Virtualization has been one of the hottest buzzwords in the
IT circle for quite some time now. Out of the three types of virtualization that
are possible (server, network and storage), server virtualization saw a lot of
action last year. Simply speaking, the technology allows you to run multiple OSs
on the same physical hardware simultaneously. It could either be based on
hardware partitioning, wherein each OS sees its own dedicated hardware, viz CPU,
RAM, HDD, BIOS, I/O devices, etc; or it could be based on OS partitioning,
wherein the virtualization layer will run multiple threads of the same OS as the
base OS. Virtualization technology has many benefits, which really make it worth
considering. One is that it reduces the clutter of servers in your data center.
So instead of having a separate physical server for your database, file serving,
Web and other applications, you'll have a single server that runs all of them,
but in their own 'virtual' domains. One immediate interpretation of this is
that you'll need very powerful hardware to be able to do this. Yes, the
hardware specs do go up, but that doesn't mean you need a supercomputer for
it. You would need additional storage capacity for all the OSs and their
applications. You'll also need to provide the recommended RAM requirements for
each application. But you could use the same processor(s). The reason for this
is simple. Take an existing scenario of having different physical servers for
each application. Here, it's not as if each server's computing power will be
utilized 100% all the time. There would be times when they'll be idle, times
when they'd be moderately used and times when they'll undergo peak
utilization. If you combine just the idle time of all the servers in your data
center, then you'll discover a huge amount of unutilized capacity sitting in
your data center, all going waste. With virtualization, multiple applications
will run on the same physical server. By and large, it's unlikely that
they'll be utilized to the maximum all the time. Some would peak at one time,
while others would peak at other times. So the average utilization of the
physical server will go up, thereby reducing the wasted capacity.
Virtualization technology offers a lot of business
benefits, which definitely make it a worthy candidate to consider for your data
center. Since it reduces the number of servers, it saves a lot of precious floor
space in the data center. Since servers have to be up 24x7, having fewer servers
means lesser power consumption and air-conditioning requirements. This
translates to direct cost saving in electricity bills. Virtualization also leads
to lesser administrative overheads, as more servers can be controlled from a
single console. It also helps you roll out new servers more quickly, as all
you'd be doing is replicating copies of your virtual machines, which is much
faster than setting up a fresh server and loading everything from scratch. This
also helps in testing applications for patches, updates, and upgrades before
rolling them out. Data centers aren't the only beneficiaries of
virtualization. It's also useful for developers, who need to test all their
code. Instead of testing on their base OS, they could do it on a virtual
machine, and reduce downtime. It could also be used by consultants for
demonstrating their solutions to clients.
While virtualization can lead to lots of business benefits
and help you consolidate your data center, it requires careful planning while
deploying. For one, since multiple applications are running on the same physical
hardware, downtime can be disastrous. If the physical server goes down, all your
applications would go down. Earlier, it would only have been a single
application going down. So, you would need to plan for some redundancy, perhaps
a fail-over server. Likewise, all virtual machines would need close monitoring.
It shouldn't happen that one of them hogs up all the resources, leaving others
hunting for compute cycles. The virtualized environment has to be design very
carefully, and tuned for performance. Migration to a virtual environment isn't
easy either, especially if you have your own home-grown applications running in
your existing environment. These would be tuned for the existing hardware, and
would require considerable development effort if migrated to a virtual
environment.
So is virtualization here to stay? Absolutely. You'll see
lots of action in this space in the coming year. Currently, most of the action
is in the virtualization software domain, with both commercial and open-source
solutions available. In hardware virtualization, IBM has been the oldest player,
offering the technology on its servers based on the Power5 processor. But now,
virtualization is going to come down to the desktop level pretty soon, with both
Intel and AMD introducing the technology into their own processors. This will
make virtualization cheaper as well, as more virtualization applications are
developed on these platforms. It will also result in stiffer competition for
existing players, thereby making the technology more affordable.
Anil Chopra, Associate Editor