Virtual reality

Extending the possibilities of virtualisation according to Sify Technologies' Saji PK.

In the wake of recent recession, companies are going back to the drawing board for solutions that optimise costs. Among the huge IT spenders, this has been driving adoption of a phenomenon that has actually been around for decades – data centre virtualisation. Traditionally, the running a data centre means having standalone computers/servers perform dedicated functions for individual applications. But virtualisation technology allows applications and servers to work in a non-dedicated manner, interacting to get the task done.

Virtualisation is the creation of logical storage, out of physical storage. It involves multi-tenanting of hardware resources, using software technologies. Masking the physical characteristics of resources from the way in which other systems, applications or end users interact with them. In the mainframe era, time-shared, multi-computing environments were the first incarnation of virtualisation. It has been prevalent in some form in servers and storage and of-late, has matured to networks and I/O, as data Centre or DC virtualisation.

So what is virtualisation? Let's take a typical scenario where an end user needs to access an application, on a particular operating system, to recover accounting data, all stored in different servers. Only a small portion of the server's capacity may be used to handle the critical aspect of running an operating system or an application. Virtualisation enables moving of these aspects together logically, so as to be handled out of minimised server space with operating systems, applications, and data coexisting in the same storage area. Virtualisation is a technology which is applied at many level/layers from desktop and laptops to servers, networks, files, applications etc, now on even entire data centres. On a network, virtualisation can allow the creation of single virtual network, in a corporate group that has many external networks, using VLAN and switching technology, besides or virtual routers or virtual firewalls.

Server virtualisation enables virtualization in a network attached server (NAS) – that is, a self-contained computer or server connected to a network of end users. Storage virtualisation for NAS systems is typically available as virtual filers, or independent file systems on the NAS device. NAS virtualisation can refer to creating multiple virtual file servers within a physical file server, or even the virtualising of multiple NAS heads into a single file system. Users in such an environment could access a file/application/OS could be located anywhere in a global network and used as though it were in a single server.

In a storage area network (SAN) model, virtualisation brings up unlimited potential. It differs from NAS scenarios in that it has several storage blocks accessible to the server, which is connected to the network. Here, techniques like fibre channel zoning at the SAN layer and masking of the logical unit address, either at the host side or the storage side, are used for creating virtualised storage groups. It enables huge savings through optimisation of the 'array' or disk spaces. The central virtualisation controller can handle much of the critical tasks like housing the software, OS and so on – freeing up space on the array. It can also enable cross function sourcing of MIS, that is, data from various virtual servers can be culled for business intelligence, using a hyper engine.

But the really big story with virtualisation is the savings delivered. Virtualisation enables any enterprise to lower per gigabyte storage rates that significantly impact IT spending, especially with the emergence of power management technology – that enables moving the computing load together and actually powering off servers that are not it use. Virtualisation in data centres is slated to grow exponentially – from a few hundred virtual machines to several thousands leading us into truly virtual data centres as 2009-10 progresses. So what's next in terms of technology? An emerging winner is cloud computing – where the resources physically located over vast areas can be jointly used as in a public domain for reliable and safe computing. It involves the creation of scalable, publicly available computing environments and leaders like Google and Microsoft are redefining the economics here.

Saji PK, SVP of Technology at Sify Technologies Ltd, has over 18 years of experience in the telecommunications and networking arena. He is responsible for overall network and data centre management and has been at helm of the company's core and access network infrastructure to support next generation, managed IP services and applications for their global customers.