Patches are fixes that a computer company makes for its software to fix a problem and sometimes to enhance it or add a new feature.  Sometimes, patches completely fix a problem and the word patch is a misnomer.  SGI's have their share of patches, as do all systems.  Patches can be needed for all parts of the system's software, from low-level I/O code that's being constantly used to the most specific part of a high-level user application.  This page is for instructing you on how to install SGI IRIX patches(which includes Y2K patches) and SGI compiler patches, as these are the most frequent cases of patching needed.  Luckily, the days of patching OS's is almost over.  IRIX 6.5 has eliminated almost all of this with the new IRIX 6.5 release system, but there are still cases where patches could be needed with 6.5.   Many systems still run versions of IRIX < 6.5 which require recommended patch sets and security patches.  This page will describe the structure of IRIX patches and explain how to install patches.
 

    Patches come from SGI in inst-format. They have a special designation in inst-format as being a patch, though, called "P".   Installable patches have an "A" next to them.  Individual patches can be installed like any software product.  See the page on using inst to see how to do this.

Recommended patches:
    Recommended patches are patches that are required for stable system operation.  Each version of IRIX < 6.5 used to come out with a recommended patch set each month.  That was shortenened to once every 3 months.  When IRIX 5.3, 6.3 and 6.4 became no longer supported, the latest patch set was frozen with a few exceptions.  One, some of the Y2K patches for these versions of IRIX were added later on, and there may be some later security patches added also.

Installing recommended patches for IRIX 5.3, 6.2, 6.3, 6.4:

1. Make a full backup of your system.
2. Obtain and de-tar the patch tar file for your version of the OS.  I suggest creating a directory, /usr/tmp/patches and de-tarring there.  Don't use /tmp since it is erased on system startup.
3. Make sure you know the system's hostname and IP address.
4. Put the OS CD for your system in the CD-ROM drive.
5. Shut the system down to PROM.  "/etc/shutdown -y -g0 -i0"
6. When it reaches the PROM menu, select option 2, "Install System Software"  This will cause the system to install and boot to miniroot, a minimal stripped-down version of the OS for major tasks that affect the OS.  Don't worry, the miniroot will be installed on the swap partition and won't damage your usual system partition.  The usual system partition is mounted at /root in miniroot.  This could take up to 10 minutes.
7. When it's finished, an inst prompt will appear.
8. Select item one, and for the locatio of the software distribution enter "/root/usr/tmp/patches".
9. A startup script should launch.  This will automatically select which patches need to be installed.  If it doesn't, enter "i P",  "keep S" then "keep D"
10. Enter "conflicts" to resolve any conflicts.
11. Enter "go" to start the installation.

Security patches:
    See section on security patches under Security Improvement.

Compiler patches:
    Same as for Recommended patches, although you rarely need to shut down to miniroot.  Check the README file with the patches to be sure.
 

last updated 2/28/00 by Martin McCormick, martinm@sas.upenn.edu