how Hyper-V handles processor allocation compared to a hypervisor such as ESX. This
can make a difference in how you allocate resources. When converting from ESX, you
can match the hardware exactly or you can take the migration as a chance to optimize
the resource allocation or increase it if required. With Hyper-V, there is no penalty to
having additional virtual processors in a virtual machine, and therefore you may
choose to be more generous than with ESX. While it’s important to be accurate in
your planning for migrations to ensure that the right hardware is procured, quite a lot
of flexibility is available, even for a running virtual machine:
Processor While processors cannot be hot-added to a virtual machine, the limits
and weightings can be changed while the virtual machine is running. This is why
potentially having additional virtual processors is a good idea.
Memory With Dynamic Memory, a virtual machine can have additional memory
added as required, and the settings for the memory can be changed while the VM is
running, allowing the maximum to be increased.
Network If bandwidth management is used, the minimum and maximum
bandwidth limits can be modified, and at the host level, it’s possible to add
network adapters to a team to increase available bandwidth.
Storage Additional virtual hard disks can be added to the SCSI controller, and
with Windows Server 2012 R2, a VHDX file attached to the SCSI controller can also
be dynamically expanded.