The following topics are covered in this document:

  • Release Notes Updates

  • Installation-Related Notes

  • General Information

  • Technology Previews

  • Kernel Notes

  • Changes to Drivers and Hardware Support

Some updates on Red Hat Enterprise Linux 4 Update 5 may not appear in this version of the Release Notes. An updated version of the Red Hat Enterprise Linux 4 Update 5 Release Notes may also be available at the following URL:

Release Notes Updates

This section contains information that was not included in the distribution version of the Red Hat Enterprise Linux 5 Release Notes.

  • The OpenIB Infiniband network and clustering stack is now fully supported. InfiniBand is a high-speed switched fabric communications link primarily used in high-performance computing. This feature was originally introduced as a Technology Preview in Red Hat Enterprise Linux 4 Update 3.

    At present, only mthca-based InfiniBand HCA (Host Channel Adapter) cards are supported.

  • In-kernel key management is now fully supported. This facility permits the association of key sets (or keyrings) with file system processes (such as OpenAFS) and other applicable subsystems. To enable in-kernel key management, use the CONFIG_KEYS option in the kernel configuration. Keys can then be manipulated through the keyctl utility in the keyutils package.

    This feature was originally introduced as a Technology Preview in Red Hat Enterprise Linux 4 Update 2.

  • The GNU Compiler Collection (gcc-4.1) is still included in this release as a Technology Preview. This compiler was originally introduced as a Technology preview in Red Hat Enterprise Linux 4 Update 4.

    For more information about gcc-4.1, refer to the project website at An in-depth manual for gcc-4.1.2 can also be read at

  • OpenOffice 2.0 is now included in this release as a Technology Preview. This suite features several improvements, including ODF and PDF functionalities, support for digital signatures and greater compatibility with open suites in terms of format and interface. In addition to this, the OpenOffice 2.0 spreadsheet has enhanced pivot table support, and can now handle up to 65,000 rows.

    For more information about OpenOffice 2.0, please refer to

  • The QLogic driver in Red Hat Enterprise Linux 4 has two components: the main driver and a hardware-specific firmware loader. Both components must be loaded for the driver to work. Currently, the module use count for the main driver is incremented when the attached storage device is in use. The use count for firmware loader modules is not incremented.

    As a result, the system does not automatically prevent you from performing an rmmod on the firmware module even when it is in use. Doing so will result in I/O errors.

    As such, you should never remove the firmware module while the main driver module is still in use.

  • The lvm-2.02.01-1.3 package is dependent on kernel version 2.6.9-24.EL or higher. However, the installation of this lvm package will not fail if you do not have the correct kernel version installed.

    As such, to install lvm, you should verify first if you have the correct kernel version and manually upgrade if necessary.

  • Removing mpt modules may cause a panic in scsi_mod. As such, you should not rmmod any mpt modules

  • The QLogic iSCSI Expansion Card for IBM BladeCenter provides both Ethernet and iSCSI functions. Some parts on the card are shared by both functions. The current qla3xxx and qla4xxx drivers support Ethernet and iSCSI function individually. They do not support the use of both functions simultaneously.

    Using both Ethernet and iSCSI functions simultaneously may hang the device, causing data loss and file system corruption on iSCSI devices or network disruptions on Ethernet.

  • When Red Hat Enterprise Linux runs in in LPAR, it attempts to acquire information about all devices granted to the LPAR. This could result in an out-of-memory condition. As such, when installing Linux on an LPAR (Logical Partition), ensure that the kernel can only detect devices that are used by the Red Hat Enterprise Linux system.

    To do this, use the cio_ignore parameter of zipl at boot time. Setting the cio_ignore parameter creates a blacklist of devices that the kernel should not detect.

    To set the cio_ignore parameter interactively, run zipl and enter the following command:

    cio_ignore=all,]device 1,]device 2,]device 3

    where device 1, device 2, and device 3 are valid LPAR device numbers of devices you want to include in the blacklist. The right square bracket (]) is interpreted as a logical NOT in the interactive command line.

    After booting, you can set these parameters permanently, by editing the /etc/zipl.conf file to include the cio_ignore option in the [ipl] section. Simply replace the right square bracket (]) with an exclamation point (!).

Installation-Related Notes

The following section includes information specific to installation of Red Hat Enterprise Linux and the Anaconda installation program.


In order to upgrade an existing Red Hat Enterprise Linux 4 installation to Update 5, you must use Red Hat Network to update those packages that have changed.

