IBM AIX
AIX is a series of proprietary Unix operating systems developed and sold by IBM since 1986. The name stands for "Advanced Interactive eXecutive". Current versions are designed to work with Power ISA based server and workstation computers such as IBM's Power line.
Background
Originally released for the IBM RT PC RISC workstation in 1986, AIX has supported a wide range of hardware platforms, including the IBM RS/6000 series and later Power and PowerPC-based systems, IBM System i, System/370 mainframes, PS/2 personal computers, and the Apple Network Server. Currently, it is supported on IBM Power Systems alongside IBM i and Linux.AIX is based on UNIX System V with 4.3BSD-compatible extensions. It is certified to the UNIX 03 and UNIX V7 specifications of the Single UNIX Specification, beginning with AIX versions 5.3 and 7.2 TL5, respectively. Older versions were certified to the UNIX 95 and UNIX 98 specifications.
AIX was the first operating system to implement a journaling file system. IBM has continuously enhanced the software with features such as processor, disk, and network virtualization, dynamic hardware resource allocation, and reliability engineering concepts derived from its mainframe designs.
History
Unix began in the early 1970s at AT&T's Bell Labs research center, running on DEC minicomputers. By 1976, the operating system was used in various academic institutions, including Princeton University, where Tom Lyon and others ported it to the S/370 to run as a guest OS under VM/370. This port became Amdahl UTS from IBM's mainframe rival, which that company increasingly prioritized from the late 1980s.IBM's involvement with Unix began in 1979 when it assisted Bell Labs in porting Unix to the S/370 platform to be used as a build host for the 5ESS switch's software. During this process, IBM made modifications to the TSS/370 Resident Supervisor to better support Unix.
In 1984, IBM introduced its own Unix variant for the S/370 platform called VM/IX, developed by Interactive Systems Corporation using Unix System III. However, VM/IX was only available as a PRPQ and was not a General Availability product.
By 1985 most computer companies offered Unix alongside their proprietary operating systems. Although an industry analyst that year described IBM as not enthusiastic about Unix, the company replaced VM/IX in 1985 with IBM IX/370, a fully supported product based on AT&T's Unix System V, intended to compete against UTS and also developed by ISC.
ISC also developed AIX for the IBM RT PC workstation, introduced in January 1986, based on UNIX System V Releases 1 and 2, and incorporating source code from 4.2 and 4.3 BSD UNIX. AIX Version 2 followed in 1987 for the RT PC. AIX was also available for the IBM PC AT and IBM PC XT/286.
In 1990, AIX Version 3 was released for the new POWER-based RS/6000 platform. Observers said that year that IBM had officially approved Unix, with the company willing to let its proprietary AS/400 and Unix-based RS/6000 compete against each other in the midrange system market. AIX was the primary operating system for the RS/6000 series, which was later renamed IBM eServer pSeries, IBM System p, and finally IBM Power Systems.
AIX Version 4, introduced in 1994, added symmetric multiprocessing and evolved through the 1990s, culminating with AIX 4.3.3 in 1999. A modified version of Version 4.1 was also used as the standard OS for the Apple Network Server line by Apple Computer.
In the late 1990s, under Project Monterey, IBM and the Santa Cruz Operation attempted to integrate AIX and UnixWare into a multiplatform Unix for Intel IA-64 architecture. The project was discontinued in 2002 after limited commercial success.
In 2003, the SCO Group filed a lawsuit against IBM, alleging misappropriation of UNIX System V source code in AIX. The case was resolved in 2010 when a jury ruled that Novell owned the rights to Unix, not SCO.
AIX 6 was announced in May 2007 and became generally available on November 9, 2007. Key features included role-based access control, workload partitions, and Live Partition Mobility.
AIX 7.1 was released in September 2010 with enhancements such as Cluster Aware AIX and support for large-scale memory and real-time application requirements.
Supported hardware platforms
IBM RT PC
The original AIX.One of the novel aspects of the RT design is the use of a microkernel, called Virtual Resource Manager. The keyboard, mouse, display, disk drives and network are all controlled by a microkernel. One can "hotkey" from one operating system to the next using the Alt-Tab key combination. Each OS in turn gets possession of the keyboard, mouse and display. Besides AIX v2, the PICK OS also includes this microkernel.
Much of the AIX v2 kernel was written in the PL.8 programming language, which proved troublesome during the migration to AIX v3. AIX v2 includes full TCP/IP networking, as well as SNA and two networking file systems: NFS, licensed from Sun Microsystems, and Distributed Services. DS has the distinction of being built on top of SNA, and thereby being fully compatible with DS on and on midrange systems running OS/400 through IBM i. For the graphical user interfaces, AIX v2 comes with the X10R3 and later the X10R4 and X11 versions of the X Window System from MIT, with the Athena widget set. Compilers for Fortran and C were available.
