, but for different other, but for different other, but for different other, but for different other, but for different other, but for different other, but for different other, but for different other, but for different other, but for different other, but for different other, but for different other, but for different other, but for different other, but for different other, but for different other, but for different other, but for different other, but for different other, but for different other, but for different other, but for different other, but for different other, but for different other, but for different other, but for different other, but for different other, for strangeness. As far as the storage system and operating system, the system operates is not very good. The method of interconnection equipment is between the two. It avoids some security issues. It has a strong function of storing virtualization. It can reduce the load of a single host, and at the same time can obtain a good expansion.

Moly virtual storage technology, its purpose is to provide a high -performance, secure, stable, reliable, scalable storage network platform to meet the harsh requirements of the program production network system. According to the comprehensive performance price ratio, in general, when the host and storage device -based virtual storage technology can ensure the data processing capacity requirements of the system, these two virtual storage technology frameworks are convenient, the management is simple, and the management Maintenance is easy, the product is relatively mature, and the performance price is higher. In the case of simply storage device's virtual storage technology that cannot guarantee the performance requirements of the storage system, we can consider adopting virtual storage technology based on interconnected devices.

. The characteristics of virtual storage

Virtual storage has the following characteristics:

(1) Virtual storage provides a large -capacity storage system centralized management The means of means of a unified management of a link (such as a server) in the network avoids the troubles of management caused by the expansion of the storage equipment. For example, using general storage systems, when adding new storage devices, the entire system (including many user devices in the network) needs to be re -configured in order to add this "new member" to the storage system. When using virtual storage technology to increase new storage devices, we only need a network administrator to make a relatively simple system configuration change on the storage system. The client does not need any operations. It feels like the capacity of the storage system increases.

(2) The most valuable feature of virtual storage for video network systems is that it can greatly improve the overall access bandwidth of the storage system. The storage system is composed of multiple storage modules, and the virtual storage system can make a good load balance. The bandwidth required for each data access can be reasonably distributed to each storage module. In this way Essence For example, there are 4 storage modules in a storage system, and the access bandwidth of each storage module is 50Mbps, then the total access bandwidth of this storage system can approach the sum of the bandwidth of each storage module, that is, 200Mbps.

(3) Virtual storage technology provides better flexibility for storage resource management. It can be concentrated in management and use of different types of storage equipment to ensure the investment of the storage equipment purchased by users in the past.

(4) Virtual storage technology can provide some other useful functions to the network system through management software, such as remote mirrors, data snapshot (Snapshot), etc. without the server.

. The application of virtual storage Due to the above characteristics of virtual storage, virtual storage technology is gradually becoming the mainstream technology for shared storage management. The application is as follows:

1. Data mirror

The data mirror is to establish a data copy between different storage devices through a two -way synchronization or one -way synchronization mode. A reasonable solution should be able to provide mirrors to make mirrors between the same storage array and different storage arrays without relying on the support of equipment manufacturers and operating systems.

2. Data replication

The long -range data migration (usually asynchronous transmission) through IP address (usually asynchronous transmission) is an extremely important data disaster recovery tool for enterprises of different sizes. A good solution should not rely on special network equipment support, and at the same time, it should not rely on hosting to save corporate management costs.

3. The tape backup enhancement equipment

has developed rarely newly developed in tape backup technology in the past few years. Nevertheless, a network storage device platform should also be able to build bridge roads between tapes and disks to complete backup work at high speed, stable and safely.

4. Real -time compound

For testing, expansion and summary or some other reasons, companies often need to make data compound.

5. Real -time data recovery

The use of magnetic transmission data is the main means of data recovery, but it is often difficult to succeed. One of the important development directions for data management is to transfer the recent score data (which can be a week ago) to disk medium, not tape media. Recovery data with disk is as fast as lightning (all files can be restored within 60 seconds), and they are far more safe and reliable than recovery data with tape. At the same time, Volume data can be restored.

