The Text Mode installation of Anaconda now offers the option of switching to Virtual Network Computing (VNC) to complete the installation.

Creating or using encrypted software RAID member disks (i.e. software RAID partitions) is not supported. However, creating encrypted software RAID arrays (e.g. /dev/md0) is supported.

The NFS default for RHEL5 is "locking". Therefore, to mount nfs shares from the %post section of anaconda, use the mount -o nolock,udp command to start the locking daemon before using nfs to mount shares.

When installing from CD-ROM or DVD-ROM on a system with an iBFT-configured network device, Anaconda will not include any iBFT-configured storage devices unless networking is configured. To enable networking for the installation, use the command linux updates=http://[any] at the installation boot prompt. Note that [any] can be replaced with any URL.

If your system requires a static IP configuration, use the command linux updates=http://[any] ip=[IP address] netmask=[netmask] dns=[dns].

When installing Red Hat Enterprise Linux 5.3 on a fully virtualized guest, do not use the kernel-xen kernel. Using this kernel on fully virtualized guests can cause your system to hang.

If you are using an Installation Number when installing Red Hat Enterprise Linux 5.3 on a fully virtualized guest, be sure to deselect the Virtualization package group during the installation. The Virtualization package group option installs the kernel-xen kernel.

Note that paravirtualized guests are not affected by this issue. Paravirtualized guests always use the kernel-xen kernel.

If you are using the Virtualized kernel when upgrading from Red Hat Enterprise Linux 5 to 5.2, you must reboot after completing the upgrade. You should then boot the system using the updated Virtualized kernel.

The hypervisors of Red Hat Enterprise Linux 5 and 5.2 are not ABI-compatible. If you do not boot the system after upgrading using the updated Virtualized kernel, the upgraded Virtualization RPMs will not match the running kernel.

When upgrading to Red Hat Enterprise Linux 5.1 or later from Red Hat Enterprise Linux 4.6, gcc4 may cause the upgrade to fail. As such, you should manually remove the gcc4 package before upgrading.

The firstboot language plugin has been removed, as it does not properly and completely reconfigure the system when a new language is selected.

The use of Challenge Handshake Authentication Protocol (CHAP) during installation is not supported. As such, CHAP should only be enabled after installation.

If your system boots through an iBFT device, configure CHAP in the iBFT BIOS/firmware setup screen. Your CHAP settings will then be used in the next boot.

If your system boots through PXE iSCSI, configure CHAP through iscsiadm. After configuring, use mkinitrd to ensure that your CHAP settings are used in the next boot.

When provisioning guests during installation, the RHN tools for guests option will not be available. When this occurs, the system will require an additional entitlement, separate from the entitlement used by dom0.

To prevent the consumption of additional entitlements for guests, install the rhn-virtualization-common package manually before attempting to register the system to Red Hat Network.

Installing Red Hat Enterprise Linux 5.3 on a system with multiple network interfaces and manually specified IPv6 addresses may result in a partially incorrect networking setup. When this occurs, your IPv6 settings will not be visible on the installed system.

To work around this, set NETWORKING_IPV6 to yes in /etc/sysconfig/network. Then, restart your network connection using the command service network restart.

If your system has yum-rhn-plugin-0.5.2-5.el5_1.2 (or an earlier version) installed, you will be unable to upgrade to Red Hat Enterprise Linux 5.3 through yum update. To work around this, upgrade your yum-rhn-plugin to the latest version (using yum update yum-rhn-plugin) before running yum update.

Previously, anaconda could not access more than 8 SmartArray controllers. In this update, this issue has been resolved.

A driver disk, supplied by an OEM, is a single image file (*.img), containing potentially multiple driver packages and kernel modules. These drivers are used during installation to support hardware that otherwise would not be recognized by Red Hat Enterprise Linux 5. Once the driver packages and kernel modules are installed on the system, they are placed in the initial RAM disk (initrd) so that they are loaded when the system boots.

With this release, installation can automatically detect a driver disk (based on its file system label), thereby using the content of that disk during installation. This behavior is controlled by the installation command line option dlabel=on, which enables the automatic search. dlabel=on is the default setting for this release.

All block devices with the file system label OEMDRV are examined and drivers are loaded from these devices in the order by which they are detected.

Existing encrypted block devices that contain vfat file systems will appear as type foreign in the partitioning interface; as such, these devices will not be mounted automatically during system boot. To ensure that such devices are mounted automatically, add an appropriate entry for them to /etc/fstab. For details on how to do so, refer to man fstab.

The minimum RAM required to install Red Hat Enterprise Linux 5.2 is 1GB; the recommended RAM is 2GB. If a machine has less than 1GB RAM, the installation process may hang.

Further, PowerPC-based machines that have only 1GB of RAM experience significant performance issues under certain RAM-intensive workloads. For a Red Hat Enterprise Linux 5.2 system to perform RAM-intensive processes optimally, 4GB of RAM is recommended. This ensures the system has the same number of physical pages as was available on PowerPC machines with 512MB of RAM running Red Hat Enterprise Linux 4.5 or earlier.

anaconda now supports both ports on CHPID for OSA Express3 cards. The installer will prompt for the port number in the initial stage of the installation. The value provided for the port also affects installed network interface startup script. When port 1 is selected, the value portno=1 is added to OPTIONS parameter of ifcfg-eth* file.

Installation on a machine with existing Linux or non-Linux filesystems on DASD block devices may cause the installer to halt. If this happens, it is necessary to clear out all existing partitions on the DASD devices you want to use and restart the installer.