IBM PS/2 series
AIX PS/2 was developed by Locus Computing Corporation under contract to IBM. AIX PS/2, first released in October 1988, runs on IBM PS/2 personal computers with Intel 386 and compatible processors.The product was announced in September 1988 with a baseline tag price of $595, although some utilities, such as UUCP, were included in a separate Extension package priced at $250. nroff and troff for AIX were also sold separately in a Text Formatting System package priced at $200. The TCP/IP stack for AIX PS/2 retailed for another $300. The X Window System package was priced at $195, and has a graphical environment called the AIXwindows Desktop, based on IXI's X.desktop. The C and FORTRAN compilers each had a price tag of $275. Locus also made available their DOS Merge virtual machine environment for AIX, which can run MS DOS 3.3 applications inside AIX; DOS Merge was sold separately for another $250. IBM also offered a $150 AIX PS/2 DOS Server Program, which provided file server and print server services for client computers running PC DOS 3.3.
The last version of PS/2 AIX is 1.3. It was released in 1992 and announced to add support for non-IBM computers as well. Support for PS/2 AIX ended in March 1995.
IBM mainframes
In 1988, IBM announced AIX/370, also developed by Locus. AIX/370 was IBM's fourth attempt to offer Unix-like functionality for their mainframe line, specifically the System/370. AIX/370 was released in 1990 with functional equivalence to System V Release 2 and 4.3BSD as well as IBM enhancements. With the introduction of the ESA/390 architecture, AIX/370 was replaced by AIX/ESA in 1991 based on OSF/1, and also runs on the System/390 platform. Unlike AIX/370, AIX/ESA runs both natively as the host operating system, and as a guest under VM. AIX/ESA, while technically advanced, had little commercial success, partially because UNIX functionality was added as an option to the existing mainframe operating system, MVS, as MVS/ESA SP Version 4 Release 3 OpenEdition in 1994, and continued as an integral part of MVS/ESA SP Version 5, OS/390 and z/OS, with the name eventually changing from OpenEdition to Unix System Services. IBM also provided OpenEdition in VM/ESA Version 2 through z/VM.IA-64 systems
As part of Project Monterey, IBM released a beta test version of AIX 5L for the IA-64 architecture in 2001, but this never became an official product due to lack of interest.Apple Network Servers
The Apple Network Server systems are PowerPC-based systems designed by Apple Computer to have numerous high-end features that contemporary standard Apple hardware does not have, including swappable hard drives, redundant power supplies, and external monitoring capability. These systems are more or less based on the Power Macintosh hardware available at the time but designed to use AIX as their native operating system in a specialized version specific to the ANS called AIX for Apple Network Servers.AIX is only compatible with the Network Servers and was not ported to standard Power Macintosh hardware. It should not be confused with A/UX, Apple's earlier version of Unix for 68k-based Macintoshes.
POWER ISA/PowerPC/Power ISA-based systems
The release of AIX version 3 coincided with the announcement of the first POWER1-based IBM RS/6000 models in 1990.AIX v3 innovated in several ways on the software side. It is the first operating system to introduce the idea of a journaling file system, JFS, which allows for fast boot times by avoiding the need to ensure the consistency of the file systems on disks on every reboot. Another innovation is shared libraries which avoid the need for static linking from an application to the libraries it used. The resulting smaller binaries use less of the hardware RAM to run, and used less disk space to install. Besides improving performance, executable binaries can be in the tens of kilobytes instead of a megabyte for an executable statically linked to the C library. AIX v3 also scrapped the microkernel of AIX v2, a contentious move that resulted in v3 containing no PL.8 code and being somewhat more "pure" than v2.
Other notable subsystems include:
- IRIS GL, a 3D rendering library, the progenitor of OpenGL. IRIS GL was licensed by IBM from SGI in 1987, a small company, which had sold only a few thousand machines at the time. SGI also provided the low-end graphics card for the RS/6000, capable of drawing 20,000 gouraud-shaded triangles per second. The high-end graphics card was designed by IBM, a follow-on to the mainframe-attached IBM 5080, capable of rendering 990,000 vectors per second.
- PHIGS, another 3D rendering API, popular in automotive CAD/CAM circles, and at the core of CATIA.
- Full implementation of version 11 of the X Window System, together with Motif as the recommended widget toolkit and window manager.
- Network file systems: NFS from Sun; AFS, the Andrew File System; and DFS, the Distributed File System.
- NCS, the Network Computing System, licensed from Apollo Computer.
- DPS on-screen display system as an alternative if the X11+Motif combination failed in the marketplace. However, it is highly proprietary, supported only by Sun, NeXT, and IBM. This, and lack of 3D capability, caused it to fail in the marketplace versus X11+Motif and its lack of 3D capability.