4 Release Notes for Oracle Linux on Exalogic

The Oracle Linux operating system is pre-installed on the compute nodes of the Exalogic machine. This chapter lists the known issues in Oracle Linux on Exalogic.

This chapter contains the following sections:

4.1 General Information

You can ignore the following messages that are displayed when you install or boot Oracle Linux:"

  • The following error message appears on each Oracle Linux boot:

    • Starting mlx4_vnic_confd: Configuration file does not exist: /etc/infiniband/mlx4_vnic.conf [[FAILED]|pages/createpage.action?spaceKey=JRPG&title=FAILED&linkCreation=true&fromPageId=15410642]

      This error is benign.

    • grep: /sys/class/net/bond1/bonding/slaves: No such file or directory/etc/sysconfig/network-scripts/ifup-eth: line 99: /sys/class/net/bond1/bonding/slaves: No such file or directory

      Two instances of the above will occur each time open-ib boots. These messages do not prevent the image from functioning.

  • The following error appears during Oracle Linux PXE install and is captured in the install.log file:

    Installing kernel-uek-2.6.32-200.21.1.el5uek.x86_64
     
    WARNING: No module ehci-hcd found for kernel
     
    2.6.32-200.21.1.el5uek, continuing anyway
     
    WARNING: No module ohci-hcd found for kernel
     
    2.6.32-200.21.1.el5uek, continuing anyway
     
    WARNING: No module uhci-hcd found for kernel
     
    2.6.32-200.21.1.el5uek, continuing anyway
    

4.2 General Issues and Workarounds

This section describes general issues and workarounds for Oracle Linux:

4.2.1 File Owner Shown as nobody When Shared Drive Is Mounted with NFSv4

On the Oracle Linux operating system, when you mount a shared drive with NFSv4 as the file system protocol on the client side, the ownership of any previously created files is shown as nobody. To avoid this problem, use an NIS or LDAP Server to configure name services associated with the user on Exalogic compute nodes running Oracle Linux.

4.2.2 The limits.conf File May Contain Invalid Entries

If the soft nofile parameter in the /etc/security/limits.conf file on Oracle Linux contains a value of XS65536, change the value to 65536 manually, save, and close.

4.2.3 Need to Remount File Systems After System Reboots When NFSv4 Is Used

When you use NFSv4, you are required to re-mount all file systems by running the mount -a command on Oracle Linux each time you reboot the compute node.

To automatically re-mount the file systems rebooting a compute node running Oracle Linux, complete the following steps:

  1. Log in to the compute node as a root user.

  2. Create a script named nfs4_automount_on_init.sh in /etc/init.d/ directory (Log in as root user)

    # vi /etc/init.d/ nfs4_automount_on_init.sh

  3. Add the following to the script:

    #!/bin/bash
    #chkconfig: 345 80 05
    #description: NFSv4 Automount
    case "$1" in
        "start")
        mount -a
        ;;
        "stop")
        ;;
    esac
    

    Note:

    In chkconfig: 345 80 05, the first number 345 indicates the runLevels. The second number 80 is the start priority, and the third number 05 is the stop priority. The second number and the third number should be unique among all registered services, so you may need to adjust the values for your environment, if you have installed any other services.

  4. Set up executable permission on the script:

    # chmod +x /etc/init.d/ nfs4_automount_on_init.sh

  5. Run the following command to register the script:

    # chkconfig --add /etc/init.d/nfs4_automount_on_init.sh

  6. Optionally, run the following command to verify the registration of the script:

    # chkconfig --list

4.2.4 Multicasting in Multi-Homed Environments for Oracle Linux

Exalogic compute nodes are multi-homed. They have multiple network interfaces, each in a different LAN segment.

Upon IP configuration, these interfaces initiate a static route to their respective subnets. For all other networks, a default route is used. Multicasting also follows the system-wide routing table. By default, multicast packets are sent over the default route because it is a class D network.

If you want to enforce multicasting over a specific interface or network, you must add a route manually.

To multicast over the bond0 (IPoIB) interface, complete the following steps:

As a root user, run the following command on the command line:

route add -net 224.0.0.0 netmask 240.0.0.0 dev bond0

To make it persistent across reboots, create the /etc/sysconfig/network-scripts/route-bond0 file with the following content:

224.0.0.0/4 dev bond0

To verify, you can use the netstat command as follows:

netstat -rn

Example:

Kernel IP routing table
Destination     Gateway     Genmask      Flags      MSS Window     irtt Iface
192.168.10.0    0.0.0.0     255.255.255.0  U        0 0            0 bond0
10.204.80.0     0.0.0.0     255.255.254.0  U        0 0            0 eth0
224.0.0.0       0.0.0.0     240.0.0.0      U        0 0            0 bond0
0.0.0.0         10.204.80.1 0.0.0.0        UG       0 0            0 eth0