The following topics are covered in this document:
Changes to the Red Hat Enterprise Linux installation program (Anaconda)
Changes to drivers and hardware support
Changes to packages
The following section includes information specific to installation of Red Hat Enterprise Linux and the Anaconda installation program.
In order to upgrade an already-installed Red Hat Enterprise Linux 4 system to Update 1, you must use Red Hat Network to update those packages that have changed.
You may use Anaconda to perform a fresh installation of Red Hat Enterprise Linux 4 Update 1 or to perform an upgrade from the latest updated version of Red Hat Enterprise Linux 3 to Red Hat Enterprise Linux 4.
If you are copying the contents of the Red Hat Enterprise Linux 4 Update 1 CD-ROMs (in preparation for a network-based installation, for example) be sure you copy the CD-ROMs for the operating system only. Do not copy the Extras 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.
This section contains general information not specific to any other section of this document.
The openssh-3.9p1 package included in Red Hat Enterprise Linux 4 introduced two different modes of X11 forwarding: trusted and untrusted. In the default Red Hat Enterprise Linux 4 configuration, passing the -X flag to /usr/bin/ssh (or using the "ForwardX11 on" configuration option) enables untrusted X11 forwarding. This mode restricts the X11 protocol to prevent a malicious application using a forwarded SSH connection from compromising the security of the local X11 server (for example, by performing keystroke monitoring); but few X11 applications are usable in this mode.
In Red Hat Enterprise Linux 4 Update 1, the default configuration of the openssh client has been changed such that passing the -X flag enables trusted X11 forwarding. The trusted forwarding mode allows all X applications to work correctly when forwarded over an SSH connection; but, as with previous releases of Red Hat Enterprise Linux, it should only be used when invoking trusted applications.
X11 forwarding is disabled by default in Red Hat Enterprise Linux 4, which differs from previous Red Hat Enterprise Linux releases such that attempting to run a malicious X11 application over an ssh connection cannot compromise the local X11 server. You should only use X11 forwarding when connecting to trusted servers.
Red Hat Enterprise Linux 4 Update 1 now includes the diskdump facility,which can serve as an alternative to (or be used in conjunction with) the Red Hat netdump facility.
The diskdump facility for i386 systems currently support the aic7xxx, aic79xx, mpt fusion, megaraid, ata_piix, and sata_promise devices. On ia64 systems, the aic7xxx, aic79xx, mpt fusion, and sata_promise devices are supported. On AMD64 and Intel® EM64T systems, the aic7xxx, aic79xx, mpt fusion, megaraid, sata_promise, and ata_piix devices are supported. Finally, on PPC64 systems, the ipr and sym53c8xx_2 devices are supported.
The megaraid and SATA devices are newly supported in Red Hat Enterprise Linux 4 Update 1.
Usage of the diskdump facility requires a dedicated disk device or disk partitions that are large enough to contain all physical system memory. In the event of a system crash, memory will be written to the configured disk location. Upon subsequent reboot, the data will be copied from the configured disk location and formatted into a vmcore file, identical in functionality to that created by the netdump facility, and stored in the unique subdirectory /var/crash/. The vmcore file may be analyzed using the crash(8) utility.
The diskdump facility may fail to write a dump file if cluster mode is enabled on megaraid adapters. You can disable cluster mode on megaraid adapters using the device's WebBIOS utility. Consult your manufacturer documentation for more information on using WebBIOS.
The kernel modules required for the diskdump facility are automatically included in the Red Hat Enterprise Linux 4 kernel. The associated user-space diskdump package is named diskdumputils-1.0.1-5, and like netdump, is installed by default.
The appropriate disk location must first be configured and then preformatted for use. After formatting, the diskdump facility may be turned on with chkconfig(8), and then the service must be started. Detailed documentation concerning configuration and user tasks is included with the diskdumputils at the following:
Further information can be found in the diskdumpfmt(8), diskdumpctl(8), and savecore(8) man pages.
This section contains notes relating to the Red Hat Enterprise Linux 4 Update 1 kernel.
An issue that causes USB mice to stop responding after a few hours of use has been discovered on certain systems. A BIOS setting that enables USB emulation causes 2.6 kernel mouse driving to freeze, which necessitates either changing to a virtual console using Ctrl-Alt-Fx then switching back to the graphical desktop or unplugging and re-plugging the mouse in order to regain functionality.
To prevent the freezing of USB mice, it is recommended to disable USB Emulation support (also called USB Legacy Support) in the system's BIOS. Refer to your system manufacturer documentation for more information about finding and disabling this BIOS setting.
The Red Hat Enterprise Linux 4 Update 1 kernel automatically disables NUMA optimizations (numa=off) by default on systems using the AMD64 dual core processor. This ensures stable operation across multiple systems where each has a different system BIOS implementation for reporting dual core processors.
Users have the ability to safely override this default for a system where the manufacturer has stated conformance with the reporting of dual core processors as expected by Red Hat Enterprise Linux 4 Update 1 kernel.
Users can override the numa=off default by specifying numa=on on the Linux boot prompt or on the active kernel line in the grub.conf file. If the system fails to boot after enabling this function, remove the override and retry it. This limitation is expected to be removed in a future Red Hat Enterprise Linux 4 update.
This update includes bug fixes for a number of drivers. The more significant driver updates are listed below. In some cases, the original driver has been preserved under a different name, and is available as a non-default alternative for organizations that wish to migrate their driver configuration to the latest versions at a later time.
The migration to the latest drivers should be completed before the next Red Hat Enterprise Linux update is applied, because in most cases only one older-revision driver will be preserved for each update.
