Database Reference
In-Depth Information
available platform on which to run your enterprise applications. We will now discuss
features within vSphere that provide high availability to the virtual machines that run on
top of vSphere.
Hypervisor Availability Features
The hypervisor itself has been built and designed to provide performance and
protection. Many features exist within vSphere that make vSphere the platform on which
to run your most demanding applications. For example, what happens when one virtual
machine—say, a test/development virtual machine—begins to consume precious I/O on
the array and begins to interfere with the production SQL Server virtual machine on the
same host? Storage I/O control kicks in and ensures the production SQL Server receives
the proper I/O distribution.
What makes vSphere the desired platform on which to run your applications is
VMware's core philosophy on the virtualization, which is evident in the products and
solutions they provide customers. The four core tenants are as follows:
Partitioning
Isolation
Encapsulation
Hardware independence
Partitioning is defined as the ability to run multiple operating systems on one physical
device and provide a means by which this device's physical resources are divided
among the virtual machines resident on this device.
Isolation is defined as providing fault and security isolation at the hardware level while
providing advanced resource controls to ensure availability and performance of the
virtual machine running on the physical hardware. This is the “one virtual machine blue
screen does not affect other running virtual machines on the same host” philosophy.
Encapsulation is the ability to save an entire virtual machine's system state into a set of
files. We have all been working with files for many years, so we understand how to
copy and paste files. How much easier is disaster recovery if we are copying files
versus ensuring firmware versions are identical on each server.
Hardware independence is the philosophy that administrators should be able to
provision or migrate a virtual machine to any similar or different piece of physical
hardware. The ability to pry a vendor's label off the physical asset and to seamlessly
slide in the right solution from the right vendor is a strong value proposition. For the
DBAs, this is the “I can move my database to the new, shiny, and more powerful server
every time it is added to the cluster versus running SQL on the same piece of hardware
for five years” feature.
Moving past philosophy and into the hypervisor itself, there are features present within
