Enabling multipathing for Linux hosts

You can enable the system to support multipathing for Linux hosts.

The system supports the Linux device-mapper multipathing driver for the iSCSI host attachment. After the iSCSI devices are discovered, you can enable multipathing.
To enable multipathing for a Linux host, complete the following steps:
  1. If the daemon is already running, stop the multipathing daemon with the service multipathd stop command.
  2. Add the entry for the system by editing the multipath configuration file, /etc/multipath.conf. In the DMMP configuration file, /etc/multipath.conf, ensure that the default settings include the values described in Settings for Linux hosts
    Note: Prevent blacklisting of the IBM 2145 devices by either disabling blacklisting of devices entirely or by adding an appropriate entry in the blacklist_exceptions section.
  3. Save the file.
  4. Restart the multipathing daemon with the service multipathd start command.

    If you are using SUSE Linux Enterprise Server 10 Service Pack 2 or later, replace the line prio "/sbin/mpath_prio/alua /dev/%n" with prio "alua" to disable the Using deprecated prio message.

    Note: Linux™ usually enables multipathing automatically. However, in some cases such as the RH 6.3 SAN boot installation, the multipathing is not configured properly. If this situation occurs, you must manually edit the /etc/multipath.conf file. For more information about DM-multipath, see the Linux™ Storage Administration Guide or DM-Multipathing Installation and Configuration Guide for your kernel from the Linux™ provider. For more information about Linux™ system configuration, see the following website:

    http://www.ibm.com/support/knowledgecenter/linuxonibm/liaab/ic-homepage.htm