Red Hat Enterprise Linux 5 Beta 2
Posted on: 11/17/2006 12:17 PM
Red Hat Enterprise Linux 5 Beta 2 has been released:
Red Hat is pleased to announce the availability of Red Hat Enterprise Linux 5 Beta 2 (kernel 2.6.18-1.2747.el5). Red Hat Enterprise Linux 5 Beta 2 is a preview of the next generation of Red Hat's comprehensive suite of enterprise operating systems and products, designed for mission-critical enterprise computing and certified by top enterprise hardware and software vendors.
This announcement includes details on obtaining the beta software, reporting bugs, communicating with Red Hat and other testers via mailing lists during the beta period, and certifying hardware.
Red Hat Enterprise Linux 5 is still in development and therefore the contents of the media kit, the implemented features, and the supported configurations are subject to change before the release of the final product. The supplied beta packages and CD images are intended for testing purposes only. Remember that this early access software is not supported and is not intended for production environments. Do not publish any benchmark or performance results based on this beta release. Upgrading from beta releases to the GA product will not be supported.
Red Hat Enterprise Linux 5 Features
Red Hat Enterprise Linux 5 has been developed in close cooperation with the Fedora Core 6 and the upstream community. This is the first Red Hat Enterprise Linux release that includes Xen-based open source virtualization technology. The Red Hat Enterprise Linux 5 Beta 2 release contains virtualization support on the x86 and x86-64 architectures as well as a technology preview of Xen for Itanium 2. We are particularly interested in your testing feedback on the virtualization technology.
Focus areas for Red Hat Enterprise Linux 5 Beta 2 testing include the following:
* Virtualization (Para/full, 32/64-bit x86, libvirt, virt-manager)
* SELinux MLS support (EAL4+ / LSPP)
* SELinux Troubleshooter (Greatly simplifies administration)
* File Integrity Checking (aide)
* Audit (Powerful new search / reporting tools; unique real time interface)
* Network storage (Autofs, FS-Cache (Tech Preview; see below) / NFS persistent local cache, NFSv4, iSCSI)
* Integrated directory security (Smart card login with PKI / Kerberos authentication)
* Desktop (GNOME, X.Org 7.1, Laptop support features)
* Stateless Linux (Desktop / Server / Virtualized / Infrastructure) (Tech Preview; see below)
* New Driver Update Program (Improved delivery for supported drivers and for new drivers (including 3rd party drivers))
* Enhanced development tools (Systemtap, Frysk) (Tech Preview; see below)
* Enhanced large SMP support (Big kernel lock removal, etc.)
* Multi-Core Support (Quad core processor support)
* Single Node / Guest GFS2 (Tech Preview; see below)
* Kexec / Kdump (Replacing Diskdump and Netdump)
* Installer improvements
* Enhanced IPv6 support (Conformance improvements, IPv6-Ready Phase 2 targeted, Multiple routing tables, and robustness and performance improvements)
* IPSEC enhancements
* I/OAT, IPv4 / IPv6 fragmentation offload optimized buffer management
* Improved ACPI support, suspend to disk
* Block device data encryption support
* Root device MPIO support
* Dynamically switchable per-queue I/O schedulers
* Enhanced pipe buffering (Circular buffers)
* Integrated multi-media support (MP3, Ogg Vorbis, Ogg Theora; other formats TBD in final product)
* Enhanced plug and play hardware support (Cameras, etc.)
* Enhanced graphics using AIGLX/Compiz (e.g. Fading, transparency, etc.) (Tech Preview; see below)
* Network Manager (Automatic network configuration)
* Samba (Improved Microsoft (tm) Active Directory integration)
* Yum/Pup updater for RHN
* New Clustering infrastructure, Distributed Lock Manager (Single node / Guest)
* Broad range of new HW support
The following features are included in Red Hat Enterprise Linux 5 as Technology Previews. Technology Preview features are included in Red Hat Enterprise Linux releases but are not supported except with erratas for high-priority security issues. Once a Technology Preview has received adequate partner and community testing, it will become a fully supported feature in an upcoming release of Red Hat Enterprise Linux. Throughout the development cycle of a Technology Preview feature, additional portions of the feature may be made available publicly for testing. See the Red Hat Enterprise Linux 5 Release Notes for more information about these Technology Previews.
- Xen for Itanium 2
- Stateless Linux enablers. Stateless Linux is a new way of thinking about how a system is to be run and managed and is designed to simplify provisioning and management of large numbers of systems by making them easily replaceable. Included in Red Hat Enterprise Linux 5 are a substantial number of enablers in various system utilities, primarily in support of read-only root configurations. The tools used to provision system images are still under development. For information on how to utilize these stateless capabilities, refer to the Release Notes.
- GFS2. GFS2 is an evolutionary advancement based on the GFS file system. While fully functional, GFS2 has not yet completed all required qualification testing. GFS, which has been in production for 5 years, is being provided with this release and is fully supported for non-clustered data file systems (except for root and boot), as well as in clustered file system configurations on shared storage when the cluster infrastructure is present.
- FS-Cache. FS-Cache is a local caching facility for remote file systems that allows users to cache NFS data on a locally mounted disk.
- Compiz. Compiz is an OpenGL-based compositing window manager. In addition to regular window management, compiz also acts as a compositing manager. In this role, compiz coordinates and synchronizes the overall desktop redrawing to provide a smoother desktop experience with less flicker and a more solid feel.