The following device drivers are updated in Red Hat Enterprise Linux 4 Update 1:
Emulex LightPulse Fibre Channel HBA (lpfc driver)
LSI Logic MegaRAID Controller family (megaraid_mbox driver)
Intel® PRO/Wireless 2100/2200 adapters (ieee80211/ipw2100/ipw2200 drivers)
Broadcom Tigon3 (tg3 driver)
Intel® Pro/100 Adapter family (e100 driver)
Intel® PRO/1000 Adapters (e1000 driver)
Serial ATA (SATA) devices (sata driver)
Neterion 10GB Ethernet adapter (s2io driver)
The kernel shipped with Red Hat Enterprise Linux 4 Update 1 includes the new megaraid_mbox driver from LSI Logic, which replaces the megaraid driver. The megaraid_mbox driver has an improved design, is compatible with the 2.6 kernel, and includes support for the latest hardware. However, megaraid_mbox does not support some of the older hardware that was supported by the megaraid driver.
Adapters with the following PCI vendor ID and device ID pairs are not supported by the megaraid_mbox driver:
vendor, device 0x101E, 0x9010 0x101E, 0x9060 0x8086, 0x1960
The lspci -n command can be used to display the IDs for adapters installed in a particular machine. Products with these IDs are known by (but not limited to) the following model names:
Dell PERC (dual-channel fast/wide SCSI) RAID controller
Dell PERC2/SC (single-channel Ultra SCSI) RAID controller
Dell PERC2/DC (dual-channel Ultra SCSI) RAID controller
Dell CERC (four-channel ATA/100) RAID controller
MegaRAID Express 500
HP NetRAID 3Si and 1M
Both Dell and LSI Logic have indicated that they no longer support these models in the 2.6 kernel. As a result, these adapters are no longer supported in Red Hat Enterprise Linux 4 Update 1.
Red Hat Enterprise Linux 4 Update 1 provides support for disk devices that are larger than 2 terabytes (TB). Although there is limited support for this feature in the Red Hat Enterprise Linux 4 release, Update 1 contains many improvements (both in user space programs and in the kernel). In general, Update 1 is considered a requirement for support of disk devices larger than 2 TB.
Please note the following guidelines and restrictions related to large device support:
· Typical disk devices are addressed in units of 512 byte blocks. The size of the address in the SCSI command determines the maximum device size. The SCSI command set includes commands that have 16-bit block addresses (device size is limited to 2 GB), 32-bit block addresses (limited to addressing 2 TB), and 64-bit block addresses. The SCSI subsystem in the 2.6 kernel has support for commands with 64-bit block addresses. To support disks larger then 2 TB, the Host Bus Adapter (HBA), the HBA driver, and the storage device must also support 64-bit block address. Red Hat has tested the QLogic qla2300 driver and the Emulex lpfc driver, included in Red Hat Enterprise Linux 4 Update 1, on an 8 TB logical unit on a Winchester Systems FX400 (rev. 3.42B and above is required).
· The commonly-used MS-DOS partition table format can not be used on devices larger than 2 TB. For devices larger than 2 TB, the GPT partition table format must be used. The parted utility must be used for the creation and management of GPT partitions. To create a GPT partition, use the parted command mklabel gpt.
Red Hat requires that all block devices be initialized with a valid partition table, even if there is a single partition encompassing the entire device. This requirement exists to prevent potential problems caused by erroneous or unintended partition tables on the device.
· The Anaconda installer currently only supports GPT partition tables on the Itanium™ architecture. As a result, it is not possible to install or format devices that are larger that 2 TB with Anaconda, except on Itanium™ platforms.
· The / and /boot directories must be located on devices that are 2 TB in size or less.
· Various issues with LVM2 on large devices are fixed in Red Hat Enterprise Linux 4 Update 1. Do not use LVM2 on devices larger than 2 TB prior to installing Update 1.
As noted above, Red Hat requires that a partition table be written to the block device, even when it is used as part of an LVM2 Volume Group. In this case, you may create a single partition that spans the entire device. Then, be sure to specify the full partition name (for example, /dev/sda1, not /dev/sda), when you use the pvcreate and vgcreate commands.
· The maximum size disk that can be a member of an md software RAID set is 2 TB. The md RAID device itself can be larger than 2 TB. Red Hat has tested md devices up to 8 TB.
· Various issues with e2fsprogs that occur on devices larger than 4 TB are addressed in Red Hat Enterprise Linux 4 Update 1. Prior to Update 1, these issues can be worked around by specifying mke2fs -b 4096 when making an ext2 or ext3 filesystem. The workaround is not necessary in Update 1.
The ext2 and ext3 filesystems have an internal limit of 8 TB. Devices up to this limit have been tested in Red Hat Enterprise Linux 4 Update 1.
You may want to use the mke2fs -T largefile4 command to speed up the creation of large filesystems.
· The GFS filesystem is limited to 16 TB on 32-bit systems, and 8 exabytes (EB) with 64-bit systems. Red Hat has tested GFS filesystem sizes up to 8 TB.
· NFS partitions greater than 2 TB have been tested and are supported.
· Red Hat Enterprise Linux 4 Update 1 user space tools are compiled for large file support. However, it is not possible to test every program in this mode. Please file a problem report if issues arise when using the tools for large file support.
· The inn program does not function correctly with devices larger than 2 TB. This will be addressed in a future release of Red Hat Enterprise Linux.
This section contains listings of packages that have been updated or added from Red Hat Enterprise Linux 4 as part of Update 1.
These package lists include packages from all variants of Red Hat Enterprise Linux 4. Your system may not include every one of the packages listed here.
The following packages have been updated from the original release of Red Hat Enterprise Linux 4:
The following new packages have been added to Red Hat Enterprise Linux 4 Update 1:
The following packages have been removed from Red Hat Enterprise Linux 4 Update 1:
No packages have been removed.
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