Chapter 2: Virtual Machine Resource Fundamentals
Describe how the resources of a virtual machine are virtualized by the
hypervisor. The hypervisor directly manages the processor and memory resources
with Hyper-V. Logical processors are scheduled to satisfy computer requirements of
virtual processors assigned to virtual machines. Multiple virtual processors can share
the same logical processor. Virtual machines are assigned memory by the hypervisor
from the memory available in the physical host. Dynamic Memory allows memory to
be added and removed from a virtual machine based on resource need. Other types of
resources, such as network and storage, are provided by the management partition
through a kernel mode memory bus known as a VMBus. This allows existing Windows
drivers to be used for the wide array of storage and network devices typically used.
Master It How is Dynamic Memory different from Memory Overcommit?
Solution Dynamic Memory allocates memory in an intelligent fashion to virtual
machines based on how it is being used by processes running inside the virtual
machine. Memory Overcommit technologies work by telling a virtual machine that
it has a large amount of memory and allocating the memory only as the virtual
machine writes to it. However, this approach does not work well with modern
operating systems that try to use all memory available, even if it’s only for cache
purposes.Correctly use processor and memory advanced configuration options. The
compatibility configuration of a virtual machine processor should be used when a
virtual machine may be moved between hosts with different versions of the same
processor family. The processor compatibility option hides higher-level features from
the guest operating system, enabling migrations without downtime to the virtual
machine. Processor reserve and limit options ensure that a virtual machine coexists
with other virtual machines without getting too many or too few resources. Dynamic
Memory configurations allow the startup, minimum, and maximum amounts of
memory for a virtual machine to be configured. It’s important to note that the
maximum amount of memory configured is available only if sufficient memory exists
within the host.
Master It When should the NUMA properties of a virtual machine be modified?
Solution Hyper-V will configure the optimal settings for virtual machines based
on the physical NUMA configuration of the hosts. However, if a virtual machine
will be moved between hosts with different NUMA configurations, then the NUMA
configuration of the virtual machine should be changed to match the smallest
NUMA configuration of all of the hosts it may be moved between.Explain the difference between VHD/VHDX and pass-through storage. VHD
and VHDX files are virtual hard disks that are files on a filesystem or share accessible
to the Hyper-V host. They provide abstraction of the storage seen by the virtual