|Source model||Closed source|
|Latest release||7.1 TL3 / November 19, 2013|
|Marketing target||Workstation, Server|
|Platforms||ROMP, IBM POWER, PowerPC, IBM PS/2, System/370, ESA/390|
|Kernel type||Monolithic with dynamically loadable modules|
|Default user interface||
Common Desktop Environment,
(Plasma Workspaces and GNOME optional)
AIX (Advanced Interactive eXecutive, pronounced ) is a series of proprietary Unix operating systems developed and sold by IBM for several of its computer platforms. Originally released for the IBM 6150 RISC workstation, AIX now supports or has supported a wide variety 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.
AIX is based on UNIX System V with 4.3BSD-compatible extensions. It is one of five commercial operating systems that have versions certified to The Open Group's UNIX 03 standard (the others being Mac OS X, Solaris, Inspur K-UX and HP-UX).
The AIX family of operating systems debuted in 1986, became the standard operating system for the RS/6000 series on its launch in 1990, and is still actively developed by IBM. It is currently supported on IBM Power Systems alongside IBM i and Linux.
AIX was the first operating system to utilize journaling file systems, and IBM has continuously enhanced the software with features like processor, disk and network virtualization, dynamic hardware resource allocation (including fractional processor units), and reliability engineering ported from its mainframe designs.
- History 1
Supported hardware platforms 2
- IBM 6150 RT 2.1
- IBM PS/2 series 2.2
- IBM mainframes 2.3
POWER/PowerPC-based systems 2.4
- POWER7 AIX features 2.4.1
- Apple Network Servers 2.4.2
- IA-64 systems 2.5
- POWER/PowerPC releases 3.1
- IBM PS/2 releases 3.2
- IBM 6150 RT releases 3.3
User interfaces 4
- Graphical 4.1
- System Management Interface Tool 4.2
- See also 5
- References 6
- External links 7
Unix started life at AT&T's Bell Labs research center in the early 1970s, running on DEC minicomputers. By 1976, the operating system was in use at various academic institutions, including Princeton, where Tom Lyon and others ported it to the S/370, to run as a guest OS under VM/370. This port would later grow out to become UTS, a mainframe Unix offering by IBM's competitor Amdahl Corporation. IBM's own involvement in Unix can be dated to 1979, when it assisted Bell Labs in doing its own Unix port to the 370 (to be used as a build host for the 5ESS switch's software), making modifications to the TSS/370 hypervisor.
It took until 1985 for IBM to offer its own Unix on the platform: IX/370, developed by Interactive Systems Corporation and designed to compete with Amdahl UTS. The operating system offered special facilities for interoperating with PC/IX, Interactive/IBM's version of Unix for IBM PC compatible hardware, with licenses costing $10,000 per sixteen concurrent users.
AIX Version 1, introduced in 1986 for the IBM 6150 RT workstation, was based on UNIX System V Releases 1 and 2. In developing AIX, IBM and Interactive Systems Corporation (whom IBM contracted) also incorporated source code from 4.2 and 4.3 BSD UNIX.
Among other variants, IBM later produced AIX Version 3 (also known as AIX/6000), based on System V Release 3, for their POWER-based RS/6000 platform. Since 1990, AIX has served as the primary operating system for the RS/6000 series (later renamed IBM eServer pSeries, then IBM System p, and now IBM Power Systems). AIX Version 4, introduced in 1994, added symmetric multiprocessing with the introduction of the first RS/6000 SMP servers and continued to evolve through the 1990s, culminating with AIX 4.3.3 in 1999. Version 4.1, in a slightly modified form, was also the standard operating system for the Apple Network Server systems sold by Apple Computer to complement the Macintosh line.
In the late 1990s, under Project Monterey, IBM and the Santa Cruz Operation planned to integrate AIX and UnixWare into a single 32-bit/64-bit multiplatform UNIX with particular emphasis on running on Intel IA-64 (Itanium) architecture CPUs. A beta test version of AIX 5L for IA-64 systems was released, but according to documents released in the SCO v. IBM lawsuit, less than forty licenses for the finished Monterey Unix were ever sold before the project was terminated in 2002. In 2003, the SCO Group alleged that (among other infractions) IBM had misappropriated licensed source code from UNIX System V Release 4 for incorporation into AIX; SCO subsequently withdrew IBM's license to develop and distribute AIX. IBM maintains that their license was irrevocable, and continued to sell and support the product until the litigation was adjudicated.
