IBM AIX (operating system)

From Wikipedia, the free encyclopedia

(Redirected from AIX (operating system))
Jump to: navigation, search
AIX
Image:Aix logo.gif
Website IBM AIX 5L
Company/
developer
IBM
OS family UNIX System V
Source model Closed source
Latest stable release 6.1 / November, 2007
Kernel type Dynamic Extendable
Default user interface Common Desktop Environment
License Proprietary
Working state Current

AIX (Advanced Interactive eXecutive) is the name given to a series of proprietary operating systems sold by IBM for several of its computer system platforms, based on UNIX System V with 4.3BSD-compatible command and programming interface extensions.

The AIX 5L 5.3 release supports up to 64 IBM POWER or PowerPC architecture central processing units and two terabytes (TB) of random access memory. The JFS2 file system - first introduced by IBM as part of AIX - supports computer files and partitions over 16 TB in size (though that's the tested limit and recommended maximum).

Contents

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 4.3BSD UNIX.

Among other variants, IBM later produced AIX Version 3 (also known as AIX/6000), based on System V Release 3, for their IBM POWER-based RS/6000 platform. Since 1990, AIX has served as the primary operating system for the RS/6000 series (now called System p by IBM).

AIX Version 4, introduced in 1994, introduced support for symmetric multiprocessing with the introduction of the first RS/6000 SMP servers. AIX Version 4 continued to evolve though the 1990s culminating with the introduction of AIX 4.3.3 in 1999.

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 supporting the Intel IA-64 architecture. This never came to fruition, though a beta test version of AIX 5L for IA-64 systems was released.

AIX 6 was announced in May 2007 and ran an open beta from June 2007 until the general availability (GA) of AIX 6.1 on November 9th, 2007. Major new features in AIX 6.1 are full RBAC, Workload Partitions (WPAR) enabling application mobility, and Live Partition Mobility on the new POWER6 hardware.

See also: SCO v. IBM and SCO v. Novell

In the SCO v. IBM lawsuit filed in 2003, the SCO Group alleged that (among other infractions) IBM 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 continues to sell and support the product pending the outcome of litigation.

On the 10th August, 2007 a U.S. district court judge ruled that SCO does not own the copyrights to the Unix operating system. The court informed Novell that it could now force SCO to waive its lawsuit against IBM. Further, the court ruled that SCO must pay Novell most of the license revenue that SCO secured from Sun Microsystems Inc. and Microsoft Corp. for their use of Unix technologies.

Many people feel that this ruling is the death-knell in SCO's legal fight.[citation needed]

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. Installation media consisted of eight 1.2M floppy disks. The RT was based on the ROMP chip, the first commercial RISC chip, based on a design, the IBM 801, pioneered at IBM Research.

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, which allowed multiple operating systems to be booted and run at the same time. 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 support, as well as SNA, and two networking file systems: NFS, licensed from Sun Microsystems, and Distributed Services or 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.

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, supported IBM PS/2 personal computers with Intel 386 or later processors.

In 1988, IBM announced AIX/370, also developed by Locus Computing. AIX/370 was IBM's first 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, 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.

The release of AIX version 3 (sometimes called AIX/6000) coincided with the announcement of the first IBM RS/6000 models. The RS/6000 was unique in that it not only outperformed all other machines in integer compute performance, but also beat the competition by a factor of 10 in floating-point performance.[citation needed]

Releases of AIX version 3 also took advantage of the developments in the POWER architecture.

AIX v3 innovated in several ways on the software side. It was the first operating system to introduce the idea of a journalling file system, JFS, which allowed for fast boot times by avoiding the need to fsck the disks on every reboot. Another innovation was the introduction of shared libraries, which avoided the need for an application to statically link to the libraries it used. The resulting smaller binaries used less of the hardware RAM, to run, and used less of the disk space to install. Besides improving performance, it was a boon to developers: executable binaries could be in the 10s of kilobytes instead of a megabyte for an executable statically linked to the C library. AIX v3 also ditched the microkernel of AIX v2, a contentious move that resulted in v3 being somewhat more "pure" (and containing no PL/1 code) than v2.

