Storage virtualization has long been considered a bottleneck impeding virtualization. But in a few years, storage virtualization has proven itself in the value of large enterprises, small-scale solutions will be expensive changes to affordable products. The emergence of midrange storage arrays, storage virtualization enables small and medium enterprises significantly reduce the burden of storage management. At the same time, from the top manufacturers of specialized solutions for enterprises with large-scale SAN provide the best return on investment (ROI) storage virtualization in the main storage and physical storage to create an abstract layer, which obscures the individual storage device characteristics. When performed in a SAN, it is all the block-level storage management provides a single point. Simply put, storage virtualization from multiple, different types of network storage device brings together the physical storage can be used for the host provides virtual storage capacity.
Apart from the physical disk arrays composed of different storage pool, the storage virtualization in a unified way also provides a number of services. Including the logical unit number (LUN) camouflage, series, and the basic capacity of groups and stripping capacity management extended to the streamlining of automatic configuration, automatic capacity expansion and automatic data transfer, and then extended to data protection and disaster recovery, which includes the snapshot and mirror. In short, virtualization solutions can be used as a central control point, and strengthen storage management strategy to achieve higher SLA
Perhaps the block-level virtualization provides the most important service is the order of data transfer. For large enterprises, mobile data is a long-term problem. As the old equipment has been eliminated, and new equipment are being added to the network, block-level storage virtualization allows data migration without any loss in case of migration from one device to another device. Storage administrators need only routine maintenance, without prejudice to the application or the user to replace the old storage arrays circumstances. Production system has been maintained at normal production conditions.
4 architecture solution
In a virtualized SAN network, there are four ways you can pass storage virtualization services: in-band applications, band application, known as the split-path virtualization architecture of the mixed solutions and controller-based virtualization. Regardless of architecture, all the storage virtualization solutions must do three substantive things: keep a virtual disk and physical memory map, including other configuration metadata; configuration changes and management tasks of the implementation of the present order; in the host and storage to transfer data between. In their meta-data handling, control and data path or the path of the three separate streams in the way, there will be differences between the four architectures. These differences affect the performance and scalability.
Band applications in a single device handle metadata, control and data path information. In other words, meta data management and sharing of data path control functions. SAN busy, this is a potential bottleneck, because all host requests must flow through a single point of control. The application of vendors with products through advanced clustering and caching to increase capacity to address this potential scalability problems. Most of these vendors are able to deploy for large enterprise SAN solutions to demonstrate their scalability and performance. In-band solutions, including DataCore's SANsymphony, FalconStor's IPStor and IBM's SAN Volume Controllers.
Band application of the meta data management and control operations out of the data path, the will and turning a separate calculation engine. The obstacle is the software agent must be installed on each host. Software agents that work is collected from the data stream metadata and control requirements, pre-sent them to deal with external applications, so that the host is more focused on data transmission and storage. Band applications is the only provider of LSI Logic Corporation, the launch of StoreAge products are suitable for band or split-path.
Split-path system can make intelligent switch port-level processing power stripped from the data path, metadata and control information. And the band used in different host within the strip path, split-path system is the separation of the network data and control paths. Split-path system, metadata and control information will be sent to the band before the compute engine for processing, then the data path information to the storage device. Therefore, the split-path system reduces the demand on the host-level agents.
Overall, the split-path virtualization software to run on intelligent switches. Split-path virtualization controller provider for the EMC Corporation (Invista), Incipient Inc. and LSI Logic Corporation (StoreAge SVM).
Array controller is the most common level, virtualization services are deployed here. However, only a virtual storage system controller in the physical hard disk. However, this situation is changing. Improvement on the old program is the deployment of virtualization in the controller, intelligent, so you can come to their internal and external storage virtualization. And the application of the same with the controller to process data, control and metadata are three paths. Hitachi Universal Storage Platform is the controller-based virtualization program representative.
File Virtualization
The same as simplify SAN management, file virtualization and enterprise NAS systems significantly reduce the complexity and the Board related to restrictive. We have recognized that the data capacity of disorder is to explode. This, IT industry is almost no effective way to control the data. File virtualization provides us with a solution.
File virtualization abstracts the physical file servers and NAS equipment, the potential features of a physical device to create a unified namespace. Name space is only on the directory and file and their corresponding meta-data level of a novel argument, which relates to a single machine or file system. Based on a single name space through the introduction of multi-file systems and devices, file virtualization provides a directory and file a single view, giving administrators a single point of control management data.
File virtualization and storage virtualization, many of the advantages are the same. The same as with the storage virtualization, file virtualization can be ordered from one device to another device to transfer file data. Storage administrators need only routine maintenance of NAS devices, without prejudice to the application or the user to replace the old storage arrays circumstances.
When the introduction of cluster technology, the file virtualization can significantly enhance the scalability and performance. Compared with a single NAS device, a NAS cluster can provide faster throughput and IOPS multiple orders. HPC (High Performance Computing) rely heavily on file virtualization technology transfer and scalable data access.
3 architecture solution
The current file virtualization is still in the initial stage. All along, the only solutions from different vendors for different usage patterns, there is no one solution fits all model. Currently on the market there are three different file virtualization solution: integrated platforms, the name space derived from the name of the cluster storage space, network-based virtualization namespace.
Integration platform is the host file system namespace extension. Such a name space for multi-site collaboration, but their lack of extensive document control, limited to a single file system or operating system. Are represented by the Brocade StorageX, NFS v4 and Microsoft's Distributed File System (DFS).
Clustered storage systems combines clustering and advanced file system technology, to create a modular extension system, should have been growing capacity requirements NFS and CIFS. Clustered storage system is ideal for high performance applications, the integration of multiple file servers into a single high-availability systems. The solution is represented by Exanet, Isilon, Network Appliance (Data ONTAP GX) and HP (PolyServe).
Network-based virtualization namespace can be installed in the network, located between the client and the NAS device the device (usually the network file manager) to create. While these devices are essentially file-level agreements as a router or switch, but they can cross the name of the file server to provide virtual space, the routing between the client and store all of the NFS and CIFS information. NFM devices can be deployed to the band or band. Network-based virtualization layer of the column name space is ideal for storage deployment and other needs of the case ordered the transfer of data.