- AIGLX. AIGLX is a feature of the otherwise fully supported X server. It aims to enable GL-accelerated effects on a standard desktop. The project consists of a lightly modified X server, an updated Mesa package that adds new protocol support, and a version of metacity with a composite manager. By installing these components, you can have GL-accelerated effects on your desktop with very few changes and have the ability to turn them on and off at will without replacing your X server.
- Ext3 Enhancement. The EXT3 file system capacity has been extended as a Technology Preview beyond 8TB to a maximum of 16TB.
- 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, and debug any given process by either choosing it from a list or by accepting frysk's offer to open a source code or other window on a process that is in the process of crashing or that has been misbehaving in certain user-definable ways. In Red Hat Enterprise Linux 5, the frysk graphical user interface is a Technology Preview; the frysk command line interface is fully supported.
- Systemtap. 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. Systemtap eliminates the need for the developer to go through the tedious and disruptive instrument, recompile, install, and reboot sequence that may be otherwise required to collect data.
- Kannada. Kannada is a newly supported Indian language.
- Dogtail. Dogtail is a GUI test tool and automation framework written in Python that uses Accessibility (A11Y1) technologies to communicate with desktop applications.
New Packaging Structure in Red Hat Enterprise Linux 5
The architecture of the media kit in Red Hat Enterprise Linux 5 Beta 2has changed from previous releases of Red Hat Enterprise Linux. Thenumber of different variants and trees (ISOs) has been reduced to:
* Red Hat Enterprise Linux 5 Server
* Red Hat Enterprise Linux 5 Client (Desktop)
Red Hat Enterprise Linux Client is available for the x86 and x86-64 architectures only.
The trees contain repositories for a number of options that provide additional functionality over the core distribution.
Red Hat Enterprise Linux Server variant:
* Red Hat Enterprise Linux. Default multi-purpose server operating system including virtualization capabilities. In addition to a non-virtualizing kernel, Red Hat Enterprise Linux 5 includes a virtualizing host kernel (Dom0) and a para-virtualized guest kernel (DomU).
The one Server option is:
+ Red Hat Enterprise Linux Virtualization Platform Option. Datacenter virtualization operating system including clustering and cluster storage.
Red Hat Enterprise Linux Client variant:
* Red Hat Enterprise Linux Desktop. Default multi-purpose client. Full suite of desktop applications including Evolution and OpenOffice (not available on the Server).
The two Desktop options are:
+ Workstation Option. Add-on option for engineering and development workstations. Provides Engineering Workstation and Developer packages.
+ DualOS Option. Virtualization support add-on option.
Accessing the Software
Red Hat Enterprise Linux 5 Beta 2 is available to existing Red Hat Enterprise Linux subscribers via RHN. The beta channels will automatically appear in your account. Installable binary and source ISO images are available via Red Hat Network at: https://rhn.redhat.com/network/software/download_isos_full.pxt
You will be required to login using a valid RHN account with active entitlements. If you would like to test Beta 2 but do not have an active Red Hat Enterprise Linux entitlement, contact your local Red Hat representative.
Red Hat plans to update packages as necessary on RHN post Beta 2 release. Check your RHN account regularly for updates.
Installing the Software / Installation Numbers
The ISO images contain the Red Hat Enterprise Linux 5 core and optional components. Red Hat Enterprise Linux 5 requires users to enter an Installation Number that guides the Installer to include the correct components. In the final release, the Installation Number will be associated with your subscription entitlement. If you plan to install multiple systems using a Kickstart file, you can embed an Installation Number in that Kickstart file.
If an Installation Number is not entered, a core Server or Desktop will be installed by default. Additional functionality can be added manually or via RHN at a later time.
The following installation numbers should be used for Beta 2 and supercede those in the redhat-release-notes package:
* Red Hat Enterprise Linux (Server including virtualization):
+ Red Hat Enterprise Linux Virtualization Platform:
* Red Hat Enterprise Linux Desktop:
+ Red Hat Enterprise Linux Desktop + Workstation Option:
+ Red Hat Enterprise Linux Desktop + Workstation + DualOS Option
+ Red Hat Enterprise Linux Desktop + DualOS Option (Virtualization):
Red Hat Enterprise Linux 5 Beta testers who have assigned Technical Account Managers (TAMs) and/or Technical Partner Managers should report all bugs with this beta release using your current Issue Tracker account.
All other beta users should report bugs using Red Hat's Bugzilla. To report and query for bugs in this Beta release, you need a Bugzilla account with access to the "Red Hat Enterprise Linux Public Beta" product.
To report a bug via Bugzilla:
1. Login to the Bugzilla home page at http://bugzilla.redhat.com.
If you don't have an existing account, simply create one by going to this page: https://bugzilla.redhat.com/bugzilla/createaccount.cgi
2. On the Bugzilla home page, choose the "New" tab. Proceed to Step 3, "Choosing Your Product" by clicking that button at the bottom of the page.
3. Choose Product "Red Hat Enterprise Linux Public Beta".
4. Choose Version "rhel5-beta2".
5. Choose the component against which you wish to report a problem, such as kernel, glibc, etc. If you do not know the component or want to file a bug against the general product, choose "distribution" as the component.
