Key New Features and Changes

The goal of the IRIX 6.5 release family is to provide a high quality and stable operating system for all SGI systems. Significant additional software has been packaged with IRIX 6.5, including some important system and network management and interoperability tools.

This page contains a partial list of the key new features and changes for IRIX 6.5.27. To see the list of key features and changes for the IRIX 6.5 and IRIX 6.5.1 through 6.5.26 releases, see the previous IRIX features page.

For information about supported hardware and peripherals in IRIX 6.5.27, see the Minimum Requirements page.

Look for information about the IRIX 6.5 release family on Supportfolio Online ( and

For details on any of these new features and changes, refer to the release notes.

Note: Some features listed here apply only for certain software bundles or hardware configurations.

Packaging and Support Changes for IRIX 6.5.27

  • CXFS Support

    CXFS will be supported with IRIX 6.5.27 as an asynchronous product. The CXFS release for IRIX 6.5.27 must be ordered separately. For more information, consult your SGI service representative.

  • Changes to Fonts, PostScript(TM) Viewing, and PDF Viewing Tools

    Several of the fonts were updated for the IRIX 6.5.23 release, and as a result, customers may notice a change in some of the filenames used in the font directories. You may also see some minor changes to the fonts' appearance on the display. Applications that use fonts through the standard mechanisms in X11 should continue to operate correctly. Applications that directly access those font files in the DPS directory, however, may find that the file has been superseded and no longer exists in that location. Developers are encouraged to use the standard X11 mechanisms for accessing fonts to avoid this problem.

    The tools acroread (Adobe Acrobat® Reader), xpsview, and showps have been replaced with the more recent open source tools gsview and xpdf, which are built on top of the Ghostscript® package. These tools can be found on the Applications CD in this release. Customers who made use of the old tools should ensure that they install the new ones by selecting the images for gsview, xpdf, and ghostscript from the Applications CD. The old tools will no longer be available, and will be replaced with wrapper scripts.

    The wrappers for acroread and xpsview/showps will invoke the new xpdf or gsview commands respectively, but the wrapper scripts will pass all parameters verbatim, and will not attempt any translation. Thus, if an option changes or is not available for the new tool, customers may encounter an error if they use that option with the old command name from inside a script, for instance.

    Ghostscript is a registered trademark of Artifex Software, Inc. PostScript is a trademark and Acrobat is a registered trademark of Adobe Systems Incorporated.

IRIX 6.5.27 Key New Features

The following changes have been incorporated into the core IRIX 6.5.27 overlay CDs and the Applications CD.

New Software Enhancements

  • Volatile cpusets
    The IRIX 6.5.27 release supports volatile cpusets, which are cpusets that can be configured, created, and destroyed by regular users. Users that need to isolate work in non-batch environments can use this feature to achieve their needs without root access or the Scheduling. For information, see the cpuset(1) and cpuset(5) man pages.

  • Tracking priority inheritance
    In the IRIX 6.57 release, enabling the "scheduler" event-mask logs priority inheritance actions to rtmon logs. Developers can use these new trace records to analyze the real-time behavior of their applications. For information, see the rtmon-client(1) man page.

  • NFS over IPv6
    In the IRIX 6.5.27 release, NFS over IPv6 is supported for both client and server.

  • OpenSSH version 3.9p1
    The included OpenSSH protocol suite in the IRIX 6.5.27 release has been upgraded to version 3.9p1.

  • Motif version 2.1.32
    In IRIX 6.5.27, Motif 2.1.20 has been upgraded to Motif 2.1.32. This version is a bug fix and compatibility update.

  • New cpuset_tobind systune parameter
    The IRIX 6.5.27 release provides the new system tuneable variable, cpuset_tobind. This variable limits how the runon command and the sysmp system call with MP_MUSTRUN command can be used. The cpuset_tobind variable is a boolean variable with the default setting of 0. Setting this variable to 1 indicates that for a thread to bind to a CPU using runon, sysmp MP_MUSTRUN, or a related operation, the CPU must be restricted, isolated, or part of a cpuset. For information, see the dplace(1), runon(1), sysmp(2), pthread_setrunon_np(3P), and cpuset(1) man pages.

  • New parameters to manage highest available file descriptor
    The IRIX 6.5.27 release provides the new system tuneable parameters rlimit_nofile_cur_clamps_setrlimit and rlimit_nofile_cur_clamps_fdhi. These system variables are boolean, with a default setting of 0 indicating that they are inactive.

    The rlimit_nofile_cur_clamps_setrlimit variable, if set to 1, controls the behavior of the setrlimit and setrlimit64 system calls. In this case a call to setrlimit(RLIMIT_NOFILE, &rlimit) where rlimit.rlim_cur will result in leaving open file descriptors with values above the new limit will result in a return of EINVAL. For information see the getrlmit(2) man page.

    The rlimit_nofile_cur_clamps_fdhi variable, if set to 1, affects the behavior of the getdtablehi system call. In this case if there are open file descriptors with values above the current process limit, then the current process limit is returned. For information, see the getdtablehi(3C) man page.

    In addition to the new system tuning variables, the F_CLOSEM command has been added to the fcntl system call. The F_CLOSEM command will close all file descriptors greater than or equal to the file descriptor number supplied by the caller. For information, see the fcntl(2) getdtablehi(3C) man page.

  • PAM authentication support for SUNOS C2 security NIS master server
    In IRIX 6.5.27, user authentication using PAM now supports IRIX as a client of Sun NIS master servers with C2 security using passwd.adjunct NIS maps.

  • pam_tally module added for login tallying
    In IRIX 6.5.27, login/rsh/rlogin/telnet can make use of the pam_tally module to maintain a count of unsuccessful login and deny access if too many attempts fail.

SGI Software Product Life Cycle Management

In accordance with the SGI software product life cycle management strategy announced in December 2002, SGI will announce support mode changes for various software products on a semiannual basis. To view customer letters containing support mode changes announced since December 2002, as well as the latest IRIX Support Policy documents, visit the IRIX Support Policy Web page on Supportfolio Online.

IRIX OS Bundled Software

For information about the bundled software that is included on the Applications CD with this release, see CD Contents and the Bundled software and licenses web page.

System Platform Bundles

No changes have been made to the demonstration software CDs developed for the specific system platforms.


Freeware products and revisions supported for this release can be downloaded from As of the IRIX 6.5.22 release, IRIX Freeware CDs are no longer included with the IRIX Update kit.


The following manuals have been revised for this release:

  • ONC3/NFS Administrator's Guide (007-0850-170) includes information about the nfsstat(1M) command.

  • XVM Volume Manager Administrator's Guide (007-4003-018) includes new information about the XVM snapshot feature.