AIX was a component of the 2003 SCO v. IBM lawsuit, in which the SCO Group filed a lawsuit against IBM, alleging IBM contributed SCO's intellectual property to the Linux codebase. The SCO Group, who argued they were the rightful owners of the copyrights covering the Unix operating system, attempted to revoke IBM's license to sell or distribute the AIX operating system. In March 2010, a jury returned a verdict finding that Novell, not the SCO Group, owns the rights to Unix.
AIX 6 was announced in May 2007, and it ran as an open beta from June 2007 until the general availability (GA) of AIX 6.1 on November 9, 2007. Major new features in AIX 6.1 included full role-based access control, workload partitions (which enable application mobility), enhanced security (Addition of AES encryption type for NFS v3 and v4), and Live Partition Mobility on the POWER6 hardware.
AIX 7 was announced in April 2010, and an open beta ran until general availability of AIX 7.1 in September 2010. Several new features, including better scalability, enhanced clustering and management capabilities were added. On October 5th, 2015 IBM announced AIX 7.2 release with an open beta program that is expected to run until the general availability on December 5th, 2015. Several new features to enhance reliability, security, and performance were added. One of the key new features is the Kernel Update capability which allows OS fixes to be applied to the live running kernel in a non-disruptive manner.
Supported hardware platforms
IBM 6150 RT
The original AIX (sometimes called AIX/RT) was developed for the IBM 6150 RT workstation by IBM in conjunction with Interactive Systems Corporation, who had previously ported UNIX System III to the IBM PC for IBM as PC/IX. According to its developers, the AIX source (for this initial version) consisted of one million lines of code. Installation media consisted of eight 1.2M floppy disks. The RT was based on the ROMP microprocessor, the first commercial RISC chip. This was based on a design pioneered at IBM Research (the IBM 801) .
One of the novel aspects of the RT design was the use of a microkernel, called Virtual Resource Manager (VRM). The keyboard, mouse, display, disk drives and network were all controlled by a microkernel. One could "hotkey" from one operating system to the next using the Alt-Tab key combination. Each OS in turn would get possession of the keyboard, mouse and display. Besides AIX v2, the PICK OS also utilized this microkernel.
Much of the AIX v2 kernel was written in the PL/I programming language, which proved troublesome during the migration to AIX v3. AIX v2 included full TCP/IP networking, as well as SNA and two networking file systems: NFS, licensed from Sun Microsystems, and Distributed Services (DS). DS had the distinction of being built on top of SNA, and thereby being fully compatible with DS on the IBM midrange AS/400 and mainframe systems. For the graphical user interfaces, AIX v2 came with the X10R3 and later the X10R4 and X11 versions of the X Window System from MIT, together with the Athena widget set. Compilers for Fortran and C were available. One of the more popular desktop applications was the PageMaker desktop publishing software.
IBM PS/2 series
AIX PS/2 (also known as AIX/386) was developed by Locus Computing Corporation under contract to IBM. AIX PS/2, first released in 1989, ran 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 like 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 package was priced at $195, while 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 could 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 (non-microchannel) computers as well. Support for PS/2 AIX ended in March 1995.
In 1988, IBM announced AIX/370, also developed by Locus Computing. AIX/370 was IBM's third attempt to offer Unix-like functionality for their mainframe line, specifically the System/370 (the prior versions were a TSS/370 based Unix system developed jointly with AT&T c.1980, and VM/IX, a VM/370 based system developed jointly with Interactive Systems Corporation c.1984). 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, which was based on OSF/1, and also ran on the System/390 platform. This development effort was made partly to allow IBM to compete with Amdahl UTS. Unlike AIX/370, AIX/ESA ran 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, which became MVS/ESA OpenEdition in 1999.
