IBM® supports the two largest commercial Linux distributions, Red Hat Enterprise Linux (RHEL) and SUSE Linux Enterprise Server (SLES). You can apply this information, in general, to other Linux distributions.
IBM supports various host bus adapters (HBAs) manufactured by QLogic, Emulex, and Brocade. These guidelines assume that the HBA was previously installed. For all newer versions of RHEL and SLES, use the Linux multipathing driver, Device-Mapper Multipath (DM Multipath). This section assumes DM Multipath is used. Use the HBA driver that is included with the distribution.
Before Red Hat Enterprise Linux 4 Update 6 and SUSE Linux Enterprise Server 9 SP3, the IBM Subsystem Device Driver (SDD) was the only multipathing option. For more information about SDD, see the IBM System Storage® Multipath Subsystem Device Driver User’s Guide at IBM Multipath Subsystem Device Driver User's Guide.
The procedures for attaching DS8000® storage are similar to the procedures for attaching most storage systems to Linux. There might be more than one way to complete each procedure. For more information about configuring storage on your specific Linux distribution, see your distribution documentation. For example, detailed information for Red Hat is provided in the Storage Administration Guide.
To locate one or more WWPNs, enter the following command:
# systool -c fc_host -A "port_name"
For multipathing on Red Hat Enterprise Linux 6, use the defaults that are compiled into DM Multipath.
For multipathing on earlier Linux releases, use the sample multipath.conf file that is provided on the IBM Subsystem Device Driver for Linux support page at IBM Subsystem Device Driver for Linux.
multipath.conf is a user-configurable file. The recommended settings are baseline recommendations and can be modified as needed.
This adds any new LUNs to the configuration. No reboot is required.
This expands or shrinks the LUN size. No reboot is required.