The Ghan of Australia. "The Ghan" service was notorious for delays caused by washouts of the track. A flatcar immediately behind the locomotive carried spare sleepers and railway tools, so passengers and crew could repair the line. The very uncertain service via this route was tolerated because steam locomotives needed large quantities of water, and Stuart's route to Alice Springs was the only one that had sufficient available water. During World War II the service had to be greatly expanded, putting great pressure on the limited water supplies. As a result, de-mineralisation towers, some of which survive to this day, were built
Infrastructure as a service capacity auto-scales dynamically with computing load, which eliminates the problem of over-provisioning and enables usage-based billing. IaaS clouds often offer additional resources such as a virtual-machine disk-image library, raw block storage, file or object storage, firewalls, load balancers, IP addresses, virtual local area networks (VLANs), and software bundles. The NIST's definition of cloud computing defines Infrastructure as a Service as: According to the Internet Engineering Task Force (IETF), the most basic cloud-service model is that of providers offering IT infrastructure — virtual machines and other resources — as a service to subscribers. IaaS-cloud providers supply these resources on-demand from their