Virtualization Abstracts the Hardware Layer

One of the great features of virtualization is the ability to abstract the operating system and the applications from the underlying hardware.  A virtual machine (VM) is a software machine that runs an operating system and its environment.  By running an operating system and its applications inside of a software machine instead of a physical machine provides a lot of flexibility and speed in deploying operating systems and applications.

Features in VMware software that leverage hardware abstraction include:

• vMotion - ability to move a VM and its environment live to another physical host without any down time.  
• vCenter Converter - ability to move the operating system and environment from a physical machine to a virtual machine running on a different host. 
• HA - High availability can start up a VM on a different physical server after its original server fails.
• Distributed Resource Scheduler (DRS) - Ability to load balance VMs and make decisions when to move a VM from one host to another with no down time.
• DRS Cluster - VMs can be spread across multiple host servers.  So operating systems and their applications become completely independent of the hardware they run on.  
• Distributed Power Management (DPM) - Ability to move VMs from one host to another and power down host servers that are not being utilized and then powering the host servers back up when there is sufficient utilization.
• Fault Tolerance (FT) - Ability to mirror VM on a separate host, so if the original environment goes down, then the mirrored environment becomes the primary and a new secondary environment is created.

Treating host servers, VMs and Virtual Appliances (multiple VMs running together) as software components in a virtualized data center allows:

• VMs and their applications to be moved transparently to different host servers.  This not only abstracts the hardware  from VMs (operating systems and their applications) but even what hardware VMs run on.