AIX v3 innovated in several ways on the software side. It was the first operating system to introduce the idea of a journaling file system, JFS, which allowed for fast boot times by avoiding the need to ensure the consistency of the file systems on disks (see fsck) on every reboot. Another innovation was shared libraries which avoid the need for static linking from an application to the libraries it used. The resulting smaller binaries used less of the hardware RAM to run, and used less disk space to install. Besides improving performance, it was a boon to developers: executable binaries could 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/I code and being somewhat more "pure" than v2.
Other notable subsystems included:
- IRIS GL, a 3D rendering library, the progenitor of OpenGL. IRIS GL was licensed by IBM from SGI in 1987, then still a small company which had sold only one thousand machines to date. 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-based 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 collection 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 (later acquired by HP).
- DPS on-screen display system. This was notable as a "plan B" in case the X11+Motif combination failed in the marketplace. However, it was highly proprietary, supported only by Sun, NeXT, and IBM. This cemented its failure in the marketplace in the face of the open systems challenge of X11+Motif and its lack of 3D capability.
As of 2015, AIX runs on IBM Power, System p, System i, System p5, System i5, eServer p5, eServer pSeries and eServer i5 server product lines, as well as IBM BladeCenter blades and IBM PureFlex compute nodes based on Power Architecture technology.
POWER7 AIX features
AIX 7 includes a new built-in clustering capability called Cluster Aware AIX. AIX is able to organize multiple LPARs through the multipath communications channel to neighboring CPUs, enabling very high-speed communication between processors. This enables multi-terabyte memory address range and page table access to support global petabyte shared memory space for AIX POWER7 clusters so that software developers can program a cluster as if it were a single system, without using message passing (i.e. semaphore-controlled Inter-process Communication). AIX administrators can use this new capability to cluster a pool of AIX nodes. By default, AIX V7.1 pins kernel memory and includes support to allow applications to pin their kernel stack. Pinning kernel memory and the kernel stack for applications with real-time requirements can provide performance improvements by ensuring that the kernel memory and kernel stack for an application is not paged out.
AIX POWER7 systems include the Active Memory Expansion feature, which increases system flexibility where system administrators can configure logical partitions (LPARs) to use less physical memory. For example, an LPAR running AIX appears to the OS applications to be configured with 80 GB of physical memory but the hardware actually only consumes 60 GB of physical memory. Active Memory Expansion is a virtual memory compression system which employs memory compression technology to transparently compress in-memory data, allowing more data to be placed into memory and thus expanding the memory capacity of POWER7 systems. Utilizing Active Memory Expansion can improve system utilization and increase a system’s throughput. AIX 7 automatically manages the size of memory pages used to automatically use 4 KB, 64 KB or a combination of those page sizes. This self-tuning feature results in optimized performance without administrative effort.
Apple Network Servers
The Apple Network Server systems were PowerPC-based systems designed by Apple Computer to have numerous high-end features that standard Apple hardware did not have, including swappable hard drives, redundant power supplies, and external monitoring capability. These systems were more or less based on the Power Macintosh hardware available at the time but were designed to use AIX (versions 4.1.4 or 4.1.5) as their native operating system in a specialized version specific to the ANS.
AIX V7.1, September 10, 2010
- Support for 256 cores / 1024 threads in a single LPAR
- The ability to run AIX V5.2 or V5.3 inside of a Workload Partition
- An XML profile based system configuration management utility
- Support for export of Fibre Channel adapters to WPARs
- VIOS disk support in a WPAR
- Cluster Aware AIX
- AIX Event infrastructure
- Role-based access control (RBAC) with domain support for multi-tenant environments
AIX V6.1, November 9, 2007
- Workload Partitions (WPARs) operating system-level virtualization
- Live Application Mobility
- Live Partition Mobility
- Integrated Electronic Service Agent for auto error reporting
- Concurrent Kernel Maintenance
- Kernel exploitation of POWER6 storage keys
- ProbeVue dynamic tracing
- Systems Director Console for AIX
- Integrated filesystem snapshot
- Requires POWER4 or newer CPUs
AIX 5L 5.3, August 13, 2004, end of support April 30, 2012
- NFS Version 4
- Advanced Accounting
- Virtual SCSI
- Virtual Ethernet
- Exploitation of Simultaneous multithreading (SMT)
- Micro-Partitioning enablement
- POWER5 exploitation
- JFS2 quotas
- Ability to shrink a JFS2 filesystem
- kernel scheduler has been enhanced to dynamically increase and decrease the use of virtual processors.
