Red Hat Linux 9.0.93 Release Notes

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The Red Hat Linux installation program has the ability to test the integrity of the installation media. It works with the CD, DVD, hard drive ISO, and NFS ISO installation methods. Red Hat recommends that you test all installation media before starting the installation process, and before reporting any installation-related bugs (many of the bugs reported are actually due to improperly-burned CDs). To use this test, type linux mediacheck at the boot: prompt.

During a graphical installation, you can press SHIFT-Print Screen and a screenshot of the current installation screen will be taken. These are stored in the following directory:

/root/anaconda-screenshots/

The screenshots can be accessed once the newly-installed system is rebooted.

Certain hardware configurations (particularly those with LCD displays) may experience problems while starting the Red Hat Linux installation program. In these instances, restart the installation, and add the "nofb" option to the boot command line.

NOTE: Chinese, Japanese, and Korean graphical installations started using the "nofb" option will start in English, and then switch to the appropriate language once the graphical phase of the installation process begins.

Some Sony VAIO® notebook systems may experience problems installing Red Hat Linux from CD-ROM. If this happens, restart the installation process and add the following option to the boot command line:

pci=off ide1=0x180,0x386

This option allows the installation to proceed normally; any devices not detected due to the use of this option will be configured the first time Red Hat Linux is booted.

Red Hat Linux 9.0.93 now supports graphical FTP and HTTP installations. The default for these installation modes remains text-based; however, graphical installations can be enabled by passing "graphical" as a boot-time option.

Note that graphical FTP and HTTP installations increase memory requirements by approximately 64MB, due to the necessity of containing the installer image. However, if you boot the installation program from CD-ROM 1, no additional RAM will be required; instead the installer image will be mounted from the CD-ROM.

Hard drive installations are now graphical by default. There is no memory penalty, as parted now uses a kernel interface that makes it possible to keep partitions mounted on a device while other partitions are being modified.

Installation via VNC is now supported. To initiate a VNC-based installation, pass "vnc" as a boot-time option. If necessary, a password can be set by adding "vncpassword=<password>" to the boot-time options. The VNC display will be "<host>:1", where <host> is the IP address or hostname of the system installing Red Hat Linux.

There have been issues observed when upgrading Red Hat Linux 7.<x>, 8.0, 9 and 9.0.93 systems running Ximian GNOME. The issue is caused by version overlap between the official Red Hat Linux RPMs and the Ximian RPMs. This configuration is not supported. You have several choices in resolving this issue:

1) You may remove Ximian GNOME from your Red Hat Linux system prior to upgrading Red Hat Linux.

2) You may upgrade Red Hat Linux, and then immediately reinstall Ximian GNOME.

3) You may upgrade Red Hat Linux, and then immediately remove all remaining Ximian RPMs, and replace them with the corresponding Red Hat Linux RPMs.

You must resolve the version overlap using one of the above choices. Failure to do so will result in an unstable GNOME configuration.

There has been some confusion regarding font-related issues under the X Window System in recent versions of Red Hat Linux. At the present time, there are two font subsystems, each with different characteristics:

- The original (15+ year old) subsystem is referred to as the "core X font subsystem". Fonts rendered by this subsystem are not anti-aliased, are handled by the X server, and have names like:

-misc-fixed-medium-r-normal--10-100-75-75-c-60-iso8859-1

The newer font subsystem is known as "fontconfig", and allows applications direct access to the font files. Fontconfig is often used along with the "Xft" library, which allows applications to render fontconfig fonts to the screen with antialiasing. Fontconfig uses more human-friendly names like:

Luxi Sans-10

Over time, fontconfig/Xft will replace the core X font subsystem. At the present time, applications using the Qt 3 or GTK 2 toolkits (which would include KDE and GNOME applications) use the fontconfig and Xft font subsystem; most everything else uses the core X fonts.

In the future, Red Hat Linux may support only fontconfig/Xft in place of the XFS font server as the default local font access method.

NOTE: An exception to the font subsystem usage outlined above is OpenOffice.org (which uses its own font rendering technology).

