Hardware virtual machines
Hardware virtual machines don't enjoy the bare metal performance of Joyent's container offerings, but they do offer a solution for legacy or specialized applications that can't be run in a containerized environment. Triton offers support for these applications via KVM, but there are some differences between infrastructure containers and hardware virtual machines to be aware of.
Expect hardware virtual machines to be slower than infrastructure containers. Triton's container offerings run on bare metal, without the additional layers of a hardware virtual machine that slow I/O and CPU performance.
Live resizing of KVM instances is not supported. Infrastructure containers can be resized to add memory, CPU, and disk space without rebooting, but the nature of hardware virtualization does not allow that convenience.