6. Choose the platform, such as: "All", "x86_64", etc.
7. Provide the information about the problem you're reporting by entering information in the appropriate fields. In the Summary field, provide a clear and descriptive abstract of the issue. In the Description field, state clearly that you are using a *Beta 2* package and provide the full package versions of any components you are experiencing problems with (as packages may be updated).
8. Check to make sure that all information is accurate and click the "Commit" button to submit your problem report.
The Red Hat Enterprise Linux 5 documentation can be found at: http://www.redhat.com/docs/manuals/enterprise/RHEL-5-manual/index.html
The Release Notes are also attached to this announcement and are on your Red Hat Enterprise Linux 5 installed system in the redhat-release-notes package.
- IA32 Execution Layer. IA32 Execution Layer users should note a change regarding the installation of the IA32 Execution Layer CD for Beta 2 only. Install the following components in this order:
+ Red Hat Enterprise Linux 5 operating system
+ IA32EL from the Supplementary CD
+ bash.i386 and libtermcap.i386 from the compat-layer CD
+ the remaining 32-bit packages from the compat-layer CD
You can view additional known issues in the Release Notes and in the Red Hat Knowledgebase system at: http://kbase.redhat.com/faq/topten_105_0.shtm
For Red Hat Enterprise Linux 5 and subsequent updates, the announcement mailing list is rhelv5-announce redhat com. Subscribe using the web-based mailing list interface at: http://www.redhat.com/mailman/listinfo/rhelv5-announce
Red Hat has created a public mailing list for general discussion of the Red Hat Enterprise Linux 5 (Tikanga) Beta releases. To subscribe to the list, send mail to rhelv5-beta-list-request redhat com with 'subscribe' in the subject line. Leave the body empty. Or subscribe using the web-based mailing list interface at: https://www.redhat.com/mailman/listinfo/rhelv5-beta-list/
Thank you for your interest in the Red Hat Enterprise Linux 5 beta program. We look forward to working with you to ensure a high quality release.
The Red Hat Enterprise Linux Team
Copyright (c) 2006 Red Hat, Inc. and others
Copyright (c) 2006 Red Hat, Inc. and others
The following topics are covered in this document:
o Installation-Related Notes
o Technology Previews
o Known Issues
o General Information
o Kernel Notes
For late-breaking information on Red Hat Enterprise Linux 4.92 that did
not appear in these Release Notes, refer to the Red Hat Knowledgebase at
the following URL:
The following section includes information specific to the installation of
Red Hat Enterprise Linux and the Anaconda installation program.
In order to upgrade an already-installed Red Hat Enterprise Linux, 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 4.92 or to perform an upgrade from the latest updated version of Red
Hat Enterprise Linux 4 to Red Hat Enterprise Linux 4.92.
If you are copying the contents of the Red Hat Enterprise Linux 4.92
CD-ROMs (in preparation for a network-based installation, for example) be
sure to 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.
Note that the minimum RAM required to install Red Hat Enterprise Linux
4.92 has been raised to 1GB; the recommended RAM is 2GB. If a machine has
less than 1GB RAM, the installation process may hang.
ISO Contents and Registration
The architecture of the media kit in Red Hat Enterprise Linux 4.92 has
changed from previous versions of Red Hat Enterprise Linux. The number of
different variants and ISO images have been reduced to two:
o Red Hat Enterprise Linux 4.92 Server
o Red Hat Enterprise Linux 4.92 Client
The trees contain repositories for a number of options that provide
additional functionality over the core distribution:
Red Hat Enterprise Linux 4.92 Server
o Red Hat Enterprise Linux -- default multi purpose server operating
system containing virtualization with support for up to 4 virtual
o Red Hat Enterprise Linux Virtualization Platform -- datacenter
virtualization operating system including clustering and cluster
Red Hat Enterprise Linux 4.92 Client
o Red Hat Enterprise Linux Desktop -- Knowledge-worker Desktop product
o Workstation Option -- add-on option for engineering and development
o Virtualization Option -- add-on option for virtualization support
With optional content in the same tree or ISO image, it is important to
avoid a mismatch between the components offered for installation and those
covered by the subscription. Such a mismatch would result in an increased
exposure to bug and vulnerability risks.
In order to ensure that the components offered are in sync with the
subscription, Red Hat Enterprise Linux 4.92 requires entering an
Installation Number that will be used to configure the installer to offer
the right package set.
If you skip entering the Installation Number, this will result in a core
Server or Desktop installation. Additional functionality can then be added
manually at a later time.
Default numbers that can be used are:
o Red Hat Enterprise Linux (Server ): 31cfdaf1358c25da
o Red Hat Enterprise Linux (Server + Virtualization): 2515dd4e215225dd
o Red Hat Enterprise Linux Virtualization Platform: 49af89414d147589
o Red Hat Enterprise Linux Desktop: 660266e267419c67
o Red Hat Enterprise Linux Desktop / Virtualization Option:
o Red Hat Enterprise Linux Desktop / Workstation Option:
o Red Hat Enterprise Linux Desktop / Workstation / Virtualization
In Red Hat Enterprise Linux 4.92, the Subversion version control system is
linked against Berkeley DB 4.3. If you are upgrading from Red Hat
Enterprise Linux 4 and any Subversion repositories have been created on
the system which use the Berkeley DB backend "BDB" (rather than the pure
file system-based "FSFS" backend), special care must be taken to ensure
the repositories can be accessible after the upgrade. The following
process must be performed on the Red Hat Enterprise Linux 4 system, prior
to upgrading to Red Hat Enterprise Linux 4.92:
1. Shut down any running processes and ensure that no processes can
access the repository (for example, httpd, svnserve or any local users
with direct access).
