Q: What are VMotion and
Dynamic Resource Scheduler
(DRS) in VMware?
A: VMware’s ESX software supports VMotion
technology, which allows a running
virtual machine (VM) to be moved between
ESX servers without having to stop the
virtual instance and without the VM missing
a beat in terms of traffic.
DRS uses VMotion capabilities to allow
multiple physical ESX servers to be
grouped as one resource pool of memory
and CPU. This allows virtual instances
within a DRS cluster to be dynamically
moved between the members of the DRS
cluster to balance resource usage with
no downtime to the virtual instances.
The level of automation of the movement
between servers depends on the
automation level selected (which allows
only suggestions for where to move virtual
instances): Partially Automated moves
virtual instances only at power-on time,
and Fully Automated automatically moves
virtual instances according to a selected
threshold (based on the move’s recommendation
level).