Mainframes share a lot of similarities with cloud data centres. Redundant hot swappable components (even the CPUs in some models). Virtualised operating syste

Mainframes share a lot of similarities with cloud data centres. Redundant hot swappable components (even the CPUs in some models). Virtualised operating systems (VMs were invented for mainframes). These days it wouldn’t be unusual for some mainframes to be running mostly Linux instances. You could almost think of a mainframe as a cloud in a box, and if one isn’t realiable enough, you can always run two or more.