If your system only has 512MB of RAM, attempting to install Red Hat Enterprise Linux 5.3 may fail. To prevent this, perform a base installation first and install all other packages after the installation finishes.

Using yum to install packages from the 32-bit Compatibility Layer disc may fail. If it does, it is because the Red Hat package signing key was not imported into the RPM database. This happens if you have not yet connected to Red Hat Network and obtained updates. To import the key manually, run the following command as root:

rpm --import /etc/pki/rpm-gpg/RPM-GPG-KEY-redhat-release

Once the Red Hat GPG key is imported, you may now use yum to install packages from the 32-bit Compatibility Layer disc.

Note that when installing from this disc, it is advisable to use yum instead of rpm to ensure that base OS dependencies are addressed during installation.

The Intel High Definition Audio driver in ALSA has been updated.

High-Definition Multimedia Interface (HDMI) audio support on AMD ATI integrated chipsets has been updated.

The following Wacom graphics tablets are now supported through the linuxwacom drivers:

the lpfc driver for Emulex Fibre Channel Host Bus Adapters has been updated to version 8.2.0.33.2p. This applies several upstream changes, most notably:

dm-multipath now has inbox support for IBM DS4000.

The ixgbe driver now supports the 82598AT dual-port adapter and the 82598 CX4 adapter.

the jsm driver has been updated to add support for Digi Neo PCI Express 4 HiProfile I/O adapters.

hp-ilo: driver added, providing support for HP Integrated Lights Out (iLO) technology.

The radeon_tp driver is now fully supported in this release. This driver enables the ATI R500/R600 chipsets.

This driver also features the following capabilities:

The powernow-k8 driver is now included in this release as a loadable module. This ensures that existing driver frameworks (such as the Red Hat Driver Update Model and Dell DKMS) can deliver powernow-k8 driver updates to users as RPM packages without requiring them to upgrade the kernel.

For this release, Red Hat is re-adding pnm2ppa in order to provide support for legacy printers. Note, however, that this support is deprecated and will be discontinued in future major releases.

The ccid driver has been re-based to add support for USB Smartcard keyboards.

the uvcvideo drivers for USB video devices has been added to the kernel in Red Hat Enterprise Linux 5.3.

The bnx2 driver for the Broadcom NetXtreme II network cards has been updated to version 1.7.9. This update fixes the ethernet ring buffer options on controllers that use bnx2 to fix a bug that caused the system to panic at boot.

The e1000e driver for Intel PRO/1000 ethernet devices has been updated to the upstream version 0.3.3.3-k2. With this update, the EEPROM and NVM of supported devices are now write-protected.

igb: driver for Intel Gigabit Ethernet Adapters has been updated to version 1.2.45-k2, adding support for 82576 based devices.

the ixgbe driver for Intel(R) 10 Gigabit PCI Express network devices has been updated to version 1.3.18-k4.

the niu driver has been added to Red Hat Enterprise Linux 5.3, adding support for 10Gbps ethernet devices on Sun CP3220 systems.

the ipw2100 and ipw2200 drivers for Intel PRO Wireless devices has been backported to Red Hat Enterprise Linux 5.3 from Linux Kernel 2.6.25.

the bcm43xx driver for Broadcom Wireless devices has been backported to Red Hat Enterprise Linux 5.3 from Linux Kernel 2.6.25.

the ieee80211 support component for wireless devices has been backported to Red Hat Enterprise Linux 5.3 from Linux Kernel 2.6.25.

the zd1211rw driver for ZyDas Wireless devices has been updated to match the last non-mac80211 version from just prior to Linux 2.6.25.

the iwlwifi drivers have been updated to version from 2.6.26, adding 802.11n support to iwl4965 wireless devices. Several bug fixes included in post-2.6.26 versions of the driver were also incorporated into the backported driver.

the myri10ge driver for Myricom Myri-10G Ethernet devices has been updated to version 1.3.2-1.269.

the netxen driver for NetXen network cards has been updated to version 3.4.18.

The bnx2x driver for Broadcom Everest network devices has been updated to version 1.45.23, adding support for the 57711 hardware.

the forcedeth-msi driver has been updated to fix a bug that prevented proper link-up detection.

the ath5k driver for Atheros wireless devices has been backported to Red Hat Enterprise Linux 5.3 from Linux Kernel 2.6.26.

the rt2x00 drivers for Ralink wireless devices has been backported to Red Hat Enterprise Linux 5.3 from Linux Kernel 2.6.26.

the rtl8180 and rtl8187 drivers for Realtek wireless devices has been backported to Red Hat Enterprise Linux 5.3 from Linux Kernel 2.6.26.

cxgb3: driver (along with corresponding firmware) is now included with this release. This driver supports the Chelsio RDMA 10Gb PCI-E Ethernet adapter.

3w-xxxx: driver for 3ware SATA RAID Controllers updated to version 1.26.03. This applies several upstream changes, most notably:

3w-9xxx: driver for 3ware SATA RAID Controllers updated to version 2.26.08. This applies several upstream changes, most notably:

megaraid_sas: driver updated to version 4.01-rh1. Several bug fixes are applied by this update, including:

the SCSI device handler infrastructure (scsi_dh) has been updated, providing the following improvements:

the qla2xxx driver for QLogic Fibre Channel Host Bus Adapters has been updated, adding support for ISP84XX type cards.

the ibmvscsi drivers for emulating virtual SCSI (vSCSI) devices has been updated, providing support for virtualized tape devices.

lpfc: driver updated to version 8.2.0.30. This update applies several bug fixes and enhancements, including:

the cciss driver for HP Smart Array controllers has been updated to version 3.6.20-RH2.

relayfs previously had a buffer size limit of 64MB. In this update, the limitation of the memory allocated to relayfs for on-memory buffers has been increased to 4095MB. This allows SystemTap and other tracing tools that utilize relayfs the ability to trace more events.