Other notable subsytems included:

  • IRIS GL, a 3D rendering library, the progenitor of OpenGL. IrisGL was licensed by IBM from SGI, then 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 990K vectors per second.
  • PHIGS, another 3D rendering API, popular in automotive CAD/CAM circles, and at the core of CATIA.
  • Full support for 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 purchased by HP)
  • The NeXT windowing system (NeXT DPS). This was notable as a "plan B", in case the X11/Motif/IrisGL combination failed in the marketplace. In almost every way, NeXT was a better technology, and had better and more interesting features than X11/Motif. However, it was highly proprietary: it hadn't been licensed to any other Unix vendor. This, in the face of the open systems challenge of X11/Motif and its lack of 3D support, cemented its failure in the marketplace.

As of 2007, the current release of AIX supports the RS/6000 and System p, BladeCenter JS-series, IntelliStation POWER, and System i5 platforms.

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.

AIX was only compatible with the Network Servers and was not ported to standard Power Macintosh hardware. Not to be confused is A/UX, Apple's earlier version of Unix for 68k-based Macintoshes.

As part of Project Monterey, a beta test version of AIX 5L was released for the IA-64 (Itanium) architecture in 2001, but this was abandoned before it became an official product.

  • AIX 4.3.3, September 17,1999
    • Added online backup function
    • Workload Management (WLM)
  • AIX 4.3.2, October 23,1998
  • AIX 4.3.1, April 24,1998
  • AIX 4.3, October 31,1997
  • AIX 4.2.1, April 25,1997
    • NFS Version 3 support
  • 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
    • Introduced support for RS/6000 systems with PowerPC processors and PCI busses.
  • AIX 3.2 1992
  • AIX 3.1
    • Introduction of Journaled File System (JFS)
  • AIX 3.0, February 1990
    • LVM (Logical Volume Manager) was incorporated into OSF/1.
    • SMIT was introduced.

  • AIX PS/2 v1.1, 1989
    • last version was 1.3, 1992.

  • AIX v1.0, 1986
  • AIX v2.0
    • last version was 2.2.1.

The Common Desktop Environment (CDE) is AIX's default graphical user interface. As part of Linux Affinity and the free AIX Toolbox for Linux Applications (ATLA), open-source KDE and GNOME desktop are also available.

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 the proposed task.

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.

smit and smitty refer to the same program, though smitty invokes the text-based version, while smit will invoke an X Window based interface if possible; however, if smit determines that X Window capabilities are not present, it will present the text-based version instead of failing. Determination of X Window capabilities is typically performed by checking for the existence of the DISPLAY variable.

  • AOS, IBM's educational-market port of 4.3BSD

Advanced Search
Included Web Search Engines


Safe Search

close

Top Matching Results

Occasionally Search.com will highlight specialized results that are based on the context of your query. Examples of specialized results include specific links to news, images, or video.

Top Matching Results may highlight information from other Search.com pages, content from the CNET Network of sites, or third party content. The listings are based purely on relevance. Search.com does not receive payment for listings in this section but our partners that provide this data may get paid for listing these products.

Sponsored Links

This section contains paid listings which have been purchased by companies that want to have their sites appear for specific search terms and related content. These listings are administered, sorted and maintained by a third party and are not endorsed by Search.com.

Search Results

Search.com sends your search query to several search engines at one time and integrates the results into one list which has been sorted by relevance using Search.com's proprietary algorithm. You can customize the list of search engines included in your metasearch from the preferences.

The search engines that are used in your metasearch may allow companies to pay to have their Web sites included within the results. To view the Paid Inclusion policy for a specific search engine, please visit their Web site. Search.com does not accept payment or share revenue with any search engine partner for listings in this section.