2. Create a backup of the repository; for example:
svnadmin dump /path/to/repository | gzip gt; repository-backup.gz
3. Run the svnadmin recover command on the repository:
svnadmin recover /path/to/repository
4. Delete any unused log files in the repository:
svnadmin list-unused-dblogs /path/to/repository | xargs rm -vf
5. Delete any remaining shared-memory files in the repository:
rm -f /path/to/repository/db/__db.0*
Technology Previews are features that are not currently supported, but are
made available in a release. Their described functionalities can be
tested; however, the only support to be provided for Technology Previews
are erratas for high-priority security issues.
Throughout its development, additional portions of a Technology Preview
may also become available to the public for testing. It is the intention
of Red Hat to fully support a technology preview in an upcoming minor or
Included in this beta of Red Hat Enterprise Linux 4.92 are
enabling infrastructure pieces for Stateless Linux. Stateless
Linux is a new way of thinking about how a system is to be run and
managed, designed to simplify provisioning and management of large
numbers of systems by making them easily replaceable. This is
primarily accomplished by establishing prepared system images
which get replicated and managed across a large number of
stateless systems, running the operating system in a read-only
In its current state of development, the Stateless features are
subsets of the intended goals. As such, the capability is being
labeled as a technology preview.
The following is a list of the initial capabilities included in
Red Hat Enterprise Linux 4.92 beta:
o running a stateless image over NFS
o running a stateless image via loopback over NFS
o running on iSCSI
It is currently not possible to run Stateless Linux on a local
file system with changes synchronized from a master server, due to
required kernel changes.
It is highly recommended that those interested in testing
stateless code read the HOWTO at
http://fedoraproject.org/wiki/StatelessLinuxHOWTO and join
stateless-list redhat com
GFS2 is an evolutionary advancement based on the GFS file system.
While fully functional, GFS2 is not yet considered
production-ready. GFS, which has been in production for 5 years,
is being provided with this release and is fully supported for
non-clustered data file systems (except for root and boot), as
well as in clustered file system configurations on shared storage
when the cluster infrastructure is present. GFS2 is targeted to
move to a fully supported status in a subsequent Red Hat
Enterprise Linux 4.92 update. There is also an in-place conversion
utility, gfs2_convert, which can update the meta data of a GFS
file system, converting it to a GFS2 file system.
FS-Cache is a local caching facility for remote file systems; it
allows users to cache NFS data on a locally mounted disk. To set
up the FS-Cache facility, install the cachefilesd RPM and refer to
the instructions in /usr/share/doc/cachefilesd-lt;versiongt;/README.
Replace lt;versiongt; with the corresponding version of the
cachefilesd package installed.
Compiz is an OpenGL-based compositing window manager. In addition
to regular window management, compiz also acts as a compositing
manager. In this role, compiz coordinates and synchronizes the
overall desktop redrawing to provide a smoother desktop experience
with less flicker and a more solid feel.
Compiz uses 3D hardware acceleration to render effects such as
live thumbnail windows and window drop shadows, as well as
animated window minimizing and transitions between virtual
Due to limitations in the current rendering architecture, compiz
cannot work correctly with direct rendering OpenGL applications or
applications using the Xv extension. Such applications will
exhibit harmless rendering artifacts; because of this, the feature
is currently not supported fully.
Enhancement for Ext3
In Red Hat Enterprise Linux 4.92, the EXT3 file system capacity
has been extended beyond 8TB to a maximum of 16TB. This capability
is being included as a technology preview, and is targeted for
full support in a future release of Red Hat Enterprise Linux 4.92.
o bind upgrade error: when upgrading bind, a No such file or directory
error may occur. This is caused by an installation sequencing bug,
which will be addressed prior to GA. To work around this, login as
root and run /usr/sbin/bind-chroot-admin --enable (if you have
installed the bind-chroot package) or /usr/sbin/bind-chroot-admin
--sync (if you have installed the caching-nameserver package).
o caching-nameserver upgrade error: when upgrading caching-nameserver,
the logs display an invalid context error. This is caused by a
dependency issue with the selinux-policy package, which will be
addressed prior to GA. To work around this, login as root and run
o Kernel module packages (kmods) can only be built with kABI
dependencies if they are built on a system for which both the
kernel-devel and the corresponding kernel package are installed. As
such, it is currently not possible to build kABI-enhanced kmods
against uninstalled kernels. This limitation will be addressed prior
o Host bus adapters that use the MegaRAID driver must be set to operate
in "Mass Storage" emulation mode, not in "I2O" emulation mode. To do
this, perform the following steps:
1. Enter the MegaRAID BIOS Set Up Utility.
2. Enter the Adapter settings menu.
3. Under Other Adapter Options, select Emulation and set it to Mass
If the adapter is incorrectly set to "I2O" emulation, the system will
attempt to load the i2o driver. This will fail, and render the adapter
Previous Red Hat Enterprise Linux releases generally do not attempt to
load the I20 driver before the MegaRAID driver. Regardless of this,
the hardware should always be set to "Mass Storage" emulation mode
when used with Linux.
o ext3 / jbd kernel panic: heavy I/O to file systems where the block
size is smaller than the page size may cause jbd to crash.
