Virtualization

Managing disk storage was once simple. If we needed more space, we got a bigger disk drive. But data storage needs grew, so we started adding multiple disk drives. Finding and managing these became harder and took more time, so we developed RAID, network-attached storage and storage-area networks. Still, managing and maintaining thousands of disk drives became an ever more onerous task.

The answer to this dilemma is storage virtualization, which adds a new layer of software and/or hardware between storage systems and servers, so that applications no longer need to know on which specific drives, partitions or storage subsystems their data resides. Administrators can identify, provision and manage distributed storage as if it were a single, consolidated resource. Availability also increases with storage virtualization, since applications aren’t restricted to specific storage resources and are thus insulated from most interruptions.

Also, storage virtualization generally helps automate the expansion of storage capacity, reducing the need for manual provisioning. Storage resources can be updated on the fly without affecting application performance, thus reducing downtime. Because virtualization operates as an intermediate layer, it becomes the primary interface between servers and storage. Servers see the virtualization layer as a single storage device, while all the individual storage devices see the virtualization layer as their only server. This makes it easy to group storage systems, even devices from different vendors into tiers of storage.

This layer shields servers and applications from changes to the storage environment, letting users easily hot-swap a disk or tape drive. Data-copying services are also managed at the virtualization layer. This means that data replication, whether for snapshot or disaster recovery, can be handled entirely by the virtualization system, often in the background, with a common management interface. Because data can be moved at will, lightly used or outdated data can be easily moved to slower, less-expensive storage devices. Small companies running business server applications on several computers can take advantage of virtualization and consolidate the running of backend software into one or two modern, reliable and fast computers.

Think of an ordinary office where each computer is paired with a UPS to safeguard against power fluctuations and outages. Each PC will have its own monitor and keyboard. Maintaining several PCs is not difficult especially if these are contemporary machines. However, it may be tricky to keep older PCs running especially when parts like memory, compatible hard drives and video cards are hard to find.

Virtualization divides a computer’s resources into several execution environments such that through machine simulation and emulation, multiple operating systems are allowed to execute on one machine. Each operating system instance is a virtual machine complete with virtual hardware and storage. It is possible to create a virtual machines with hardware not found on the host computers. Virtualization is highly feasible now because today’s fast and modern machines are more than capable of running legacy applications. It becomes a very attractive option when such legacy applications are run intermittently and do not consume much computer time.

Small businesses can purchase one or two modern computers and use virtualization to recreate their IT infrastructure. For example, you can have one virtual machine acting as a print as well as a file server. You can even create a virtual machine with the specs of a 10 year old computer for running old but indispensible software. An ideal scenario for most companies that are running legacy applications and yet have to upgrade their infrastructure.

If you are looking to have multiple machines at your office or home, you should seriously look at investing in some form of virtualization. It safes a lot of money and also utilizes them to their fullest capacity.