Enter virtualization, with virtualization hypervisors can run multiple applications concurrently and sometimes simultaneously on the same hardware server without compromising application execution integrity. Multiple virtual machine applications execute on a single server under a hypervisor that isolates the applications from one another. Thus, they all execute together on the same hardware without impacting each other.
But why doesn’t the O/S do this?
Most computer purists would say why not just run the multiple applications under the same operating system. But operating systems that run servers nowadays weren’t designed to run multiple applications together and as such, also weren’t designed to isolate them properly.
Virtualization hypervisors have had a clean slate to execute and isolate multiple application. Thus, virtualization is taking over the data center floor. As new servers come in, old servers are retired and the applications that used to run on them are consolidated on fewer and fewer physical servers.
Why now?
Current hardware trends dictate that each new generation of server has more processing power and oftentimes, more processing elements than previous generations. Today’s applications are getting more sophisticated but even with added sophistication, they do not come close to taking advantage of all the processing power now available. Hence, virtualization wins.
What seems to be happening nowadays is that while data centers started out consolidating tier 3 applications through virtualization, now they are starting to consolidate tier 2 applications and tier 1 apps are not far down this path. But, tier 2 and 1 applications require more dedicated services, more processing power, more deterministic execution times and thus, require more sophisticated virtualization hypervisors.
As such, VMware and others are responding by providing more hypervisor sophistication, e.g., more ways to dedicate and split up processing, networking and storage available to the physical server for virtual machine or application dedicated use. Thus preparing themselves for a point in the not to distant future when tier 1 applications run with all the comforts of a dedicated server environment but actually execute with other VMs in a single physical server.
VMware vSphere
We can see the start of this trend with the latest offering from VMware, vSphere. This product now supports more processing hardware, more networking options and stronger storage support. vSphere also can dedicate more processing elements to virtual machines. Such new features make it easier to support tier 2 today and tier 1 applications sometime in future.