If you wish to add new fonts to your Red Hat Linux 9.0.93 system, you must be aware that the steps necessary depend on which font subsystem is to use the new fonts. For the core X font subsystem, you must:

1. Create the /usr/share/fonts/local/ directory (if it doesn't already exist):

mkdir /usr/share/fonts/local/

2. Copy the new font file into /usr/share/fonts/local/

3. Update the font information by issuing the following commands (note that, due to formatting restrictions, the following commands may appear on more than one line; in use, each command should be entered on a single line):

ttmkfdir -d /usr/share/fonts/local/ -o /usr/share/fonts/local/fonts.scale

mkfontdir /usr/share/local/

4. If you had to create /usr/share/fonts/local/, you must then add it to the X font server (xfs) path:

chkfontpath --add /usr/share/fonts/local/

Adding new fonts to the fontconfig font subsystem is more straightforward; the new font file only needs to be copied into the /usr/share/fonts/ directory (individual users can modify their personal font configuration by copying the font file into the ~/.fonts/ directory).

After the new font has been copied, use fc-cache to update the font information cache:

fc-cache <directory>

(Where <directory> would be either the /usr/share/fonts/ or ~/.fonts/ directories.)

Individual users may also install fonts graphically, by browsing fonts:/// in Nautilus, and dragging the new font files there.

NOTE: If the font filename ends with ".gz", it has been compressed with gzip, and must be decompressed (with the gunzip command) before the fontconfig font subsystem can use the font.

Due to the transition to the new font system based on fontconfig/Xft, GTK+ 1.2 applications are not affected by any changes made via the Font Preferences dialog. For these applications, a font can be configured by adding the following lines to the file ~/.gtkrc.mine:

style "user-font" {

fontset = "<font-specification>"

}

widget_class "*" style "user-font"

(Where <font-specification> represents a font specification in the style used by traditional X applications, such as "-adobe-helvetica-medium-r-normal--*-120-*-*-*-*-*-*".)

Red Hat Linux 9.0.93 now uses a graphical interface while booting. The graphical boot screen will appear once the kernel has loaded. Presently the graphical boot interface has known issues with respect to interactions with the Kudzu hardware probing tool; work on resolving these issues is proceeding. Graphical booting is controlled by the GRAPHICAL line in the /etc/sysconfig/init file; set it to "no" to permanently disable graphical booting.

To disable graphical booting at boot-time, append "nogui" to your bootloader command line.

For proper Java operation, the Mozilla Web browser requires a Java plugin compatible with gcc32 (such as Sun j2re 1.4.2).

Historically, the SSH and Telnet protocols have not included negotiation of the character encoding to be used for text sent over the connection. Instead, it has been assumed that both ends will use Latin-1, Latin-2, UTF-8, EUC-JP, or whatever the most appropriate character encoding for the user's language might be.

Red Hat Linux has made a transition from single-locale encodings such as Latin-1 to UTF-8. As a result, you may have problems when making a Telnet or SSH connection between newer versions of Red Hat Linux and older versions, or between newer versions of Red Hat Linux and other operating systems. Symptoms of possible problems include (for example) a mangled display in "mc", or the inability to read non-ASCII files.

In the long term, all systems are expected to migrate to UTF-8, eliminating this issue. In the short term, there are some workarounds to be aware of:

- In gnome-terminal, the "Terminal->Character Coding" menu allows you to force a specific encoding.

- The xterm(1) and luit(1) man pages describe the -en and -lc options, which can be useful.

- The iconv command line utility, especially with the -c option to handle invalid characters, can be useful for converting files to other encodings.

As part of the migration to UTF-8, some issues should be kept in mind:

- Filenames located on ext3 file systems should be in UTF-8.

- The input of non-ASCII characters from the system console is not possible; only graphical applications support the input of these characters.

- Some languages currently do not display correctly in Red Hat Linux 9.0.93. These languages include Greek, and Gaelic (both types).

The default system and user encoding for Japanese, Korean, Simplified Chinese and Traditional Chinese locale has changed to UTF-8.

