- Server and network virtualization
have been with us for quite a while now.
But I still run across people that are new to the idea.
The basic concept is this.
A very low level application is installed
on a server, and it makes an inventory
of physical hardware to assess
how that hardware can be offered up to simulate
multiple isolated machines.
It can then assign virtual processors
and portions of physical RAM,
as well as simulated network and storage controllers,
and bundle all these resources together
in a single file that is the virtual machine.
Then, one or more files are created
that emulate hard drives.
This allows you to open up a virtual machine
consisting of only two or three files.
One representing the resources available,
and one or more representing the hard drives
that store the data.
This will allow you to more completely utilize
all of the hardware available in high power servers.
And, configured correctly, it can allow you
to keep a server online, even when some
hardware issues may occur.
There are several major players in the virtualization space.
Each with their own strengths and weaknesses.
Hyper-V is Microsoft's virtualization platform.
And it's been around since Windows Server 2008,
and on Professional and Enterprise
work stations since Windows8.
And some of the features that we've already discussed
have had an impact on Hyper-V on Windows 2019 servers.
The addition of data deduplication in ReFS
means virtual hard drives can now be stored
on those volumes in a way that is not only faster
and more resilient, but now also more efficient as well.
The improvements made to Storage Replica
and Storage Spaces Direct allow separate
physical hosts to maintain synchronized copies
of the virtual hard drive, which can allow
for zero downtime, even if an entire data center
goes dark unexpectedly.
But Hyper-V does have a few limitations.
More so in earlier releases.
On Windows work stations, the virtualization
environment has created some conflicts
when watching high resolution video
through common third party software.
This is still the case on current versions
but that shouldn't be a problem when configuring a server.
The biggest limitation was that Hyper-V
was designed to host Windows servers,
and had little consideration for anything else.
The virtualized hardware was easy enough to understand,
but none of the features that make servers resilient
and protected worked on Linux environments.
Virtualizing Mac environments is still a challenge
because of the way Apple licenses their product.
But Linux is a different story.
Linux servers are growing in popularity,
and in Windows server 2019, Microsoft has made
some noteworthy steps to accommodate Linux
guest machines on Hyper-V hosts.
One of the features, previously not available
to Linux guest machines, was the server 2016 feature
of shielded virtual machines,
and the host guardian server.
Going forward, we're going to take a look
at how that's been expanded to include
this new market.