Novell LINUX ENTERPRISE SERVER 11 - STORAGE ADMINISTRATION GUIDE 2-23-2010, Administration Manual, Page: 49 / 140

Managing Multipath I/O for Devices 49
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Consider the following caveats:
Š
Not all of the storage arrays that are automatically detected have been tested on SUSE Linux
Enterprise Server. For information, see
“Tested Storage Arrays for Multipathing Support” on
page 49 .
Š
Some storage arrays might require specific hardware handlers. A hardware handler is a kernel
module that performs hardware-specific actions when switching path groups and dealing with
I/O errors. For information, see
“Storage Arrays that Require Specific Hardware Handlers” on
page 49 .
Š After you modify the
/etc/multipath.conf
file, you must run
mkinitrd
to re-create the
INITRD on your system, then reboot in order for the changes to take effect.
Tested Storage Arrays for Multipathing Support
The following storage arrays have been tested with SUSE Linux Enterprise Server:
EMC
Hitachi
Hewlett-Packard/Compaq
IBM
NetApp
SGI
Most other vendors’ storage arrays should also work. Consult your vendor’s documentation for
guidance. For a list of the default storage arrays recognized by the
multipath-tools
package, see
“Storage Arrays That Are Automatically Detected for Multipathing” on page 48 .
Storage Arrays that Require Specific Hardware Handlers
Storage arrays that require special commands on failover from one path to the other or that require
special nonstandard error handling might require more extensive support. Therefore, the Device
Mapper Multipath service has hooks for hardware handlers. For example, one such handler for the
EMC CLARiiON CX family of arrays is already provided.
IMPORTANT: Consult the hardware vendor’s documentation to determine if its hardware handler
must be installed for Device Mapper Multipath.
The
multipath -t
command shows an internal table of storage arrays that require special handling
with specific hardware handlers. The displayed list is not an exhaustive list of supported storage
arrays. It lists only those arrays that require special handling and that the
multipath-tools
developers had access to during the tool development.
IMPORTANT: Arrays with true active/active multipath support do not require special handling, so
they are not listed for the
multipath -t
command.
A listing in the
multipath -t
table does not necessarily mean that SUSE Linux Enterprise Server
was tested on that specific hardware. For a list of tested storage arrays, see “Tested Storage Arrays
for Multipathing Support” on page 49 .