This issue is being investigated and will be resolved in GA.
o Virtualization guest installation error: Installing a paravirt guest
on a system with a default ethernet connection on eth1 results in a No
Driver Found error. To work around this, set eth0 as the default
This issue is being investigated and will be resolved in GA.
o Anaconda incorrectly selects vesa driver: when Red Hat Enterprise
Linux 4.92 is installed in text-only mode on a system with a geforce
5200-based video card, the vesa driver will be selected. This is
incorrect, and will cause the screen to go blank once you run
system-config-display. This issue will be resolved in GA.
To work around this, open xorg.conf and change the line Driver "vesa"
to Driver "nv".
o Virtualization paravirt guest installation failure: attempting to
install a paravirt guest on a system where SELinux is enabled will
fail. This issue is being investigated and will be resolved in GA.
To work around this, turn off SELinux before installing a paravirt
o Virtualization guest boot bug: when you install a fully virtualized
guest configured with vcpus=2, the fully virtualized guest may take an
unreasonably long time to boot up. This issue is being investigated
and will be resolved in GA.
To work around this, disable the guest ACPI by using the kernel
parameters acpi=strict or acpi=static for the virtualized kernel
during grub boot. Note that this workaround may not address the issue
on some systems.
o X Display Server crashes with virtualized kernel: when booting with
the virtualized kernel, the X server will crash upon startup. This
issue is being investigated and will be resolved in GA.
To work around this, edit /etc/X11/xorg.conf by adding the following
line in the ServerLayout section:
Option "Int10Backend" "lt;modegt;"
Replace lt;modegt; with either vm86 (the default when running a bare Linux
kernel) or x86emu (when running a virtualized kernel). This will allow
runtime selection of the int10 execution method.
o The openmpi stack quits working entirely: Red Hat Enterprise Linux
4.92 includes openmpi-1.1.1-4.el5 (from the OFED 1.1 distribution)
which has been discovered to eventually quit working entirely. This
happens after the openmpi stack works as expected for a varying amount
This issue is being investigated and will be resolved in GA. For
updated versions of openmpi, please check
o Windows Server 2003 guest install bug: Installing Windows Server 2003
as a guest on a fully virtualized Red Hat Enterprise Linux 4.92 system
ends unexpectedly after completing the first stage of installation.
When this happens, the graphical console window closes, and the guest
disappears from the Virtual Machine Manager's list of machines,
resulting in a Broken pipe error.
This issue is being investigated and will be resolved in GA. To work
around this, use the following command at the terminal:
xm create /etc/xen/lt;name of guest machinegt;
Afterwards, open the virtual machine.
o Windows Server 2003 guest stage 2 install bug: when attempting to
create a fully virtualized Windows Server 2003 from a CD / DVD, the
second stage of the guest install will not resume upon reboot.
This issue is being investigated and will be resolved in GA. To work
around this, edit /etc/xen/lt;name of guest machinegt; by appending
'phy:/dev/dvd,hdc:cdrom,r' to the disk line. As such, the disk line
should now read as follows:
disk = [ 'file:/opt/win2003-sp1-20061107,hda,w', 'phy:/dev/dvd,hdc:cdrom,r']
This section contains general information not specific to any other
section of this document.
Red Hat Enterprise Linux 4.92 features virtualization capabilities
for i686 and x86-64, as well as the software infrastructure needed
to manage a virtualized environment.
The implementation of virtualization in Red Hat Enterprise Linux
4.92 is based on the hypervisor, which facilitates extremely low
overhead virtualization through paravirtualization. With Intel
Virtualization Technology or AMD AMD-V capable processors,
virtualization in Red Hat Enterprise Linux 4.92 allows operating
systems to run unmodified in fully virtualized mode.
Virtualization on Red Hat Enterprise Linux 4.92 also features the
o Libvirt, a library that provides a consistent, portable API
for managing virtual machines.
o Virtual Machine Manager, a graphical utility for monitoring
and managing virtual machines.
o Virtual machine support in the installer, including the
ability to kickstart virtual machines.
Red Hat Network also supports virtual machines.
Web Server Packaging Changes
Red Hat Enterprise Linux 4.92 now includes version 2.2 of the
Apache HTTP Server. This release brings a number of improvements
over the 2.0 series, including:
o improved caching modules (mod_cache, mod_disk_cache,
o a new structure for authentication and authorization support,
replacing the authentication modules provided in previous
o support for proxy load balancing (mod_proxy_balancer)
o support for handling large files (namely, greater than 2GB)
on 32-bit platforms
The following changes have been made to the default httpd
o The mod_cern_meta and mod_asis modules are no longer loaded
o The mod_ext_filter module is now loaded by default.