The driver for Dell Remote Access Controller 4 (DRAC4) was not present. Consequently, any virtual devices provided by the DRAC4 were not being detected by the kernel. In this update, the pata_sil680 kernel module that provides the appropriate driver has been added, which resolves this issue.

The message buffers for the relay interface were only allocated for online CPUs when relay_open() was called. Consequently, if an off-line CPU was turned on after relay_open() was called, a kernel panic would occur. In this update, a new message buffer is allocated dynamically if any new CPUs are added.

The driver for 8250 based serial ports has been updated to add support for DSR/DTR hardware flow control.

Support for Dell Wireless Wide Area Network (WWAN) cards has been added to the kernel. Devices that are now supported are:

the thinkpad_acpi kernel module has been updated to provide enhanced support for newer Thinkpad models.

The soft lockup detector can now be configured to trigger a kernel panic instead of a warning message. This makes it possible for users to generate and analyze a crash dump during a soft lockup for forensic purposes.

To configure the soft lockup detector to generate a panic, set the kernel parameter soft_lockup to 1. This parameter is set to 0 by default.

oprofile did not correctly identify processors based on the Next-Generation Intel Microarchitecture (Nehalem). Consequently, the performance monitoring unit could not be used and the processor fell back to the timer interrupt. The kernel has been updated to resolve this issue.

Support has been added to the kernel for the CPU power state, C3, on the Next-Generation Intel Microarchitecture (Nehalem). The ability to enter C3 (also known as the sleep state) improves the power efficiency of the CPU when idle.

Previously, the MAX_ARG_PAGES limit that is set in the kernel was too low, and may have resulted in the following error:

execve: Argument list too long

autofs4 updates have been backported to Red Hat Enterprise Linux 5.3 from linux kernel version 2.6.27.

Red Hat Enterprise Linux 5.3 now includes the ability to specify that core files be piped to a forked copy of a user space application, rather than directly to a file. This is enabled by placing | path/to/applicationin /proc/sys/kernel/core_pattern. When a core is dumped, a copy of the specified application will be executed, and the core will be piped to it on stdin. This allows for the core to be augmented, analyzed and actively handled at core dump time.

The file /proc/cpuinfo now reports the ID of the Advanced Programmable Interrupt Controller (APIC) that is used by each individual CPU.

The Machine Check Exception (MCE) kernel subsystem has been enhanced to support larger memory configurations as needed by new systems.

The mount command now supports Kerberos authentication when mounting filesystems via Samba. The sec=krb5 or sec=krb5i switch allows the kernel to call a userspace application (cifs.upcall) which returns a SPNEGO (Simple and Protected GSSAPI Negotiation Mechanism) security blob (Binary Large OBject). The kernel can then use this blob to authenticate with the server and mount the requested filesystem.

If you configured the kernel parameter kernel.unknown_nmi_panic on a system that used the IOAPIC NMI watchdog method, a kernel panic could occur. This is because the NMI watchdog could not disable the source of NMIs securely.

With this release, the NMI watchdog code has been revised to allow users to safely disable the NMI source. As such, you can now safely configure the kernel parameter kernel.unknown_nmi_panic on systems that use the IOAPIC NMI watchdog method.

The powernowk8 driver was not performing sufficient checks on the number of running CPUs. Consequently, when the driver was started, a kernel oops error message may have been reported. In this update the powernowk8 driver verifies that the number of supported CPUs (supported_cpus) equals the number of online CPUs (num_online_cpus), which resolves this issue.

CPUFreq, the kernel subsystem that scales CPU frequency and voltage, has been updated with improved support for Cell Processors. This update implements a Synergistic Processing Unit (SPU) aware CPUFreq governor that enhances the power management of Cell processors.

Error Detection and Correction (EDAC) is now supported on the Cell Broadband Engine Architecture in Red Hat Enterprise Linux 5.3. To enable EDAC, use the command: modprobe cell_edac

To check this module has been added to your running kernel, check /var/log/dmesg for output like the following:

EDAC MC: Ver: 2.0.1 Oct  4 2008
EDAC MC0: Giving out device to cell_edac MIC: DEV cbe-mic
EDAC MC1: Giving out device to cell_edac MIC: DEV cbe-mic

If correctable memory errors are encountered, the following message will be returned to the console:

EDAC MC0: CE page 0xeff, offset 0x5700, grain 0, syndrome 0x51, row 0, channel
0, label "":

Debugging with hardware watchpoints using a variable that is shared between multiple threads was causing the GNU Debugger (GDB) to erratically miss trigger events. The kernel has been updated to allow GDB to consistently receive the watchpoint triggers, improving the reliability of the debugging session.

kprobe-booster is now supported on the ia64 and x86_64 architectures, allowing users to probe kernel events much faster. This feature will also decrease the overhead caused by probing tools (e.g. SystemTap and Kprobes) on servers running on 64-bit architecture.

Support has been added to the kernel for the _PTC (Processor Throttling Control), _TSS (Throttling Supported States) and _TPC (Throttling Present Capabilities) objects. This support, which is part of the Advance Configuration and Power Interface specification (ACPI) provides improved management of processor throttling.

