Veritas Volume Manager 5.0 Administrator's Guide (September 2006)

140 Administering dynamic multipathing (DMP)
Administering DMP using vxdmpadm
# vxdmpadm setattr path c1t20d0 pathtype=nopreferred
■ preferred [priority=N]
Specifies a path as preferred, and optionally assigns a priority number to it. If
specified, the priority number must be an integer that is greater than or equal to one.
Higher priority numbers indicate that a path is able to carry a greater I/O load.
Note: Setting a priority for path does not change the I/O policy. The I/O policy must
be set independently as described in “Specifying the I/O policy” on page 141.
This example first sets the I/O policy to priority for an Active/Active disk array,
and then specifies a preferred path with an assigned priority of 2:
# vxdmpadm setattr enclosure enc0 iopolicy=priority
# vxdmpadm setattr path c1t20d0 pathtype=preferred \
priority=2
■ primary
Defines a path as being the primary path for an Active/Passive disk array. The
following example specifies a primary path for an A/P disk array:
# vxdmpadm setattr path c3t10d0 pathtype=primary
■ secondary
Defines a path as being the secondary path for an Active/Passive disk array. This
example specifies a secondary path for an A/P disk array:
# vxdmpadm setattr path c4t10d0 pathtype=secondary
■ standby
Marks a standby (failover) path that it is not used for normal I/O scheduling. This
path is used if there are no active paths available for I/O. The next example specifies
a standby path for an A/P-C disk array:
# vxdmpadm setattr path c2t10d0 pathtype=standby
Displaying the I/O policy
To display the current and default settings of the I/O policy for an enclosure, array or array
type, use the
vxdmpadm getattr command.
The following example displays the default and current setting of iopolicy for JBOD
disks:
# vxdmpadm getattr enclosure Disk iopolicy
ENCLR_NAME DEFAULT CURRENT
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Disk MinimumQ Balanced