HP Veritas Volume Manager 5.0 -UX 11i v3 Displaying the I/O policy, Specifying the I/O policy

Administering dynamic multipathing (DMP) 147

Administering DMP using vxdmpadm

■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

The next example displays the setting of partitionsize for the enclosure enc0, on which the balanced I/O policy with a partition size of 2MB has been set:

#vxdmpadm getattr enclosure enc0 partitionsize

ENCLR_NAME DEFAULT CURRENT

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enc0 1024 2048

Specifying the I/O policy

You can use the vxdmpadm setattr command to change the I/O policy for distributing I/O load across multiple paths to a disk array or enclosure. You can set policies for an enclosure (for example, HDS01), for all enclosures of a particular type (such as HDS), or for all enclosures of a particular array type (such as A/A for Active/Active, or A/P for Active/Passive).