In zipl.conf, parameters enclosed with double quotes inside of single quotes (ie parameters='vmhalt="LOGOFF"') were being parsed incorrectly. Consequently, installing the kernel-kdump package may have failed, resulting in the error:

grubby fatal error: unable to find a suitable template

The Dual-Core Intel Itanium 2 processor filled out machine check architecture (MCA) records differently to previous Intel Itanium processors. The cache check and bus check target identifiers can now be different in some circumstances. The kernel has been updated to find the correct target identifier.

kprobe-booster is now supported on the ia64 and x86_64 architectures, allowing users to probe kernel events much faster. This feature will also decrease the overhead caused by probing tools (e.g. SystemTap and Kprobes) on servers running on 64-bit architecture.

In this update, support for pselect() and ppoll() system calls has been added to the kernel.

The blktap (blocktap) userspace toolkit has been updated, providing the functionality to monitor the transfer statistics of blktap backed virtualized guests.

Support was added for the Intel Extended Page Table (EPT) feature, improving performance of fully virtualized guests on hardware that supports EPT.

e1000 network device emulation for guests has been added in this update, supporting only Windows 2003 guests on the ia64 architecture. To use e1000 emulation, the xm command must be used.

Drivers for virtio, the platform for I/O virtualization in KVM, has been backported to Red Hat Enterprise Linux 5.3 from Linux Kernel 2.6.27. These drivers will enable KVM guests to achieve higher levels of I/O performance. Various userspace components such as: anaconda, kudzu, lvm, selinux and mkinitrd have also been updated to support virtio devices.

The native Linux kernel supports vmcoreinfo automatically, but, to setup kdump on dom0 domains, the kernel-xen-debuginfo package was needed. With this release, the kernel and the hypervisor have been modified and now support vmcoreinfo reading and writing kdump natively. Users needing to use kdump for de-bugging or other investigations on dom0 domains can now do so without installing the debuginfo or debuginfo-common packages.

Fully virtualized Red Hat Enterprise Linux 5 guests encountered suboptimal performance when using emulated disk and network devices. In this update, the kmod-xenpv package has been included to simplify the use of paravirtualized disks and networks in fully virtualized guests.

Using these drivers in fully virtualized guests can significantly improve the performance and functionality of fully virtualized guests. Bug fixes made for netfront and block front drivers are immediately realized and synchronized with the kernel package.

Guests now have the ability to utilize 2MB backing page memory tables, which can improve system performance.

The data for TTY device activity reports was not generating correctly. Consequently, the command sar -y failed, returning the error:

Requested activities not available in file

In this updated package, sar has been corrected so the -y option outputs the TTY device activity.

Previously, setting max_fds to unlimited in /etc/multipath.conf would prevent the multipathd daemon from starting. If number of open file descriptors needs to be set to the system maximum, max_fds should be set to max.

mod_perl is now re-based to version 2.0.4, the latest upstream release. This update applies several updates, which include a bug fix that now allows mod_perl to work properly with Bugzilla 3.0.

cups is now re-based to version 1.3.7. This update applies several bug fixes and enhancements, including:

lm_sensors has been re-based to version 2.10.7. This update applies several upstream enhancements and bug fixes, including a fix that prevents libsensors from crashing with a General parse error message when k8temp is also loaded.

elfutils has been updated in this release to address the following bugs:

vnc-server is now re-based to version 4.1.2-14.el5. This update applies the following fixes:

smartmontools has been re-based to version 5.38. This update improves autodetection of hardware devices, improves support for CCISS RAID arrays, and features a larger database of supported devices.

This update also fixes a bug wherein SELinux prevented smartmontools from monitoring 3ware RAID devices. smartmontools can now monitor such devices properly.

python-urlgrabber has been re-based to version 3.1.0-5. This applies several bug fixes from upstream, including:

yum-utils is now re-based to upstream version 1.1.16. This applies several bug fixes, including:

This update also includes the yum-fastestmirror plugin, which enables yum to choose the fastest repository in a mirrorlist.

Samba has been re-based to upstream version 3.2.0. This fixes several bugs, including one that prevented users from joining domains that used Windows 2003 as their name server. This update also fixes a bug that caused samba domain membership to break after changing the system password using net rpc changetrustpw.

For a more comprehensive list of upstream samba updates included this release, refer to http://www.samba.org/samba/history/samba-3.0.32.html

OpenLDAP has been re-based to upstream version 2.3.43. This applies several upstream bug fixes, including:

Red Hat now distributes additional overlays for OpenLDAP server. Except for syncprov, all overlays can be found in separate openldap-servers-overlays packages, compiled as dynamically loadable modules. The syncprov overlay is statically linked to the OpenLDAP server to maintain compatibility with older OpenLDAP releases.

Because the xterm binary had the set group ID (setgid) bit configured, certain environmental variables (such as LD_LIBRARY_PATH and TMPDIR) were unset. In this release, the xterm binary now has mode 0755 permissions configured, which resolves this issue.

The recommended method for balancing the load on NIS servers when multiple machines are connecting with ypbind has changed with this release. The ypbind daemon's behavior has not changed: it still pings all NIS servers listed in the /etc/ypbind configuration file and then binds to the single fastest-responding server. Before, it was recommended to list all available NIS servers in each machine's /etc/ypbind.conf configuration file. However, because even servers under high load can respond quickly to this ping, thus inadvertently increasing their own load, it is now recommended for administrators to list a smaller number of available NIS servers in each machine's ypbind.conf, and to vary this list across machines. In this way, NIS servers are automatically load-balanced due to not every NIS server being listed as being available to every machine.