6. Another new direction for the development of the application integration

The storage management development is to close the service close to the application. No managers in the field of information technology will buy it simply for the interest of storage equipment. Storage devices are used to serve applications, such as databases, communication systems, and so on. By integrating the application behavior of the storage device and the key enterprise, it can obtain greater value, and at the same time, it greatly reduces the problems encountered in the operation process.

7. Application of virtual storage in the digital video network

It now I focus on the application of virtual storage in digital video networks.

D digital video network is no longer a strange concept for the radio and television industry. Because it plays an important role in the digitalization of radio and television technology, domestic TV stations at all levels have given it great greatly Pay attention to, and begin to construct and apply systems. In the concept of digital video networks, it completely breaks the traditional structure of a recording machine, an editing system, and a set of broadcasting systems in the past. Workstations, broadcast workstations and program storage workstations are easy to operate and manage. The uploading of the program, the program editing, and the broadcast of the show are completed on different functional workstations, which can improve work efficiency. At the same time, due to the use of non -linear editing systems, in addition to the compression loss during collection. In the process of production and broadcasting, there will be no more losses during the production and broadcasting process, and the technical quality of the program will be greatly improved.

In existing video network systems, although the main frequency of the computer, the network transmission rate, and the performance of the switching equipment can already meet the requirements of most applications, but the access bandwidth of the storage equipment is The problem has become a main performance bottleneck of the system. Video editors and production have the characteristics of large data storage, high code flow, strong real -time, and important security. This requires that the storage technology and products applied to the video field must have sufficient bandwidth and stability.

In single -machine applications, in order to ensure that a editor site has enough data bandwidth, SCSI technology, local independent disk redundant array RAID (RENDANT ARRAY of DISKS) technology Widely used, it combines several SCSI hard disks with a controller to form a large capacity, respond quickly, and high reliability storage subsystems. From the user, it can be used as a logic disk or virtual disk, which greatly improves the data transmission rate and the data transmission rate and Storage capacity, while using error correction technology to improve the reliability of storage and meet the requirements of bandwidth.

The development of editing data is required with the development of program production needs. At this time, SCSI network technology can be used to implement this requirement. Several editorial sites are equipped with high -performance SCSI adapters, which are connected to the shared SCSI disk array, which can not only realize several sites sharing data, but also ensure the working bandwidth of each single machine.

The mature application of optical fiber channel technology has a milestone significance for the development of video networks. From then on, the connection distance between the host and the shared storage device is limited from several meters, ten meters to several hundred meters, thousands of thousands, thousands Mi, with the fiber -fiber channel exchange equipment, the network scale has been expanded several times and ten times. At this time, the FC (Fibre Channel optical fiber channel) disk array -RAID fault -tolerant technology, the high bandwidth, and large capacity of the relative SCSI, and became the core storage device in the video network.

With the development of the scale of the TV station, the application of a large -scale video network in a full -scale level is proposed. Under such demand, more advanced storage technology and products must be introduced into the video field. The development of the storage area network (SAN) is currently in a period of full speed, and various concept layers are emerging. Among them, the epoch -making significance is the proposal of the concept of virtual storage. Compared to the traditional switch plus the RAID array, the host directly access the SAN structure of the hard disk in the array through the hardware layer. The positioning of the virtual storage is to abstract the data storage function from the actual and physical data access process, so that ordinary users are in the use When accessing the data, you don't need to care about the configuration parameters, physical location and capacity of the specific storage device, thereby simplifying the difficulty of user and system managers.

In designing a video network system, the selection of the storage system mainly considers the following factors: (1) the overall bandwidth performance; (2) management; (3) security; (4) scalability; (5) System cost.

of course, these factors sometimes restrict each other, especially the relationship between system cost and performance and security. How to seek reasonable, practical and economic cooperation between these factors is a subject that needs to be resolved. The emergence of virtual storage technology provides us with a solution to a practical and feasible high -performance price ratio when building a video network system.

It's topology, symmetrical solutions have higher bandwidth performance and better security characteristics, so it is more suitable for large -scale video network applications. Asymmetric schemes are more suitable for applications of ordinary LAN (such as office networks) because the principle of virtual files is adopted.