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2.3. Known Issues

  • 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 Storage.
    If the adapter is incorrectly set to "I2O" emulation, the system will attempt to load the i2o driver. This will fail, and prevent the proper driver from being loaded.
    Previous Red Hat Enterprise Linux releases generally do not attempt to load the I2O driver before the MegaRAID driver. Regardless of this, the hardware should always be set to "Mass Storage" emulation mode when used with Linux.
  • Red Hat Enterprise Linux 5 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 of time.
    For updated versions of openmpi, please check
  • Installing Windows Server 2003 as a guest on a fully virtualized Red Hat Enterprise Linux 5 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 will be resolved in an upcoming Red Hat Enterprise Linux 5 update. To work around this, use the following command at the terminal:
    xm create /etc/xen/<name of guest machine>
    Afterwards, open the virtual machine.
  • When attempting to create a fully virtualized Windows Server 2003 from a CD / DVD, the second stage of the guest install will not continue upon reboot.
    To work around this, edit /etc/xen/<name of guest machine> by properly appending an entry for the CD / DVD device.
    If an installation to a simple file is used as a virtual device, the disk line of /etc/xen/<name of guest machine> will read like the following:
    disk = [ 'file:/PATH-OF-SIMPLE-FILE,hda,w']
    A DVD-ROM device located on the host as /dev/dvd can be made available to stage 2 of the installation as hdc by appending an entry like 'phy:/dev/dvd,hdc:cdrom,r'. As such, the disk line should now read as follows:
    disk = [ 'file:/opt/win2003-sp1-20061107,hda,w', 'phy:/dev/dvd,hdc:cdrom,r']
    The precise device path to use may vary depending on your hardware.
  • rmmod xennet causes domU to crash; this is caused by a grant table issue in the Virtualization feature. Due to the current inability of the Virtualization feature to asynchronously release grant table operations, it is unsafe to unload the xennet module in guests. In such situations, grant tables are used to perform backend-frontend communication, and there is no guarantee that the backend will release the references, leading to an inevitable memory leak.
    This issue will be resolved in the next minor release of Red Hat Enterprise Linux 5. At present, users are advised not to unload the xennet module in guests.
  • Running ethtool eth0 outputs incomplete information about the ethernet card settings. This only occurs in systems running a virtualized kernel, since the Virtualization feature uses a networking setup where the physical ethernet device is identified as peth0. As such, the correct command for retrieving information about the physical ethernet device is ethtool peth0.
  • When using Red Hat Enterprise Linux 5 on a machine with an nVidia CK804 chipset installed, you may receive kernel messages similar to the following:
    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. Further, these messages do not, in any way, affect the operation of the machine.
  • Some Cisco Aironet Wireless devices prevent NetworkManager from storing connection details for wireless networks that do not broadcast an SSID. This is caused by a Cisco Aironet Wireless device firmware limitation.
  • Laptops that have the Cisco Aironet MPI-350 wireless card equipped 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).
  • Currently, system-config-kickstart does not support package selection and deselection. When using system-config-kickstart, the Package Selection option indicates that it is disabled. This is because system-config-kickstart uses yum to gather group information, but is unable to configure yum to connect to Red Hat Network.
    This issue is currently being investigated for resolution by the next minor release of Red Hat Enterprise Linux 5. At present, you need to update package sections in your kickstart files manually. When using system-config-kickstart to open a kickstart file, it will preserve all package information in it and write it back out when you save.
  • 4-socket AMD Sun Blade X8400 Server Module systems that do not have memory configured in node 0 will panic during boot. Systems should be configured with memory in node 0 to prevent the kernel panic.
  • Installing to LVM mirror devices through Anaconda is currently not supported. This capability will be added in a future update of Red Hat Enterprise Linux 5.
  • When installing Red Hat Enterprise Linux 5 from a directory on an NFS server containing Red Hat Enterprise Linux ISO images, Anaconda may display the following error message:
    Unable to read package metadata. This may be due to a missing repodata directory. 
    Please ensure that your install tree has been correctly generated. Cannot 
    open/read repomd.xml file for repository:
    This problem occurs if the directory holding the ISO images also contains a partially unpacked installation tree (for example, the /images directory from the first ISO). The presence of such directories results in the error stated above.
    To prevent this error, unpack trees only to directories other than the one containing the installation ISO images.
  • Boot-time logging to /var/log/boot.log is not available in this release of Red Hat Enterprise Linux 5. An equivalent functionality will be added in a future update of Red Hat Enterprise Linux 5.
  • Neither kexec nor kdump are able to dump onto disks attached to an accraid controller.
    To work around this issue, use scp for network dumping. Alternatively, you can also dump onto a disk through a different controller.
  • Installing a fully virtualized guest using split installation media -- specifically, multiple CD-ROMs -- may fail when required to switch between installation CDs. During the guest OS installation process, users may be prevented from mounting or ejecting installation CDs, which prevents the installation from completing.
    As such, it is recommended that you use the QEMU monitor console to switch CD-ROM images during the guest OS installation process. The procedure is as follows:
    1. Open a graphical VNC console to the guest OS.
    2. Unmount the CD-ROM device in the guest OS.
    3. Switch to the QEMU monitor console by pressing Ctrl-Alt-2.
    4. Run the command eject hdc.
    5. Run the command change hdc <path to the CD-ROM in host system>.
    6. Switch back to the guest OS console by pressing Ctrl-Alt-1.
    7. Mount the CD-ROM device in the guest OS.
    Note that when using a regular VNC client the host X server may encounter some difficulty interpreting the Ctrl-Alt-2 and Ctrl-Alt-1 command. To work around this in virt-manager, use sticky keys. Pressing Ctrl three times makes it "sticky" until the next non-modifier is pressed. As such, to send Ctrl-Alt-1, press Ctrl twice before pressing Ctrl-Alt-1.
  • The Red Hat Enterprise Linux 5 Driver Update Model creates modified initrd images whenever a kmod package that includes a bootpath-modifying driver is installed. In time, the number of backup initrd images may soon fill the /boot partition, particularly if the system undergoes a sizeable number of driver updates.
    As such, it is recommended that you monitor the free space on the /boot partition if you regularly perform driver updates. You can free up more space in /boot by removing older initrd images; these files end in .img0, .img1, .img2, and so on.
  • Autorun on removable media is currently disabled. To install packages from the Red Hat Enterprise Linux Supplementary CD, launch the CD installer manually using the following command:
    system-cdinstall-helper /media/path-to-mounted-drive
  • When upgrading from Red Hat Enterprise Linux 4 to Red Hat Enterprise Linux 5, the Deployment Guide is not automatically installed. You need to use pirut to manually install it after completing the upgrade.
  • An autofs bug prevents multi-mounts from working properly.
    During an expiry, if the last multi-mount component to be checked does not have a mount associated with it while other components are busy, autofs erroneously determines the multi-mount to be expirable. This causes the multi-mount to be partially expired, resulting in the multi-mount becoming unresponsive to further mount requests and expire runs.
    To permanently resolve this problem, update autofs using the command yum update autofs.
  • 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.