OpenMotif has been re-based to upstream version 2.3.1. This update applies several bug fixes, including:

dbus has been re-based to version 1.1.2. This update fixes a bug wherein multi-threaded programs could cause a deadlock in dbus. In previous releases, as one thread listened to dbus and processed messages, the second thread would send messages to dbus.

strace has been re-based to version 4.5.18. This fixes several bugs, including:

cpuspeed has been updated to version 1.2.1-5. With this update, the cpuspeed init script now loads the speedstep-centrino module if all other module loads fail. In addition, a user-space bug that prevented the Powernow-k8 module from loading is now fixed.

The frysk suite of tools have been removed completely from this distribution. frysk was originally introduced as a technology preview in Red Hat Enterprise Linux 5.0.

Previously, the partition I/O statistics provided by the iostat -x command were incomplete. In this update, partition statistics are now calculated in the same manner as disk statistics, providing coherent and comprehensive I/O statistics at the partition level.

A password disclosure flaw was found with configuration file for the Dovecot mail server. If a system had the ssl_key_password option defined, any local user could view the SSL key password. (CVE-2008-4870)

To better protect even this value, however, the dovecot.conf file now supports the "!include_try" directive. The ssl_key_password option should be moved from dovecot.conf to a new file owned by, and only readable and writable by, root (ie 0600). This file should be referenced from dovecot.conf by setting the !include_try /path/to/password/file option.

ksh has been re-based to version 2008-02-02. This update adds multi-byte character handling, addresses many job control problems and applies several bug fixes from upstream. Note that this update to ksh preserves compatibility for existing scripts.

A vmconvert bug prevented it from working properly on the vmur device node (/dev/0.0.000c). This caused vmconvert to fail when attempting to access dumps on the vmur device with the error vmconvert: Open dump file failed! (Permission denied). An update to s390utils in this release fixes this issue.

The init script and config file for the mon_procd daemon and mon_fsstatd daemon were missing from the s390utils package. Consequently these daemons could not be built and used. The missing files have been added in this update which resolves this issue.

A bug that prevented the ehci_hcd module from reloading on this architecture is now fixed. This ensures that the Belkin 4-port PCI-Express USB Lily adapter (and other similar devices) now function properly with Red Hat Enterprise Linux 5 when they use the ehci_hcd module.

The libhugetlbfs library is now re-based to version 1.3. This update applies several upstream improvements to the library, thereby improving the performance of applications that use Huge pages.

For a complete list of updates to libhugetlbfs, refer to the following link:

http://sourceforge.net/mailarchive/message.php?msg_name=20080515170754.GA1830%40us.ibm.com

In Red Hat Enterprise Linux 5.2, a 64-bit version of httpd was included in this architecture in addition to the existing 32-bit httpd. If a user installed both versions, an httpd conflict would occur, preventing httpd from functioning properly.

To resolve this issue, the 64-bit version of httpd has been removed from this release. Upgrading httpd for this release will automatically remove the 64-bit version of httpd as well.

When using the new disk encryption feature to encrypt the root filesystem, the following error message will be reported on the console when shutting down the system:

Stopping disk encryption [FAILED]

This message can safely be ignored, the shutdown process will complete successfully.

When using an encrypted device, the following error message may be reported during bootup:

insmod: error inserting '/lib/aes_generic.ko': -1 File exists

Installation using a Multiple Device (MD) RAID on top of multipath will result in a machine that cannot boot. Multipath to Storage Area Network (SAN) devices which provide RAID internally are not affected.

When a large number of LUNs are added to a node, multipath can significantly increase the time it takes for udev to create device nodes for them. If you experience this problem, you can correct it by deleting the following line in /etc/udev/rules.d/40-multipath.rules:

KERNEL!="dm-[0-9]*", ACTION=="add", PROGRAM=="/bin/bash -c '/sbin/lsmod | /bin/grep ^dm_multipath'", RUN+="/sbin/multipath -v0 %M:%m"

When upgrading from an earlier version of Red Hat Enterprise Linux to 5.3, you may encounter the following error:

Updating  : mypackage                 ################### [ 472/1655]
rpmdb: unable to lock mutex: Invalid argument

The cause of the locking issue is that the shared futex locking in glibc was enhanced with per-process futexes between 5.2 and 5.3. As a result, programs running against the 5.2 glibc can not properly perform shared futex locking against programs running with the 5.3 glibc.

This particular error message is a side effect of a package calling rpm as part of its install scripts. The rpm instance performing the upgrade is using the prior glibc throughout the upgrade, but the rpm instance launched from within the script is using the new glibc.

To avoid this error, upgrade glibc first in a separate run:

# yum update glibc
# yum update

mvapich and mvapich2 in Red Hat Enterprise Linux 5 are compiled to support only InfiniBand/iWARP interconnects. Consequently, they will not run over ethernet or other network interconnects.

On systems with more than two encrypted block devices, anaconda has a option to provide a global passphrase. The init scripts, however, do not support this feature. When booting the system, entering each individual passphrase for all encrypted devices will be required.

When upgrading openmpi using yum, the following warning may be returned:

cannot open `/tmp/openmpi-upgrade-version.*' for reading: No such file or directory

Configuring IRQ SMP affinity has no effect on some devices that use message signalled interrupts (MSI) with no MSI per-vector masking capability. Examples of such devices include Broadcom NetXtreme Ethernet devices that use the bnx2 driver.

If you need to configure IRQ affinity for such a device, disable MSI by creating a file in /etc/modprobe.d/ containing the following line:

options bnx2 disable_msi=1

Alternatively, you can disable MSI completely using the kernel boot parameter pci=nomsi.

The CD-ROM/DVD-ROM unit on Dell PowerEdge R905 servers does not work with Red Hat Enterprise Linux 5. Please see Knowledgebase #13121 for more details: http://kbase.redhat.com/faq/FAQ_103_13121.

