VERITAS Volume Manager 4.1 Administrator's Guide

Administering Dynamic Multipathing (DMP)

Administering DMP Using vxdmpadm

Chapter 3140

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 balanced MinimumQ

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 (A/A for Active/Active, or A/P for Active/Passive).