You may use Anaconda to perform a fresh installation of Red Hat Enterprise Linux 4 Update 5 or to perform an upgrade from the latest updated version of Red Hat Enterprise Linux 4.

  • If you are copying the contents of the Red Hat Enterprise Linux 4 Update 5 CD-ROMs (in preparation for a network-based installation, for example) be sure you copy the CD-ROMs for the operating system only. Do not copy the Supplementary CD-ROM, or any of the layered product CD-ROMs, as this will overwrite files necessary for Anaconda's proper operation.

    These CD-ROMs must be installed after Red Hat Enterprise Linux has been installed.

  • If you installed Red Hat Enterprise Linux 4 Update 5 through a serial console, the login prompt may not appear. To work around this, open /etc/yaboot.conf and locate the following line:

            append="console=tty0 console=ttyS4 rhgb quiet"

    Edit this line by switching the order of console=tty0 and console=ttyS4 such that the line now reads as follows:

    	append="console=ttyS4 console=tty0 rhgb quiet"

General Information

ql2xfailover Support and Multipath

Red Hat Enterprise Linux 4 does not include support for ql2xfailover, as it has not been accepted upstream.

To implement multipathing, use mdadm instead. For more information about dm-multipath, consult its man page using the command man multipath.

MCFG on AMD-based Systems

During PCI probing, Red Hat Enterprise Linux 4 Update 5 attempts to use information obtained from MCFG (memory-mapped PCI configuration space). On AMD-systems, this type of access does not work on some buses, as the kernel cannot parse the MCFG table.

To work around this, add the parameter pci=conf1 or pci=nommconf on the kernel boot line in /etc/grub.conf. For example:

title Red Hat Enterprise Linux AS (2.6.9-42.0.2.EL)
        root (hd0,0)
        kernel /vmlinuz-2.6.9-42.0.2.EL ro root=/dev/VolGroup00/LogVol00 rhgb quiet pci=conf1
        initrd /initrd-2.6.9-42.0.2.EL.img

Doing this instructs the kernel to use PCI Conf1 access instead of MCFG-based access.

Rollbacks Using up2date

The up2date options --undo and list-rollbacks are now deprecated. Currently, the recommended method for performing a rollback is to use the Multi-state Rollback feature provided by the Provisioning entitlement on Red Hat Network. For more information about this, refer to

Alternatively, you can also downgrade an RPM manually. To do this, obtain the old RPM and run the following command:

rpm -Uvh --oldpackage --nosignature --nodigest <filename of old RPM>


Red Hat Enterprise Linux 4 Update 5 is now supported as a paravirtualized guest, but cannot be used as dom0.

At present, paravirtualization for Red Hat Enterprise Linux 4 Update 5 has the following issues:

  • The PV-FB (ParaVirtualized FrameBuffer) currently does not support keymaps other than en-US. As such, other keyboards may not be able to type certain keystrokes. This issue will be addressed in a future update of Red Hat Enterprise Linux 4.

  • Paravirtualized domains can only auto-detect relative mouse movement, and pointer movement is rather erratic. This will be addressed in a future update of Red Hat Enterprise Linux 4.

  • Only virtualized network and disk devices are supported on paravirtualized guests. Direct control by guests of PCI, USB, printer or serial devices is not supported.

Slow Disk Dump

Slow disk dump may be improved using the block_order parameter. This parameter specifies the I/O block size to be used when writing the dump. Testing has shown that the default value 2 works well for most adapters and system configurations.

Note that disk dumps on Megaraid hardware (in certain system platforms and under certain configurations) may be prohibitively slow. To address this, increase the value of the block_order parameter.

Larger block_order values consume more module memory. For more information about the block_order parameter, refer to /usr/share/doc/diskdumputils-<version>/README (replace <version> with the corresponding version of the diskdumputils package installed).

iSeries Access for Linux

The iSeries ODBC Driver for Linux has been replaced by a new product -- the iSeries Access for Linux. This new product can be downloaded at the following link:

iSeries Access for Linux is the latest offering in the iSeries Access product line. It offers Linux-based access to iSeries servers. iSeries Access for Linux allows you to :

  • Access the DB2 UDB (Universal Database) for iSeries using its ODBC Driver

  • Establish a 5250 session to an iSeries server from a Linux client

  • Access the DB2 UDB via the EDRS (Extended Dynamic Remote SQL) driver

  • Support 32-bit (i386 and PowerPC) and 64-bit (x86-64 and PowerPC) platforms


The ibmasm package is used to facilitate communication with the IBM Advance System Management PCI Adapter, also known as RSA I. If you are using the RSA II, you need to manually uninstall the ibmasm package after downloading the corresponding package for RSA II.