A bug in the updated /etc/udev/rules.d/50-udev.rules file prevents the creation of persistent names for tape devices with numbers higher than 9 in their names. For example, a persistent name will not be created for a tape device with a name of nst12.

To work around this, add an asterisk (*) after each occurrence of the string nst[0-9] in /etc/udev/rules.d/50-udev.rules.

The smartctl tool cannot properly read SMART parameters from SATA devices.

A bug in previous versions of openmpi and lam may prevent you from upgrading these packages. This bug manifests in the following error (when attempting to upgrade openmpi or lam:

error: %preun(openmpi-[version]) scriptlet failed, exit status 2

As such, you need to manually remove older versions of openmpi and lam in order to install their latest versions. To do so, use the following rpm command:

rpm -qa | grep '^openmpi-\|^lam-' | xargs rpm -e --noscripts --allmatches

When using dm-multipath, if features "1 queue_if_no_path" is specified in /etc/multipath.conf then any process that issues I/O will hang until one or more paths are restored.

To avoid this, set no_path_retry [N] in /etc/multipath.conf (where [N] is the number of times the system should retry a path). When you do, remove the features "1 queue_if_no_path" option from /etc/multipath.conf as well.

If you need to use "1 queue_if_no_path" and experience the issue noted here, use dmsetup to edit the policy at runtime for a particular LUN (i.e. for which all the paths are unavailable).

To illustrate: run dmsetup message [device] 0 "fail_if_no_path", where [device] is the multipath device name (e.g. mpath2; do not specify the path) for which you want to change the policy from "queue_if_no_path" to "fail_if_no_path".

Enabling multiple installed versions of the same kernel module is not supported. In addition to this, a bug in the way kernel module versions are parsed can sometimes result in enabling an older version of the same kernel module.

Red Hat recommends that when you install a newer version of an installed kernel module, you should delete the older one first.

Executing kdump on an IBM Bladecenter QS21 or QS22 configured with NFS root will fail. To avoid this, specify an NFS dump target in /etc/kdump.conf.

IBM T60 laptops will power off completely when suspended and plugged into a docking station. To avoid this, boot the system with the argument acpi_sleep=s3_bios.

The QLogic iSCSI Expansion Card for the IBM Bladecenter provides both ethernet and iSCSI functions. Some parts on the card are shared by both functions. However, the current qla3xxx and qla4xxx drivers support ethernet and iSCSI functions individually. Both drivers do not support the use of ethernet and iSCSI functions simultaneously.

Because of this limitation, successive resets (via consecutive ifdown/ifup commands) may hang the device. To avoid this, allow a 10-second interval after an ifup before issuing an ifdown. Also, allow the same 10-second interval after an ifdown before issuing an ifup. This interval allows ample time to stabilize and re-initialize all functions when an ifup is issued.

Laptops equipped with the Cisco Aironet MPI-350 wireless may hang trying to get a DHCP address during any network-based installation using the wired ethernet port.

To work around this, use local media for your installation. Alternatively, you can disable the wireless card in the laptop BIOS prior to installation (you can re-enable the wireless card after completing the installation).

Boot-time logging to /var/log/boot.log is not available in Red Hat Enterprise Linux 5.3.

The system may not successfully reboot into a kexec/kdump kernel if X is running and using a driver other than vesa. This problem only exists with ATI Rage XL graphics chipsets.

If X is running on a system equipped with ATI Rage XL, ensure that it is using the vesa driver in order to successfully reboot into a kexec/kdump kernel.

When using Red Hat Enterprise Linux 5.2 on a machine with an nVidia CK804 chipset installed, the following kernel messages may appear:

kernel: assign_interrupt_mode Found MSI capability
kernel: pcie_portdrv_probe->Dev[005d:10de] has invalid IRQ. Check vendor BIOS

These messages indicate that certain PCI-E ports are not requesting IRQs. They do not, however, affect the operation of the machine in any way.

Removable storage devices (such as CDs and DVDs) do not automatically mount when you are logged in as root. As such, you will need to manually mount the device through the graphical file manager.

Alternatively, you can run the following command to mount a device to /media:

mount /dev/[device name] /media

When a LUN is deleted on a configured storage system, the change is not reflected on the host. In such cases, lvm commands will hang indefinitely when dm-multipath is used, as the LUN has now become stale.

To work around this, delete all device and mpath link entries in /etc/lvm/.cache specific to the stale LUN.

To find out what these entries are, run the following command:

ls -l /dev/mpath | grep [stale LUN]

For example, if [stale LUN] is 3600d0230003414f30000203a7bc41a00, the following results may appear:

lrwxrwxrwx 1 root root 7 Aug  2 10:33 /3600d0230003414f30000203a7bc41a00 -> ../dm-4
lrwxrwxrwx 1 root root 7 Aug  2 10:33 /3600d0230003414f30000203a7bc41a00p1 -> ../dm-5

This means that 3600d0230003414f30000203a7bc41a00 is mapped to two mpath links: dm-4 and dm-5.

As such, the following lines should be deleted from /etc/lvm/.cache:

/dev/dm-4 
/dev/dm-5 
/dev/mapper/3600d0230003414f30000203a7bc41a00
/dev/mapper/3600d0230003414f30000203a7bc41a00p1
/dev/mpath/3600d0230003414f30000203a7bc41a00
/dev/mpath/3600d0230003414f30000203a7bc41a00p1

Running the multipath command with the -ll option can cause the command to hang if one of the paths is on a blocking device. Note that the driver does not fail a request after some time if the device does not respond.

This is caused by the cleanup code, which waits until the path checker request either completes or fails. To display the current multipath state without hanging the command, use multipath -l instead.