- AIX 5L 5.2, October 18, 2002, end of support April 30, 2009
AIX 5L 5.1, May 4, 2001 (Support discontinued April 1, 2006)
- Ability to run on an IA-64 architecture processor, although this never went beyond beta
- Minimum level required for POWER4 hardware and the last release that worked on the Micro Channel architecture
- 64-bit kernel, installed but not activated by default
- Ability to run in a Logical Partition on POWER4
- The L stands for Linux affinity
- Trusted Computing Base (TCB)
- Support for mirroring with striping
- AIX 4.3.3, September 17, 1999
- AIX 4.3.2, October 23, 1998
AIX 4.3.1, April 24, 1998
- First TCSEC security evaluation, completed December 18, 1998
- AIX 4.3, October 31, 1997
AIX 4.2.1, April 25, 1997
- NFS Version 3
- AIX 4.2, May 17, 1996
- AIX 4.1.5, November 8, 1996
- AIX 4.1.4, October 20, 1995
- AIX 4.1.3, July 7, 1995
- AIX 4.1.1, October 28, 1994
- AIX 4.1, August 12, 1994
- AIX 4.0, 1994
- AIX 3.2 1992
AIX 3.1, February 1990
- Journaled File System (JFS) filesystem type
- AIX 3.0 1989
IBM PS/2 releases
AIX PS/2 v1.1, 1989
- last version was 1.3, 1992.
IBM 6150 RT releases
- last version was 2.2.1.
- AIX v1.0, 1986
The Common Desktop Environment (CDE) is AIX's default graphical user interface. As part of Linux Affinity and the free AIX Toolboxes for Linux Applications (ATLA), open-source KDE Plasma Workspaces and GNOME desktop are also available.
System Management Interface Tool
SMIT is the System Management Interface Tool for AIX. It allows a user to navigate a menu hierarchy of commands, rather than using the command line. Invocation is typically achieved with the command
smit. Experienced system administrators make use of the
F6 function key which generates the command line that SMIT will invoke to complete it. SMIT also generates a log of commands that are performed in the
smit.script file. The
smit.script file automatically records the commands with the command flags and parameters used. The
smit.script file can be used as an executable shell script to rerun system configuration tasks. SMIT also creates the
smit.log file, which contains additional detailed information that can be used by programmers in extending the SMIT system.
smitty refer to the same program, though
smitty invokes the text-based version, while
smit will invoke an X Window System based interface if possible; however, if
smit determines that X Window System capabilities are not present, it will present the text-based version instead of failing. Determination of X Window System capabilities is typically performed by checking for the existence of the
- AOS, IBM's educational-market port of 4.3BSD
- List of Unix systems
- Operating systems timeline
- Service Update Management Assistant
- Unix Pronunciation « Around Teh Table
- Improving Database Performance With AIX Concurrent I/O - White Paper
- IBM Software Support Lifecycle (XML)
- Unigroup Next Meeting Announcement
- IBM Press Release
- AIX & UNIX dW Zone
- AIX Fix Central
- AIX Forum
- AIX User Groups
- Submit AIX Requirements
- AIX Toolbox for Linux Applications
- AIX version 5.3 Documentation
- AIX version 6.1 information center
- AIX version 6.1 overview
- AIX Wiki
- AIX/ESA V2R2 General Information
- IBM AIX page
- IBM Systems AIX Magazine
- IBM Electronic Service Agent
- AIX Health Check
- Rootvg.net - Independent Portal for AIX & POWER
- AIX shell accounts
- AIX Commands, Tools, Scripts and Explanations
- 80-page marketing booklet from 1989 explaining IBM's AIX vision at the time