Technology Previews

Technology Preview features are currently not supported under Red Hat Enterprise Linux 4 Update 5 subscription services, may not be functionally complete, and are generally not suitable for production use. However, these features are included as a customer convenience and to provide the feature with wider exposure.

Customers may find these features useful in a non-production environment. Customers are also free to provide feedback and functionality suggestions for a technology preview feature before it becomes fully supported. Erratas will be provided for high-severity security issues.

During the development of a technology preview feature, additional components may become available to the public for testing. It is the intention of Red Hat to fully support technology preview features in a future release.


Systemtap provides free software (GPL) infrastructure to simplify the gathering of information about the running Linux system. This assists diagnosis of a performance or functional problem. With the help of systemtap, developers no longer need to go through the tedious and disruptive instrument, recompile, install, and reboot sequence that may be otherwise required to collect data.

Frysk GUI

The goal of the frysk project is to create an intelligent, distributed, always-on system monitoring and debugging tool that allows developers and system administrators to:

  • monitor running processes and threads (including creation and destruction events)

  • monitor the use of locking primitives

  • expose deadlocks

  • gather data

  • debug any given process by choosing it from a list or allowing frysk to open a source code (or other) window on a process that is crashing or misbehaving

In Red Hat Enterprise Linux 4 Update 5 the frysk graphical user interface is a technology preview, whereas the frysk command line interface is fully supported.

Kernel Notes

This section lists updates related to the kernel.

Generic Kernel Notes

  • CONFIG_SERIAL_8250_MANY_PORTS has been increased to 64.

  • sata_nv module now supports diskdump.

  • acpiphp driver now supports ACPI-based hotplugs for bridged adapters.

  • (x86;x86_64) Added paravirtualization guest support

  • CIFS (Common Internet file system) has been upgraded to version 1.45

Platform-Specific Updates

  • Added capabilities for disabling MSI for SHPC (Standard Hot Plug Controllers) on PXH6700 and PHX6702 systems; these systems will use the legacy intX mode instead

  • Intel ICH9 chipsets are now supported

  • PowerNow! (with new frequency control) is now supported on the H206 processor

  • Timer skew issue on PowerNow! drivers is now fixed

  • Quad-core processors are now supported

  • RDTSCP (Read Time-Stamp Counter Pair), an instruction that provides better resolution in reading a processor's time stamp, is now supported

  • MCE Thresholding is now supported on AMD 0x10 processors

  • PCI-Express is now supported for the SGI Altix platform

  • SHUB2 is now supported

Changes to Drivers and Hardware Support

  • Sealevel 8-port serial cards are now supported

  • Added a new PWC (Philips Web Cam) driver that supports a wider range of webcam models

  • IBM Advanced Management Module 2 has been added to the USB storage whitelist for USB devices with multiple LUNs (Logical Unit Numbers)

  • EDAC (Error Detection and Correction) is now supported on the AMD Opteron

  • Updated Alsa driver to version 1.0.9

  • Added Alsa support for Broadwater platforms

  • Updated LMSensors smsc47b397 driver

  • Updated ixgb driver to version 1.0.109-k2

  • Updated r8169 network driver to version 2.2LK

  • Pathscale IB adapter is now supported

  • Added qla4xxx driver to support Qlogic iSCSI hardware initiator. Also added qla3xxx driver to provide LAN connections on the same hardware.

  • Updated Infiniband support to OFED 1.1

  • Updated e1000 driver to version 7.2.7-k2 to support Intel Pro/1000 PT adapter, ICH8 LAN, and Intel Dual Port 1Gb Ethernet PCI-Express adapter

  • Updated BNX2 driver to version 1.4.43-rh

  • Updated Broadcom TG3 driver to version 3.64-rh to support Broadcom BCM5787M, the Broadcom 5715 PCIExpress adapter and the Broadcom 5704S chip

  • Updated ipr driver to support SAS/SATA

  • LSI Logic SAS ZCR is now supported

  • sata driver now supports ULi M5289 SATA controller

  • Updated cciss driver

  • Updated qla2xx driver to support SLIM expansion card on JS21

  • Updated MPTSAS driver to version 3.02.73rh

  • Updated the LSI MegaRAID driver

  • 8139cp networking driver now supports netdump; this enables fully virtualized Red Hat Enterprise Linux 4 guests to run netdump

( x86 )