Upgrading pm-utils from a Red Hat Enterprise Linux 5.2 Beta version of pm-utils will fail, resulting in the following error:

error: unpacking of archive failed on file /etc/pm/sleep.d: cpio: rename

To prevent this from occurring, delete the /etc/pm/sleep.d/ directory prior to upgrading. If /etc/pm/sleep.d contains any files, move those files to /etc/pm/hooks/.

Hardware testing for the Mellanox MT25204 has revealed that an internal error occurs under certain high-load conditions. When the ib_mthca driver reports a catastrophic error on this hardware, it is usually related to an insufficient completion queue depth relative to the number of outstanding work requests generated by the user application.

Although the driver will reset the hardware and recover from such an event, all existing connections at the time of the error will be lost. This generally results in a segmentation fault in the user application. Further, if opensm is running at the time the error occurs, then you need to manually restart it in order to resume proper operation.

When installing Red Hat Enterprise Linux 5 on a guest, the guest is configured to explicitly use a temporary installation kernel provided by dom0. Once installation finishes, it can then use its own bootloader. However, this can only be achieved by forcing the guest's first reboot to be a shutdown.

As such, when the Reboot button appears at the end of the guest installation, clicking it shuts down the guest, but does not reboot it. This is an expected behavior.

Note that when you boot the guest after this it will then use its own bootloader.

Running rpmbuild on the compiz source RPM will fail if any KDE or qt development packages (for example, qt-devel) are installed. This is caused by a bug in the compiz configuration script.

To work around this, remove any KDE or qt development packages before attempting to build the compiz package from its source RPM.

If your system has either ATI Radeon R500 or R600 graphics card equipped, firstboot will not run after installation. The system will go directly to the graphical login screen and skip firstboot altogether. If you attempt to run firstboot manually (i.e. from a failsafe terminal), the X session will crash.

This issue is caused by the driver used by the ATI Radeon R500/R600 hardware. The default driver used by these graphics cards are still in technology preview. To work around this, backup your /etc/X11/xorg.conf file; then, configure X to use the supported vesa driver instead using the following command:

system-config-display --reconfig --set-driver=vesa

You can now run firstboot. To switch back to your old settings, restore your original /etc/X11/xorg.conf.

If your system uses the TSC timer, the gettimeofday system call may move backwards. This is because of an overflow issue that causes the TSC timer to jump forward significantly in some cases; when this occurs, the TSC timer will correct itself, but will ultimately register a movement backwards in time.

This issue is particularly critical for time-sensitive systems, such as those used for transaction systems and databases. As such, if your system needs precision timing, Red Hat strongly recommends that you set the kernel to use another timer (for example, HPET).

Attempting to run sniff may result in an error. This is because some required packages are not installed with dogtail.

To prevent this from occurring, install the following packages manually:

Thin Provisioning (also known as "virtual provisioning") will be first released with EMC Symmetrix DMX3 and DMX4. Please refer to the EMC Support Matrix and Symmetrix Enginuity code release notes for further details.

In /etc/multipath.conf, setting max_fds to unlimited will prevent the multipathd daemon from starting up properly. As such, you should use a sufficiently high value instead for this setting.

SystemTap currently uses GCC to probe user-space events. GCC is, however, unable to provide debuggers with precise location list information for parameters. In some cases, GCC also fails to provide visibility on some parameters. As a consequence, SystemTap scripts that probe user-space may return inaccurate readings.

The IBM T41 laptop model does not enter Suspend Mode properly; as such, Suspend Mode will still consume battery life as normal. This is because Red Hat Enterprise Linux 5 does not yet include the radeonfb module.

To work around this, add a script named hal-system-power-suspend to /usr/share/hal/scripts/ containing the following lines:

chvt 1
radeontool light off
radeontool dac off

This script will ensure that the IBM T41 laptop enters Suspend Mode properly. To ensure that the system resumes normal operations properly, add the script restore-after-standby to the same directory as well, containing the following lines:

radeontool dac on
radeontool light on
chvt 7

If the edac module is loaded, BIOS memory reporting will not work. This is because the edac module clears the register that the BIOS uses for reporting memory errors.

The current Red Hat Enterprise Linux Driver Update Model instructs the kernel to load all available modules (including the edac module) by default. If you wish to ensure BIOS memory reporting on your system, you need to manually blacklist the edac modules. To do so, add the following lines to /etc/modprobe.conf:

blacklist edac_mc
blacklist i5000_edac
blacklist i3000_edac
blacklist e752x_edac

Red Hat Enterprise Linux 5.3 can detect online growing or shrinking of an underlying block device. However, there is no method to automatically detect that a device has changed size, so manual steps are required to recognize this and resize any file systems which reside on the given device(s). When a resized block device is detected, a message like the following will appear in the system logs:

VFS: busy inodes on changed media or resized disk sdi

If the block device was grown, then this message can be safely ignored. However, if the block device was shrunk without shrinking any data set on the block device first, the data residing on the device may be corrupted.

It is only possible to do an online resize of a filesystem that was created on the entire LUN (or block device). If there is a partition table on the block device, then the file system will have to be unmounted to update the partition table.

If your system has a GFS2 file system mounted, a node may hang if a cached inode is accessed in one node and unlinked on a different node. When this occurs, the hung node will be unavailable until you fence and recover it via the normal cluster recovery mechanism. The function calls gfs2_dinode_dealloc and shrink_dcache_memory will also appear in the stack traces of any processes stuck in the hung node.

This issue does not affect single-node GFS2 file systems.

