The composition and application of virtualization technology in deep analysis cloud storage

Storage Domain International Authority SNIa (Storage Network Industry Association) gives the definition of storage virtualization (Storagevirtualization): "By abstracting, hiding, or isolating the internal functions of the storage System/subsystem from applications, compute servers, network resources, Implement storage and data management independent of applications and networks. Storage virtualization technology is to abstract the underlying storage devices unified management, to the server layer to mask the specificity of storage equipment hardware, but only to retain their unified logic characteristics, so as to achieve a centralized storage system, unified and convenient management.

Compared with traditional storage, the advantages of virtualization storage are mainly reflected in: high disk utilization, traditional storage technology, disk utilization is generally only 30-70%, and the use of virtualization technology disk utilization up to 70-90%, storage flexibility, can adapt to different vendors, different types of heterogeneous storage platforms, Provides greater flexibility for storage resource management, easy to manage, provides a centralized management of large capacity storage systems, and avoids the management headaches associated with storage device expansion; better performance, virtualized storage systems for load balancing, The bandwidth required for each data access is reasonably allocated to each enclosure to improve the overall access bandwidth of the system.

There are a variety of classifications for virtualized storage, ranging from a large aspect to a classification based on the location of virtualization in the I/O path, sorted according to the different control paths and data paths. Depending on where virtualization is implemented in the I/O path, virtualized storage can be divided into virtual storage of hosts, virtual storage of the network, and virtual storage of storage devices. Depending on the control path and data path, virtualized storage is divided into symmetric virtualization and asymmetric virtualization.

System composition of virtualized storage

A typical storage mode in cloud storage is distributed storage. In this way, the use of Out-of-band virtualization is generally used to manage storage devices, and metadata management and data transmission are done through IP networks. This virtualized storage system consists of four different types of storage devices.

Client：

Clients provide customers with a wide range of application services, such as World Wide Web services, databases, file services, scientific computing, etc. The client runs the storage agent software, and provides access to the network virtual equipment supply program.

Configuration Management Server:

The configuration Management Server is used for system configuration and management. Log on to the cloud storage platform via the Internet, Telnet, or other interface to remotely configure and manage the entire storage system.

Meta Data server:

The metadata server (MDS) of the cloud storage System manages the layout information of the entire system's metadata and object data, and is responsible for the system's resource allocation and network virtual disk address mapping. Global virtualization Storage Management software and cluster management software deployed on the MDS can manage the configuration and operation of the entire storage system. In addition, MDS uses redundant management software to achieve data redundancy between common storage nodes.

Object Storage node:

Each storage node is a stand-alone storage device that is responsible for storage, backup, migration, and recovery of object data and is responsible for monitoring the health and resource conditions of other storage devices. At the same time, the storage node runs virtualized storage management software and stores the data required by the application.

Three-tier model for virtualized storage

According to the composition and characteristics of cloud storage system, the model of virtualized storage can be divided into three layers: physical device virtualization layer, storage node virtualization layer, storage Area Network virtualization layer.

The three-layer virtualization storage model greatly reduces the complexity of storage management, effectively encapsulates the complexity and diversity of the underlying storage devices, and makes the system more scalable and flexible. By adding storage devices to a storage pool and simply configuring them, users can create virtual volumes without having to focus on the physical storage capacity of individual devices in the system and the properties of the storage media to achieve unified storage management.

Physical Device Virtualization Layer:

Mainly used for data block-level resource allocation and management, using the underlying physical device to create a continuous logical address space, that is, storage pool. Depending on the properties of the physical device and the needs of the user, the storage pool can have several different data attributes, such as read and write features, performance weights, and reliability levels. Storage devices on demand, as a logical Volume manager, can allocate logical volumes from storage pools, dynamically allocate storage resources, and manage the mapping and forwarding of data blocks.

Storage Node Virtualization layer:

Enables resource allocation and management between multiple storage pools within a storage node, consolidating one or more allocated storage pools into a unified virtual storage pool within the storage node scope. This virtualization layer is implemented by the Storage node virtual module within the storage node, the storage device that manages on-demand, and on the storage Area Network virtualization layer.

Storage Area Network Virtualization layer:

Enables the allocation and management of resources between storage nodes, and centrally manages storage pools on all storage devices to form a unified virtual storage pool. This virtualization layer is implemented by Virtual Storage Management module on virtual Storage Management Server to manage the resource allocation of virtual storage system in an Out-of-band virtualization way, providing address mapping, querying and other services for virtual Disk Management.

Wide Application

Virtualization technology has been widely used in the storage field.

Each storage device manufacturer has launched its own virtualized storage offerings. Remarkably, Huawei offers an enterprise-class virtualization storage service, with virtual machines for cloud computing and networked storage servers, as well as VTL virtual tape libraries and vis products. At the same time, Huawei has also applied the virtualization technology in the cloud storage system, realized the virtualization of the metadata server, the vosn of the object storage server, the VMDS of the data container and so on.

Virtualized storage has started to scale applications in a variety of industries. These applications include:

Data center: The application of virtualization technology to provide computing and storage Services Center, Network Management Center, Disaster Recovery Center, it resource Leasing center and other services.

Telecommunications industry: With the development of industry, the telecommunications industry faces two challenges, on the one hand, reduce the cost of IT infrastructure, on the other hand, improve the availability of it architecture. Virtualization technology is an effective solution to this problem.

Bank Securities and insurance Industry: the use of virtualization for disaster tolerance, to take the "three centers" scheme, namely production center, the City Disaster Preparedness Center, off-site disaster Preparedness center. With the City Disaster Preparedness Center is responsible for general disaster prevention, off-site disaster preparedness center to prevent large-scale disaster. Virtualization technology enables virtualization management across data centers within a unified virtualized infrastructure.

Government Information System: the construction of government data storage system is being paid more attention than before. The system utilizes the advanced storage virtualization technology, establishes the unified, the standard, the sharing data resource storage platform, can effectively manage the huge, numerous, the complex data and the related equipment, enhances the resource utilization rate, and establishes the comprehensive data security safeguard system.