For backward compatibility support in the legacy character set, you can override your existing locale by editing /etc/sysconfig/i18n or ~/.i18n. Changes made to the /etc/sysconfig/i18n file effect the entire system, while changes made to the ~/.i18n file only effect that user's login session.

You can also pass a LANG environment variable when you run a application to change the character set:

LANG=ja_JP.eucJP gedit

You can also view files using different encodings in a virtual terminal by using the following command:

lv <filename>

Current known issues to new locales — Korean man pages are still in the legacy character set.

OpenLDAP Upgrade-Related Notes — The on-disk storage format used by slapd, the standalone OpenLDAP server binary, has changed. Users upgrading LDAP servers from previous releases of Red Hat Linux must dump their directories to LDIF files using slapcat and re-import them into the new format using slapadd.

Because OpenLDAP now uses version 2 of the Cyrus SASL library, secrets stored in databases used by version 1 of the SASL library will not be usable for authenticating clients to an LDAP directory server. Administrators can generate an initial database for use with version 2 of the library by running the following command:

dbconverter-2 /etc/sasldb

By default, the Sendmail mail transport agent (MTA) does not accept network connections from any host other than the local computer. If you want to configure Sendmail as a server for other clients, you must edit /etc/mail/sendmail.mc and change the DAEMON_OPTIONS line to also listen on network devices (or comment out this option entirely using the dnl comment delimiter). You must then regenerate /etc/mail/sendmail.cf by running the following command (as root):

make -C /etc/mail

Note that you must have the sendmail-cf package installed for this to work.

The Red Hat Linux 9.0.93 kernel includes support for ACPI (Advanced Configuration and Power Interface). When booting the Red Hat Linux installation program from CD (and booting the installed system) this kernel uses ACPI on some systems (depending on certain factors such as whether the hardware supports ACPI and the date of its BIOS ACPI implementation). ACPI is used for device enumeration (but not for sleeping). You can disable ACPI by using the following boot option:

acpi=off

NOTE: The ACPI subsystem results in a kernel too big to fit on a diskette; therefore, the kernel placed on boot diskettes does not include ACPI support. In addition, because of these size issues, emergency boot diskettes will not work. You must use rescue mode from the installer instead of an emergency boot diskette.

The Red Hat Linux 9.0.93 kernel includes new Exec-shield functionality Exec-shield is a security-enhancing modification to the Linux kernel that makes large parts of programs — including their stack — not executable. This can reduce the potential damage of some security holes. Exec-shield is related to the older "non-exec stack patch" but has the potential to provide much greater protection.

Exec-shield's behavior can be controlled via the proc file system. The command used is:

echo <value> > /proc/sys/kernel/exec-shield

Where <value> is one of the following:

- 0 — Exec-shield is always disabled

- 1 — Exec-shield is disabled, except for binaries that enable it

- 2 — Exec-shield is enabled, except for binaries that disable it

- 3 — Exec-shield is disabled

NOTE: Binary marking (the ability to identify those binaries that should run with Exec-shield enabled/disabled) is not yet implemented.

The Red Hat Linux 9.0.93 kernel now makes it possible to prevent the loading of kernel modules. This can be useful for system administrators wanting to ensure that only a strictly-controlled set of modules are loaded. To disable kernel module loading, issue the following command:

echo off > /proc/modules

Once this command has been issued, all further attempts to load kernel modules will fail.

NOTE: Once kernel module loading has been disabled, a reboot is required to re-enable it.

The Red Hat Linux 9.0.93 kernel now includes support for laptop mode. When placed in laptop mode, the kernel batches disk I/O, allowing the disk drive to become idle long enough for the drive's power-saving features to take affect. This can result in significant increases in battery runtime.

To enable laptop mode, issue the following command:

echo 1 > /proc/sys/vm/laptop_mode

To disable laptop mode, issue the following command:

echo 0 > /proc/sys/vm/laptop_mode

NOTE: The APM scripts included with Red Hat Linux 9.0.93 automatically enable laptop mode when switching to battery power.