If upgrading from a previous release of Red Hat Enterprise Linux,
the httpd configuration will need to be updated for httpd 2.2. For
more information, refer to
Any third-party modules compiled for httpd 2.0 must be rebuilt for
Version 5.1 of PHP is now included in Red Hat Enterprise Linux
4.92, which includes a number of changes to the language along
with significant performance improvements. Some scripts might need
to be edited for use with the new version; please refer to the
link below for more information on migrating from PHP 4.3 to PHP
The /usr/bin/php executable is now built using the CLI
command-line SAPI, rather than the CGI SAPI. Use /usr/bin/php-cgi
for CGI SAPI. The php-cgi executable also includes FastCGI
The following extension modules have been added:
o The mysqli extension, a new interface designed specifically
for MySQL 4.1. This is included in the php-mysql package.
o date, hash, Reflection, SPL and SimpleXML (built-in with the
o pdo and pdo_psqlite (in the php-pdo package)
o pdo_mysql (in the php-mysql package)
o pdo_pgsql (in the php-pgsql package)
o pdo_odbc (in the php-odbc package)
o soap (in the php-soap package)
o xmlreader and xmlwriter (in the php-xml package)
o dom (replacing the domxml extension in the php-xml package)
The following extension modules are no longer included:
The PEAR Framework
The PEAR framework is now packaged in the php-pear package. Only
the following PEAR components are included in Red Hat Enterprise
Building kmod kernel module packages with kernel ABI dependency tracking
On Red Hat Enterprise Linux 4.92, it is possible to build updated
kernel module packages that depend upon the current kernel ABI
version and not on a specific kernel release number. This
facilitates building kernel modules that can be used against a
range of Red Hat Enterprise Linux 4.92 kernels, rather than a
single release. The project website at
http://www.kerneldrivers.org/ contains more information about
the packaging process, as well as several examples.
Encrypted Swap Partitions and Non-root File Systems
Red Hat Enterprise Linux 4.92 now provides basic support for
encrypted swap partitions and non-root file systems. To use these
features, add the appropriate entries to /etc/crypttab and
reference the created devices in /etc/fstab.
Below is a sample /etc/crypttab entry:
my_swap /dev/hdb1 /dev/urandom swap,cipher=aes-cbc-essiv:sha256
This creates the encrypted block device /dev/mapper/my_swap, which
can be referenced in /etc/fstab.
Below is a sample /etc/crypttab entry for a file system volume:
my_volume /dev/hda5 /etc/volume_key cipher=aes-cbc-essiv:sha256
The /etc/volume_key file contains a plaintext encryption key. You
can also specify none as the key file name, at which the system
will ask for the encryption key during boot instead.
It is recommended to use LUKS for setting up file system volumes.
To do this, follow these steps:
1. Create the encrypted volume using cryptsetup luksFormat.
2. Add the necessary entry to /etc/crypttab.
3. Set up the volume manually using cryptsetup luksOpen (or
4. Create a file system on the encrypted volume.
5. Add the necessary entry to /etc/fstab.
mount and umount
The mount and umount commands no longer directly support NFS;
there no longer is a built-in NFS client. A separate nfs-utils
package, which provides /sbin/mount.nfs and /sbin/umount.nfs
helpers, must be installed for this.
CUPS printer browsing
CUPS printer browsing over a local subnet can be configured using
the graphical tool system-config-printer. It can also be done
using the CUPS web interface, http://localhost:631/.
To use directed broadcasts for printer browsing between subnets,
open /etc/cups/cupsd.conf on the clients and change BrowseAllow
@LOCAL to BrowseAllow ALL.
This section includes information on language support under Red Hat
Enterprise Linux 4.92.
SCIM (Smart Common Input Method) has replaced IIIMF as the input
method system for Asian and other languages in this release. The
default GTK Input Method Module for SCIM is provided by
scim-bridge; in Qt, it is provided by scim-qtimm.
Below are the default trigger hotkeys for different languages:
o All languages: Ctrl-Space
o Japanese: Zenkaku-Hankaku or Alt-`
o Korean: Shift-Space
If SCIM is installed, it runs by default for all users.
SCIM is installed by default for most Asian installations.
Otherwise, you can use the package manager (pirut) to install
additional language support using the "Languages" component, or
run this command:
su -c 'yum groupinstall lt;languagegt;-support'
In the command above, lt;languagegt; can be either Assamese, Bengali,
Chinese, Gujarati, Hindi, Japanese, Kannada, Korean, Malayalam,
Marathi, Oriya,Punjabi, Sinhala, Tamil, Thai, or Telugu.
A new user configuration tool called im-chooser has been added,
which allows you to easily disable or enable the usage of input
methods on your desktop. So if SCIM is installed but you do not
wish to run it on your desktop, you can disable it using
At X startup, xinput.sh now sources ~/.xinputrc or
/etc/X11/xinit/xinputrc instead of searching config files under
~/.xinput.d/ or /etc/xinit/xinput.d/.
Pango Support in Firefox
Firefox in Red Hat Enterprise Linux 4.92 is built with Pango,
which provides better support for certain scripts, such as Indic
and some CJK scripts.
To disable the use of Pango, set MOZ_DISABLE_PANGO=1 in your
environment before launching Firefox.
Support is now available for synthetic emboldening of fonts that
do not have a bold face.
New fonts for Chinese have been added: AR PL ShanHeiSun Uni
(uming.ttf) and AR PL ZenKai Uni (ukai.ttf). The default font is
AR PL ShanHeiSun Uni, which contains embedded bitmaps. If you
prefer outline glyphs, you can add the following section in your
lt;test name="family" compare="eq"gt;
lt;stringgt;AR PL ShanHeiSun Unilt;/stringgt;
lt;edit name="embeddedbitmap" mode="assign"gt;
gtk2 IM submenu
The Gtk2 context menu IM submenu no longer appears by default. You
can enable it on the command line with the following command:
gconftool-2 --type bool --set '/desktop/gnome/interface/show_input_method_menu' true
Support for text installation on CJK
CJK (Chinese, Japanese, and Korean) rendering support has been
removed from the Anaconda text installation. The text installation
method is being deprecated in the long term, as the GUI
installation, VNC and kickstart methods are preferred.
