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The
command shows an internal table of storage arrays that require special handling
multipath -t
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
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
A listing in the
multipath -t
was tested on that specific hardware. For a list of tested storage arrays, see
for Multipathing Support" on page
5.3 Multipath Management Tools
The multipathing support in SUSE Linux Enterprise Server 10 is based on the Device Mapper
Multipath module of the Linux 2.6 kernel and the
use
to view the status of multipathed devices.
mdadm
Section 5.3.1, "Device Mapper Multipath Module," on page 49
Section 5.3.2, "Multipath I/O Management Tools," on page 51
Section 5.3.3, "Using mdadm for Multipathed Devices," on page 51
Section 5.3.4, "The Linux multipath(8) Command," on page 52
5.3.1 Device Mapper Multipath Module
The Device Mapper Multipath (DM-MP) module provides the multipathing capability for Linux.
DM-MP is the preferred solution for multipathing on SUSE Linux Enterprise Server 10. It is the
only multipathing option shipped with the product that is completely supported by Novell
SUSE.
DM-MP features automatic configuration of the multipathing subsystem for a large variety of
setups. Configurations of up to 8 paths to each device are supported. Configurations are supported
for active/passive (one path active, others passive) or active/active (all paths active with round-robin
load balancing).
The DM-MP framework is extensible in two ways:
Using specific hardware handlers. For information, see
Hardware Handlers" on page
Using more sophisticated load-balancing algorithms than round-robin
The user-space component of DM-MP takes care of automatic path discovery and grouping, as well
as automated path retesting, so that a previously failed path is automatically reinstated when it
becomes healthy again. This minimizes the need for administrator attention in a production
environment.
DM-MP protects against failures in the paths to the device, and not failures in the device itself. If
one of the active paths is lost (for example, a network adapter breaks or a fiber-optic cable is
removed), I/O is redirected to the remaining paths. If the configuration is active/passive, then the
path fails over to one of the passive paths. If you are using the round-robin load-balancing
command.
multipath -t
table does not necessarily mean that SUSE Linux Enterprise Server
48.
multipath-tools
48.
multipath-tools
"Tested Storage Arrays
userspace package. You can
"Storage Arrays that Require Specific
Managing Multipath I/O for Devices
®
and
49
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Troubleshooting
