You can specify the use_all_paths attribute in conjunction with the adaptive, balanced, minimumq, priority and round-robin I/O policies to specify whether I/O requests are to be scheduled on the secondary paths in addition to the primary paths of an Asymmetric Active/Active (A/A-A) array. Depending on the characteristics of the array, the consequent improved load balancing can increase the total I/O throughput. However, this feature should only be enabled if recommended by the array vendor. It has no effect for array types other than A/A-A.
For example, the following command sets the balanced I/O policy with a partition size of 4096 blocks (2MB) on the enclosure enc0, and allows scheduling of I/O requests on the secondary paths:
# vxdmpadm setattr enclosure enc0 iopolicy=balanced \ partitionsize=4096 use_all_paths=yes
The default setting for this attribute is use_all_paths=no.
You can display the current setting for use_all_paths for an enclosure, arrayname or arraytype. To do this, specify the use_all_paths option to the vxdmpadm gettattr command.
# vxdmpadm getattr enclosure HDS9500-ALUA0 use_all_paths
ENCLR_NAME DEFAULT CURRENT =========================================== HDS9500-ALUA0 no yes
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.