The following packages are deprecated and scheduled for removal in
Red Hat Enterprise Linux:
These packages are being deprecated in favor of the gtk2 stack,
which offers better functionality particularly in terms of
internationalization and font handling.
CJK input on console
If you need to display Chinese, Japanese, or Korean on the
console, you need to setup a framebuffer. To do this, install bogl
and bogl-bterm, and run bterm on the framebuffer. Note that the
kernel framebuffer module depends on the graphics chipset in your
This section notes the differences between 2.6.9 (on which Red Hat
Enterprise Linux 4 is based) and 2.6.18 (which Red Hat Enterprise Linux
4.92 will inherit) as of July 12, 2006. Additional features which we are
currently working on upstream (for example, virtualization) that will
appear late in 2.6.18 or 2.6.19 are not highlighted here. In other words,
this list only shows what is already included in the upstream Linus tree;
not what is currently in development. Consequently, this list is not a
final, or complete list of the new Red Hat Enterprise Linux 4.92 features,
although it does give a good overview of what can be expected. Also, note
that this section only picks out highlights of upstream changes, and as
such it is not fully comprehensive. It does not include mention of several
low-level hardware support enhancements and device driver info.
The following is a good source for a next level-of-detail view:
Performance / Scalability
o Big Kernel Lock preemption (2.6.10)
o Voluntary preemption patches (2.6.13) (subset in Red Hat
Enterprise Linux 4)
o Lightweight user-space priority inheritance (PI) support for
futexes, useful for real-time applications (2.6.18)
o ref: http://lwn.net/Articles/178253/
o New 'mutex' locking primitive (2.6.16)
o High resolution timers (2.6.16)
o In contrast to the low-resolution timeout API
implemented in kernel/timer.c, hrtimers provide finer
resolution and accuracy depending on system
configuration and capabilities. These timers are
currently used for itimers, POSIX timers, nanosleep and
precise in-kernel timing.
o Modular, on-the-fly switchable I/O schedulers (2.6.10)
o This was adjustable only by boot option in Red Hat
Enterprise Linux 4 (also system-wide instead of
o New Pipe implementation (2.6.11)
o 30-90% performance improvement in pipe bandwidth
o circular buffer allows more buffering than blocking
o "Big Kernel Semaphore": turns the Big Kernel Lock into a
o reduces latency by breaking up long lock hold times and
adding voluntary preemption
o X86 "SMP alternatives"
o optimizes a single kernel image at runtime according to
the available platform
o ref: http://lwn.net/Articles/164121/
o kernel-headers package
o replaces the glibc-kernheaders package
o provides better suitability with the new headers_install
feature of the 2.6.18 kernel
o notable kernel header-related changes:
o removed lt;linux/compiler.hgt; header file, as it is no
o removed _syscallX() macros; user-space should use
syscall() from the C library instead
o removed lt;asm/atomic.hgt; and lt;asm/bitops.hgt; header
files; C compiler provides its own atomic built-in
functions better suitable for user-space programs
o content previously protected with #ifdef __KERNEL__
is now removed completely with the unifdef tool;
defining __KERNEL__ in order to view parts which
should not be visible to user-space is no longer
o removed the PAGE_SIZE macro from some
architectures, due to variance in page sizes;
user-space should be using sysconf (_SC_PAGE_SIZE)
o to provide better suitability for user-space, removed
several header files and header content
Generic Feature Additions
o kexec and kdump (2.6.13)
o netdump has been replaced by kexec and kdump, which
ensure faster boot-up and creation of reliable kernel
vmcores for diagnostic purposes. For more information
and configuration instructions, please refer to
(replace lt;versiongt; with the corresponding version of the
kexec-tools package installed).
o inotify (2.6.13)
o user interface for this is through the following
syscalls: sys_inotify_init, sys_inotify_add_watch, and
o Process Events Connector (2.6.15)
o reports fork, exec, id change, and exit events for all
processes to user-space.
