Veritas Volume Manager 5.1 SP1 Administrator"s Guide (5900-1506, April 2011)

The use_all_paths attribute only applies to A/A-A arrays. For other arrays, the
above command displays the message:
Attribute is not applicable for this array.
Example of applying load balancing in a SAN
This example describes how to configure load balancing in a SAN environment
where there are multiple primary paths to an Active/Passive device through
several SAN switches. As can be seen in this sample output from the vxdisk list
command, the device c3t2d15 has eight primary paths:
# vxdisk list c3t2d15
Device: c3t2d15
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numpaths: 8
c2t0d15 state=enabled type=primary
c2t1d15 state=enabled type=primary
c3t1d15 state=enabled type=primary
c3t2d15 state=enabled type=primary
c4t2d15 state=enabled type=primary
c4t3d15 state=enabled type=primary
c5t3d15 state=enabled type=primary
c5t4d15 state=enabled type=primary
In addition, the device is in the enclosure ENC0, belongs to the disk group mydg,
and contains a simple concatenated volume myvol1.
The first step is to enable the gathering of DMP statistics:
# vxdmpadm iostat start
Next the dd command is used to apply an input workload from the volume:
# dd if=/dev/vx/rdsk/mydg/myvol1 of=/dev/null &
By running the vxdmpadm iostat command to display the DMP statistics for the
device, it can be seen that all I/O is being directed to one path, c5t4d15:
# vxdmpadm iostat show dmpnodename=c3t2d15 interval=5 count=2
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185Administering Dynamic Multi-Pathing
Administering DMP using vxdmpadm