What is Hyper‑V enhanced session mode?
Well, this is simply the capability of accessing your Hyper‑V host,
that is,
the server that's running the Hyper‑V hypervisor, and which is hosting
one or more virtual machines. And you can access from the perspective
of the VM the Hyper‑V host's resources.
Maybe you need to RDP into a VM and pull files from the host's file
system. Or maybe you want to use the clipboard,
the Windows clipboard, to copy and paste text or even binary
data between the host and the virtual machine.
That's what enhanced session mode is.
You can mount fixed and removable disks from the host inside the VM.
You can connect and print to printers that are connected to the hardware host.
The limitation to enhanced session mode is that you have to use the
VMConnect tool. You can't use another RDP client.
You have to use the Hyper‑V one.
Now, the good news is that we get VMConnect when you do an RSAT
installation on Windows Client, so you will have it. And you can see in
the connection flow there's local devices and resources,
printer and clipboard, and if you click More, you can hook up to
smart cards and other plug‑and‑play devices.
Now with regard to Hyper‑V via memory, there is the concept of dynamic memory.
Now this is, well, first of all, to take a step back,
remember that when we create a virtual machine, we allocate it virtual
resources that are actually coming from the Hyper‑V host.
So if your Hyper‑V host has 32 GB of RAM.
and then you're going to have N number of VMs,
you're going to need to be careful about allocating RAM to
the VMs to conserve RAM on the host.
Dynamic memory allows you to specify a range that Hyper‑V host will
choose dynamically as the VM is doing its work.
It's a more efficient way to allocate host memory to VMs.
Monitoring is something you should do anyway,
but you'll want to monitor your VMs to set in the Hyper‑V
memory settings a buffer percentage.
In other words,
how much of the allocated RAM that you've given to the VM
should it always hold onto as a buffer? Again,
you need to answer that question, and the way to do
that is monitoring utilization,
which you can do from the perspective of the Hyper‑V host or from the guest OS
and the VM. You can implement quality of service in Hyper‑V in a number of ways,
and quality of service simply means where you have VMs that may need dedicated
extra capabilities or extra resources.
So you can specify a memory weight percentage as well to
prioritize host RAM allocation to certain VMs.
Again,
monitoring, you'll want to monitor in your VMs and the apps that are
running on those VMs to guard against memory leaks.
You want to make sure that you've got good alignment between the VM host
and the virtual machine guests. We've got Hyper‑V integration services
that you'll want to enable and keep up to date.
And lastly,
there is the question, maybe dynamic memory isn't a
good fit for a particular VM.
It's not a one‑size‑fits‑all.
You may have a VM that's operating as a mail server or a database server where
you want to give it a fixed amount of RAM, and that's it.
The VM should have 100% of that RAM allocation 100% of the time. Again, you answer these questions through monitoring.