o Applications that may find these events useful include
accounting / auditing (for example, ELSA), system
activity monitoring (for example, top), security, and
resource management (for example, CKRM). Semantics
provide the building blocks for features like
per-user-namespace, "files as directories" and versioned
o Generic RTC (RealTime Clock) subsystem (2.6.17)
o splice (2.6.17)
o new IO mechanism which avoids data copies when
transferring data between applications
o ref: http://lwn.net/Articles/178199/
o Block queue IO tracing support (blktrace): allows users to
view any traffic occurring on a block device queue, which
displays very detailed statistics of what disks are doing
File System / LVM
o ext3 block reservation (2.6.10) (in Red Hat Enterprise
o ext3 online resizing patches (2.6.10) (in Red Hat
Enterprise Linux 4)
o support for Extended Attributes in the body of large
inode in ext3: saves space and improves performance in
some cases (2.6.11)
o Device mapper multipath support (Red Hat Enterprise Linux 4)
o ACL support for NFSv3 and NFSv4 (2.6.13)
o NFS: supports large reads and writes on the wire (2.6.16)
o The Linux NFS client now supports transfer sizes of up
o FUSE (2.6.14)
o allows implementation of a fully functional file system
in a user-space program
o VFS changes
o The "shared subtree" patches have been merged. (2.6.15)
o ref: http://lwn.net/Articles/159077/
o Big CIFS update (2.6.15)
o features several performance improvements as well as
support for Kerberos and CIFS ACL
o autofs4: updated to provide direct mount support for
user-space autofs (2.6.18)
o cachefs core enablers (2.6.18)
o Address space randomization
o With these patches applied, the stack of each process
will begin at a random location, and the beginning of
the memory area used for mmap() (which is where shared
libraries go, among other things) will be randomized as
o Multilevel security implementation for SELinux (2.6.12)
o Audit subsystem
o support for process-context based filtering (2.6.17)
o more filter rule comparators (2.6.17)
o TCP/UDP getpeersec: enabled a security-aware application to
retrieve the security context of an IPSec security
association that a particular TCP or UDP socket is using
o Added several TCP congestion modules (2.6.13)
o IPv6: supports several new sockopt / ancillary data in
Advanced API (2.6.14)
o IPv4/IPv6: UFO (UDP Fragmentation Offload) Scatter-gather
o UFO is a feature wherein the Linux kernel network stack
will offload the IP fragmentation functionality of large
UDP datagram to hardware. This will reduce the overhead
of stack in fragmenting the large UDP datagram to
o Added nf_conntrack subsystem (2.6.15)
o The existing connection tracking subsystem in netfilter
can only handle ipv4. There were two choices present to
add connection tracking support for ipv6; either
duplicate all of the ipv4 connection tracking code into
an ipv6 counterpart, or (the choice taken by these
patches) design a generic layer that could handle both
ipv4 and ipv6 and thus requiring only one sub-protocol
(TCP, UDP, etc.) connection tracking helper module to be
written. In fact, nf_conntrack is capable of working
with any layer 3 protocol.
o RFC 3484 compliant source address selection (2.6.15)
o added support for Router Preference (RFC4191) (2.6.17)
o added Router Reachability Probing (RFC4191) (2.6.17)
o Wireless updates
o hardware crypto and fragmentation offload support
o QoS (WME) support, "wireless spy support"
o mixed PTK/GTK
o CCMP/TKIP support and WE-19 HostAP support
o BCM43xx wireless driver
o ZD1211 wireless driver
o WE-20, version 20 of the Wireless Extensions (2.6.17)
o added the hardware-independent software MAC layer, "Soft
o added LEAP authentication type
o Added generic segmentation offload (GSO) (2.6.18)
o can improve performance in some cases, though it needs
to be enabled through ethtool
o Added new per-packet access controls to SELinux, replacing
the old packet controls
o Added secmark support to core networking, to allow security
subsystems to place security markings on network packets.
o DCCPv6 (2.6.16)
Added Hardware Support
This section only enumerates the most generic features among many.
o x86-64 clustered APIC support (2.6.10)
o Infiniband support (2.6.11) (mostly in Red Hat Enterprise
o Hot plug
o added generic memory add/remove and supporting functions
for memory hotplug (2.6.15)
o hot plug CPU support for physically adding new
processors (hotplug disable / enable of already existing
CPUs is already supported)
o SATA/libata enhancements, additional hardware support (in Red
Hat Enterprise Linux 4)
o A completely reworked libata error handler; the result
of all this work should be a more robust SATA subsystem
which can recover from a wider range of errors.
o Native Command Queuing (NCQ), the SATA version of tagged
command queuing - the ability to have several I/O
requests to the same drive outstanding at the same time.
o Hotplug support (2.6.18)
o EDAC support (2.6.16) (in Red Hat Enterprise Linux 4)
o The EDAC goal is to detect and report errors that occur
within the computer system.
o Added a new ioatdma driver for the Intel(R) I/OAT DMA engine
NUMA (Non-Uniform Memory Access) / Multi-core
o Cpusets (2.6.12)
o Cpusets now provide a mechanism for assigning a set of
CPUs and Memory Nodes to a set of tasks. Cpusets
constrain the CPU and Memory placement of tasks only to
the resources within a task's current cpuset. These are
essential in managing dynamic job placement on large
o NUMA-aware slab allocator (2.6.14)
o This creates slabs on multiple nodes and manages slabs
in such a way that locality of allocations is optimized.
Each node has its own list of partial, free and full
slabs. All object allocations for a node occur from
node-specific slab lists.
o Swap migration (2.6.16)
o Swap migration allows the moving of physical location of
pages between nodes in a NUMA system while the process
o Huge pages (2.6.16)
o Added NUMA policy support for huge pages: the
huge_zonelist() function in the memory policy layer
provides a list of zones ordered by NUMA distance. The
hugetlb layer will walk that list looking for a zone
that has available huge pages but is also in the nodeset
of the current cpuset.
o Huge pages now obey cpusets.
o Per-zone VM counters
o provide zone-based VM statistics, which are necessary in
determining what state of memory a zone is in
o Netfilter ip_tables: NUMA-aware allocation. (2.6.16)
o Added a new scheduler domain for representing multi-core
with shared caches between cores. This makes it possible
to make smarter cpu scheduling decisions on such
systems, improving performance greatly for some cases.
o Power saving policy for the CPU scheduler: with
multicore/smt cpus, the power consumption can be
improved by leaving some packages idle whil