Get The Pros of Virtualization Without the Cons
From the start of this part on ESXi and type 1 hypervisors, we have only looked at small-scale architecture for which this virtualization solution is not suited.
This is because the architecture we have focused on only had two machines to virtualize.
However, there are several points to remember when you want to virtualize fewer than five machines (of course, this number is not set in stone):
The financial benefit of virtualization at this scale does not apply to saving on hardware costs.
The energy savings are also quite low.
It can save on physical space (minimally), as servers are now designed to be stored in racks.
There is a loss of redundancy, and you are less resistant to outages as servers will be on the same physical machine.
IT professionals can’t afford to take this type of risk, which is why you need to think about your architecture to make sure it’s redundant before trying to virtualize everything.
Analyze the Functions of a Multi-ESXi Architecture
Deploying several ESXi hosts can benefit an organization significantly. Here is a list of some essential functions related to multi-ESXi architecture which all good network/Cloud engineers should know:
Function | Description | Use | VMware name |
VM migration | Move a VM from one ESXi to another. This operation can be carried out “cold” (with the VM switched off) or “hot” (with the VM switched on) without interrupting service. |
| vMotion |
Load balancing | Set load limits that cannot be exceeded on an ESXi and launch VM migration when the limit is reached |
| DRS |
High availability | Monitor several ESXis Launch migration of all VMs from an ESXi if it stops functioning |
| HA |
Backup (possible with a single ESXi) | Create a copy of your VM at a given moment in time |
| Snapshot |
Implement a Multi-ESXi Architecture
If you go back to the architecture from the previous chapter and add an ESXi with an Authentication server VM and a Print server VM, this is what you end up with.
They also need to be put on the same network to make VM migration possible.
How can ESXis migrate their VMs from one to another when they don’t know their capacities or names?
Good question. To migrate, you have to put the ESXis in the same cluster and on the same network. To create an ESXi cluster, you need a vCenter Server.
vCenter is an app that allows you to manage an ESXi (as we did with vSphere Web Client) and provides access to the many functions of these ESXi clusters.
There are two ways of installing vCenter:
On a Windows Server physical machine (legacy method).
On a VM based on Linux called VCSA (new method).
The second method might seem strange, as vCenter will be on a VM from the ESXi cluster, which manages the ESXi cluster itself. Still, it’s much more practical than the first method, which requires a Windows Server machine and license.
In any case, with new versions of vSphere, you won’t have a choice and will have to install vCenter via VCSA (vCenter Server Appliance).
The architecture will look like this:
After you’ve done this, you’ll be able to try out the full range of vSphere functions. VM migration, for example, will take place via a communication network between the ESXis.
There’s enough to learn about using vSphere and vCenter in business architecture for a whole other course, so we won’t go into detail here.
Type 1 Hypervisors for Business Architecture
You now have a good overview of what type 1 hypervisors such as ESXi and its vSphere suite offer and how they differ from type 2 hypervisors.
Type 1 hypervisors can fully replace physical architecture, making it robust, resilient, resistantto outages, and save on hardware and energy consumption. This type of virtualization solution is now widely used in companies and is transparent for users. You will likely come across them if you work as a cloud network engineer or similar.
You’re now ready to deal with situations where virtualization solutions are already in place, or even deploy one yourself if you think it could be beneficial.
Let’s Recap!
There are several considerations when virtualizing machines on a small scale:
The financial benefit
Energy savings
Physical space
Redundancy
Multi-ESXi architecture can add many benefits, including:
VM migration
Load balancing
High availability
Backups
To build a completely private network between the VMs, create a new vSwitch that isn’t linked to a physical network interface.
To make migration between servers possible, you need to create an ESXi cluster using vCenter Server.
vCenter adds additional functionality to your environment and allows you to manage ESXi as we did with the vSphere web client.
You have made it to the end of the final chapter!
That’s everything for this course! Take our final quiz to make sure that you are ready to use type 1 hypervisors in your projects. Thanks for joining me, and I hope you have enjoyed the course as much as I have creating it. See you next time on OpenClassrooms!
