The Integrated Facility for Linux (IFL) is an

IBM mainframe IBM mainframes are large computer systems produced by IBM since 1952. During the 1960s and 1970s, IBM dominated the large computer market. Current mainframe computers in IBM's line of business computers are developments of the basic design of th ...

and Power Systems processor dedicated to running the

Linux Linux ( or ) is a family of open-source Unix-like operating systems based on the Linux kernel, an operating system kernel first released on September 17, 1991, by Linus Torvalds. Linux is typically packaged as a Linux distribution, whi ...

operating system. On

IBM Z IBM Z is a family name used by IBM for all of its z/Architecture mainframe computers. In July 2017, with another generation of products, the official family was changed to IBM Z from IBM z Systems; the IBM Z family now includes the newest mod ...

and IBM LinuxONE machines, IFLs can be used with or without

hypervisors A hypervisor (also known as a virtual machine monitor, VMM, or virtualizer) is a type of computer software, firmware or hardware that creates and runs virtual machines. A computer on which a hypervisor runs one or more virtual machines is cal ...

such as

z/VM z/VM is the current version in IBM's VM family of virtual machine operating systems. z/VM was first released in October 2000 and remains in active use and development . It is directly based on technology and concepts dating back to the 1960s, wi ...

and KVM. IFLs are one of three most common types of "specialty" IBM mainframe processors that give software vendors (and their customers) more granular control over software licensing and maintenance costs. (The other most common specialty processors are and ICFs).

Microcode In processor design, microcode (μcode) is a technique that interposes a layer of computer organization between the central processing unit (CPU) hardware and the programmer-visible instruction set architecture of a computer. Microcode is a la ...

restricts IFLs to Linux workload by omitting some processor instructions not used by the Linux kernel (that other operating systems use), but the underlying processors are physically identical to general purpose processors (CPs). When IBM adds features and performance improvements to its mainframes' general purpose main processors (which can also run Linux), those features and improvements nearly always apply equally to IFLs. In fact, in recent IBM Z machines IFLs support

simultaneous multithreading Simultaneous multithreading (SMT) is a technique for improving the overall efficiency of superscalar CPUs with hardware multithreading. SMT permits multiple independent threads of execution to better use the resources provided by modern proces ...

, a feature not available for general purpose processors. IBM announced IFLs on August 1, 2000, and started shipping them on September 29, 2000. At the same time, IBM introduced a special Linux-only, VM-like product called the S/390 Virtual Image Facility for Linux to cater to IT staff previously unfamiliar with IBM mainframes. IBM soon discovered that z/VM was not too difficult for new IT staff to learn (and worked better), so IBM withdrew S/390 Virtual Image Facility for Linux from marketing on April 30, 2002.IBM U.S. Announcement Letter 901-307. Customers could purchase IFLs for all IBM mainframes as far back as the G5 series and can purchase IFLs for all recent IBM Z and LinuxONE machine models. IFLs also support select IBM software appliances such as the IBM Db2 Analytics Accelerator, zAware, and

z/VSE VSEn (''Virtual Storage Extended'') is an operating system for IBM mainframe computers, the latest one in the DOS/360 lineage, which originated in 1965. DOS/VSE was introduced in 1979 as a successor to DOS/VS; in turn, DOS/VSE was succeeded by ...

Network Appliance, and they also supported the Z port of the now abandoned

OpenSolaris OpenSolaris () is a discontinued open-source computer operating system based on Solaris and created by Sun Microsystems. It was also, perhaps confusingly, the name of a project initiated by Sun to build a developer and user community around t ...

operating system.

Fujitsu is a Japanese multinational information and communications technology equipment and services corporation, established in 1935 and headquartered in Tokyo. Fujitsu is the world's sixth-largest IT services provider by annual revenue, and the la ...

and

Hitachi () is a Japanese multinational conglomerate corporation headquartered in Chiyoda, Tokyo, Japan. It is the parent company of the Hitachi Group (''Hitachi Gurūpu'') and had formed part of the Nissan ''zaibatsu'' and later DKB Group and Fuyo G ...

also offered IFLs on certain models of their machines. On Power Systems IFLs are also specially priced for both the processors and many software products.

External links

IBM IFL

Power IFL

References

{{Reflist IBM mainframe technology Server hardware

See also

External links

References