A mainframe is a high-capacity computer that often serves as the central data repository in an organization’s IT infrastructure. It is linked to users through less powerful devices such as workstations or terminals. Centralizing data in a single mainframe repository makes it easier to manage, update and protect the integrity of the data. Mainframes are generally used for large-scale computer processes that require higher availability and security than smaller-scale machines can provide. For example, the IBM z13 mainframe is capable of processing 2.5 billion transactions per day.
The original mainframes were housed in room-sized metal frames, commonly called “big iron.” In the past, a typical mainframe might have occupied 2,000 to 10,000 square feet. Newer mainframes are the size of a large refrigerator, occupying less than 10 square feet. Some computer manufacturers don’t use the term mainframe, calling any commercial-use computer a server; a “mainframe” is simply the largest type of server. In most cases, mainframe refers to computers that can support thousands of applications and input/output devices simultaneously, serving many thousands of users.
Long past their predicted extinction in 1996, mainframes are the only type of computing hardware that can handle the huge volumes of transactions used in many industries today, including banking, insurance, healthcare, government and retail. According to IBM, 80% of the world’s corporate data is still managed by mainframes. More than a quarter of the mainframe processing capacity that IBM ships is used to run Linux. Mainframes are ideal for server consolidation, where one mainframe can run as many as 100,000 virtual Linux servers. SUSE Linux Enterprise provides support for IBM z System mainframes.