The following message may be encountered during system boot:

Could not detect stabilization, waiting 10 seconds.
Reading all physical volumes.  This may take a while...

The current implementation of User Payload Access in ipmitool allows you to configure devices, but does not allow you to retrieve the current settings for those devices.

Using the swap --grow parameter in a kickstart file without setting the --maxsize parameter at the same time makes anaconda impose a restriction on the maximum size of the swap partition. It does not allow it to grow to fill the device.

For systems with less than 2GB of physical memory, the imposed limit is twice the amount of physical memory. For systems with more than 2GB, the imposed limit is the size of physical memory plus 2GB.

The gfs2_convert program may not free up all blocks from the GFS metadata that are no longer used under GFS2. These unused metadata blocks will be discovered and freed the next time gfs2_fsck is run on the file system. It is recommended that gfs2_fsck be run after the filesystem has been converted to free the unused blocks. These unused blocks will be flagged by gfs2_fsck with messages such as:

Ondisk and fsck bitmaps differ at block 137 (0x89) 
Ondisk status is 1 (Data) but FSCK thinks it should be 0 (Free)
Metadata type is 0 (free)

When running the bare-metal (non-Virtualized) kernel, the X server may not be able to retrieve EDID information from the monitor. When this occurs, the graphics driver will be unable to display resolutions highers than 800x600.

To work around this, add the following line to the ServerLayout section of /etc/X11/xorg.conf:

Option "Int10Backend" "x86emu"

Recording needs to be manually enabled on Dell M4300 and M6300. To do this, perform the following steps:

If encryption is enabled on the boot device during system installation, the following message will be logged during system boot:

padlock: VIA PadLock not detected.

Some machines that use NVIDIA graphics cards may display corrupted graphics or fonts when using the graphical installer or during a graphical login. To work around this, switch to a virtual console and back to the original X host.

On an IBM T61 laptop, Red Hat recommends that you refrain from clicking the glxgears window (when glxgears is run). Doing so can lock the system.

To prevent this from occurring, disable the tiling feature. To do so, add the following line in the Device section of /etc/X11/xorg.conf:

Option "Tiling" "0"

Recording needs to be manually enabled on Dell M4300 and M6300. To do this, perform the following steps:

If your system uses an Intel 945GM graphics card, do not use the i810 driver. You should use the default intel driver instead.

On dual-GPU laptops, if one of the graphics chips is Intel-based, the Intel graphics mode cannot drive any external digital connections (including HDMI, DVI, and DisplayPort). This is a hardware limitation of the Intel GPU. If you require external digital connections, configure the system to use the discrete graphics chip (in the BIOS).

When using Alt-SysRq-W to debug, the following warning message will appear:

Badness in smp_call_function at arch/powerpc/kernel/smp.c:223

Afterwards, the system will also warn that it will hang. This message should be ignored as it will not cause the system to hang.

Recording needs to be manually enabled on Dell M4300 and M6300. To do this, perform the following steps:

The size of the PPC kernel image is too large for OpenFirmware to support. Consequently, network booting will fail, resulting in the following error message:

Please wait, loading kernel...
/pci@8000000f8000000/ide@4,1/disk@0:2,vmlinux-anaconda: No such file or directory
boot: 

When running Red Hat Enterprise Linux 5.2 on a z/VM that has more than 2GB of guest storage defined, invalid data can be read from and written to any FCP and OSA device attached in QDIO mode with the Queued-I/O assist (QIOASSIST) option enabled. If your system has any such devices attached, Red Hat recommends that you download and install the corresponding z/VM Program Temporary Fix (PTF) from the following link:

http://www-1.ibm.com/support/docview.wss?uid=isg1VM64306

It is not possible to directly read and convert a z/VM dump into a file. Instead, you should first copy the dump from the z/VM reader into a Linux file system using vmur and convert the dump into a Linux-readable file using vmconvert.

The IBM System z does not provide a traditional Unix-style physical console. As such, Red Hat Enterprise Linux 5.2 for the IBM System z does not support the firstboot functionality during initial program load.

To properly initialize setup for Red Hat Enterprise Linux 5.2 on the IBM System z, run the following commands after installation:

Some Itanium systems cannot properly produce console output from the kexec purgatory code. This code contains instructions for backing up the first 640k of memory after a crash.

While purgatory console output can be useful in diagnosing problems, it is not needed for kdump to properly function. As such, if your Itanium system resets during a kdump operation, disable console output in purgatory by adding --noio to the KEXEC_ARGS variable in /etc/sysconfig/kdump.

Running perftest will fail if different CPU speeds are detected. As such, you should disable CPU speed scaling before running perftest.

When the kdump kernel is booted, the following error will appear in the boot log:

mknod: /tmp/initrd.[numbers]/dev/efirtc: No such file or directory

This error results from a malformed request to create the efirtc in an incorrect path. However, the device path in question is also created statically in the initramfs when the kdump service is started. As such, the run-time creation of the device node is redundant, harmless, and should not affect the performance of kdump.

Some systems may be unable to boot the kdump kernel properly. In such cases, use the machvec=dig kernel parameter.

Recording needs to be manually enabled on Dell M4300 and M6300. To do this, perform the following steps:

On Intel Itanium-based systems running SELinux in enforcing mode, either the allow_unconfined_execmem_dyntrans or allow_execmem Booleans must be turned on to allow the IA-32 Execution Layer (the ia32el service) to operate correctly. If the allow_unconfined_execmem_dyntrans Boolean is off, but the allow_execmem Boolean is on, which it is by default in Red Hat Enterprise Linux 5, the ia32el service supports 32-bit emulation; however, if both Booleans are off, emulation fails.