Integrated Facility for Linux
Encyclopedia
The Integrated Facility for Linux (IFL) is an IBM mainframe
processor dedicated to running the Linux
operating system, with or without z/VM
. IFLs are one of three types of IBM mainframe processors expressly designed to reduce software costs. (The other types are zAAP for Java code and zIIP
for DB2.) Microcode
restricts IFLs to Linux workload by omitting some processor instructions not used by the Linux kernel. As with zAAPs and zIIP
s, IFLs are not specifically optimized to run Linux
faster or better.
IBM introduced IFLs 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 discontinued S/390 Virtual Image Facility for Linux in April 2002.
Potential customers can purchase IFLs for all IBM mainframes as far back as the G5 series. Fujitsu
and Hitachi
also offered IFLs on certain models. An IFL is not required to run Linux — Linux runs on general purpose processors (CPs) as well. IFLs simply cost less.
processors. (Ivory Server also provides support for zIIP
and zAAP.)
IBM mainframe
IBM mainframes are large computer systems produced by IBM from 1952 to the present. During the 1960s and 1970s, the term mainframe computer was almost synonymous with IBM products due to their marketshare...
processor dedicated to running the Linux
Linux
Linux is a Unix-like computer operating system assembled under the model of free and open source software development and distribution. The defining component of any Linux system is the Linux kernel, an operating system kernel first released October 5, 1991 by Linus Torvalds...
operating system, with or without z/VM
VM (operating system)
VM refers to a family of IBM virtual machine operating systems used on IBM mainframes System/370, System/390, zSeries, System z and compatible systems, including the Hercules emulator for personal computers. The first version, released in 1972, was VM/370, or officially Virtual Machine Facility/370...
. IFLs are one of three types of IBM mainframe processors expressly designed to reduce software costs. (The other types are zAAP for Java code and zIIP
ZIIP
In IBM System z9 mainframes, the System z Integrated Information Processor is a special purpose processor. It was initially introduced to relieve the general mainframe central processors of specific DB2 processing loads, but currently is used to offload other z/OS workloads as described below...
for DB2.) Microcode
Microcode
Microcode is a layer of hardware-level instructions and/or data structures involved in the implementation of higher level machine code instructions in many computers and other processors; it resides in special high-speed memory and translates machine instructions into sequences of detailed...
restricts IFLs to Linux workload by omitting some processor instructions not used by the Linux kernel. As with zAAPs and zIIP
ZIIP
In IBM System z9 mainframes, the System z Integrated Information Processor is a special purpose processor. It was initially introduced to relieve the general mainframe central processors of specific DB2 processing loads, but currently is used to offload other z/OS workloads as described below...
s, IFLs are not specifically optimized to run Linux
Linux
Linux is a Unix-like computer operating system assembled under the model of free and open source software development and distribution. The defining component of any Linux system is the Linux kernel, an operating system kernel first released October 5, 1991 by Linus Torvalds...
faster or better.
IBM introduced IFLs 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
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, with IBM's CP/CMS on the IBM System/360-67...
was not too difficult for new IT staff to learn (and worked better), so IBM discontinued S/390 Virtual Image Facility for Linux in April 2002.
Potential customers can purchase IFLs for all IBM mainframes as far back as the G5 series. Fujitsu
Fujitsu
is a Japanese multinational information technology equipment and services company headquartered in Tokyo, Japan. It is the world's third-largest IT services provider measured by revenues....
and Hitachi
Hitachi, Ltd.
is a Japanese multinational conglomerate headquartered in Marunouchi 1-chome, Chiyoda, Tokyo, Japan. The company is the parent of the Hitachi Group as part of the larger DKB Group companies...
also offered IFLs on certain models. An IFL is not required to run Linux — Linux runs on general purpose processors (CPs) as well. IFLs simply cost less.
Support for IFL
Ivory Server for z/Linux from GT Software, Inc. provides support for IFLIFL
IFL may refer to:*Interflug, an extinct airline that used the ICAO code IFL*International Fight League, a former American mixed martial arts league*Imperial Fascist League*Imperial Federation League*Indonesian Futsal League*Indoor Football League...
processors. (Ivory Server also provides support for zIIP
ZIIP
In IBM System z9 mainframes, the System z Integrated Information Processor is a special purpose processor. It was initially introduced to relieve the general mainframe central processors of specific DB2 processing loads, but currently is used to offload other z/OS workloads as described below...
and zAAP.)