Throughout the years, the growing needs for storage led to the invention of simpler ways to manage file storage. But this isn’t an easy task because storage users also want efficiency and control together with great service levels, all necessary things in order to keep up with an ever-changing business world. This is how file virtualization came into action.
Storage systems rely on special hardware, software, and disk drivers in order to deliver fast and reliable storage for data processing and computing. Managing storage and data is a complex and time-consuming activity; storage virtualization improves this, making it possible to have back-ups and achieving tasks in an efficient matter. This technique is by no means a new one, but it became hugely popular in recent years due to its many benefits. Storage virtualization basically aggregates the physical storage from multiple networks storage devices, so that it looks like a single storage device; beyond the reduced complexity of the entire storage management process, it also offers a better disaster recovery in case the storage area network (SAN) gets destroyed.
Block virtualization and file virtualization
There are two primary types of virtualization that occur when talking about storage systems: block-level virtualization and file-level virtualization. The first type is located in the SAN environment of large businesses and enterprises. It basically means that every block in a block-level system can be controlled as an individual hard drive and the blocks are managed by the server based operating systems.
A physical storage device has a number of blocks and a set of commands to read and write blocks of data which block-level virtualization imitates in order to transmit the same commands and get the same results. Using block-level storage protocols like iSCSI (Internet Small Computer Systems Interface), Fibre Channel or Fibre Channel over Ethernet, the storage blocks are made visible and accessible by the server-based operating system.
File system virtualization fundamentally refers to the aggregation of multiple file systems into a single, larger virtual file system. This technique serves applications that need to access data in the form of files rather than block-by-block and these files are usually found in file systems located on Network Attached Storage (NAS) devices.
One of the main purposes that led to the file virtualization was the desire to shelter the users from the complicated processes pertaining to the storage environment. This storage technology is usually configured using a protocol such as Network File System (NFS) or Server Message Block (SMB)/ Common Internet File System (CIFS).
The advantages of using file virtualization
The virtual file system interface, usually referred to as the v-nod interface is responsible for creating a connection between the physical systems - containing the actual data that is stored – and the logical file systems, which are basically a representation of the physical files. File virtualization has the ability to eliminate the dependencies between the data accessed and the location where the files are physically stored. This means that storage usage and server consolidation have an improved efficiency and that file-migrations can be done with minimized disruptions. This type of virtualization favors a certain level of flexibility for storage managers and increases data mobility thanks to the location independence between file systems, files from the applications and users. It can also provide a solution to file size limitations because it can save storage space for files on different servers.
File virtualization: a global namespace
One of the key benefits brought by file virtualization is the fact that it provides a global namespace to index files on network file servers. A global namespace has the role of simplifying storage management in environments where there are many physical file systems. It’s also a good solution for fast growing environments where data needs to be accessed without having to know where it’s physically located. A global namespace gives an organization the opportunity to access a virtualized file system namespace, while it can also open more storage pools and help reduce the number of mount points in an environment.
All in all, the evolution of storage virtualization means that previously unstructured data has become easier to manage, thus revolutionizing the technological world by transforming multiple network storage devices into what basically amounts to a single storage unit.