An Overview of Bare Metal Virtualization
Let’s start by explaining what the term bare metal refers to:
It’s the physical state of server hardware (aka bare metal) filling server cabinets in most legacy data centers.
Moreover each physical server is running one operating system such as Windows or Linux, and one application (aka platform).
And in most cases bare metal servers are using less than 20% of available system resources (the other 80% is idle).
This may not sound like much but it’s a big problem [or opportunity] when you calculate the cost of each physical server, and then multiply it by how many servers are wasting 80% of their compute power (CPUs and memory).
Now you see the value of bare metal virtualization. But this is only the beginning, there’s much more…
Virtualization and Cloud Computing
I’m going give five very simple answers [at the most basic level] to help understand common questions about virtualization and cloud computing.
Let’s start with…
What is bare metal virtualization?
There are two ways to answer this question:
First, bare metal virtualization means to take the platform running on physical hardware (OS and App), and convert it into a virtual instance of the same platform (aka P2V), which is called a virtual machine (aka VM).
A VM is a full featured working replica of the physical server (application and all).
And secondly, it means to take the physical platform that supports one (OS & App) instance and transform it from a bare metal state into highly efficient compute capacity capable of supporting multiple virtual machines.
This is known as a hypervisor server (aka the host).
So in essence you have one physical server that can now run multiple server instances and utilize 80 – 100% of the compute resources, depending on the CPU and memory configuration.
What is a hypervisor?
A hypervisor is the secret sauce that enables the bare metal virtualization magic to happen. Without going into too much detail, it is a layer between the physical hardware and the virtual machines.
There are several hypervisors available and the best hypervisor to pick really depends on how it will be used. Read more about which is the best virtual machine software.
Common uses for hypervisors:
- Virtualizing Servers – converting physical servers into virtual machines, or deploying Windows or Linux straight to a virtual machine.
- Virtualizing Desktops – Deploying desktop operating systems using VDI technology to allow for remote access to desktops and other BYOD advantages.
- Virtualizing Networks – Similar to virtualization of server hardware but on network hardware.
- Virtualizing Storage – Similar to virtualization of server hardware but on storage hardware.
- Virtualization of Applications – This transforms applications installed on a local device into highly available applications that can be run remotely via a client or VDI.
What is the definition of virtualization?
To define virtualization in easy to understand terms, it’s taking something in a bare metal or physical state such as hardware or applications and transforming it using virtualization technology [hypervisor] into a working virtual instance or replica.
This is the simplest virtualization definition I can come up with and the list of uses I’ve share above is limited. The uses of virtualization technology are growing daily as more ways are found to benefit from it.
Are there Virtualization Pros and Cons?
Yes. There are advantages and disadvantages of virtualization. However the advantages of server virtualization [and other types of virtualization] outweigh the disadvantages.
In cases where there are negative outcomes, it is normally due to trying to virtualize a platform that has certain physical requirements that cannot be replicated, or the resource requirements are 1 to 1 at the hardware level.
The key benefit losses are: platform mobility (aka vMotion) and the elimination of bare metal constraints that create a single point of failure (aka HA).
Another Con is over-leveraging physical resources to the point of poor virtual machine performance. But this can easily be resolved by adding more resources and implementing a plan for capacity management.
Is virtualization in cloud computing?
Most definitely, yes!
Many private clouds are built using VMware vSphere. And there are VMware vSphere alternatives such as Openstack and KVM that are commonly found in the public clouds.
Did you know all the advantages of cloud computing would not be available today if it were not for bare metal virtualization enabling companies like Amazon and Rackspace to build their cloud service?
Virtualization in cloud computing makes this all possible because it would be too expensive to build a cloud running a single OS and application, per physical server instance. Furthermore the concept of elastic would not be possible if platforms were still fixed to hardware.
So you can see how the benefits of bare metal virtualization have made cloud computing possible and there is much more to come…