 | ||
| Load balancing | ||
|---|---|---|
| Prev | Administering dynamic multipathing (DMP) | Next |
By default, DMP uses a minimum queue length policy (minimumq) to provide load balancing across paths for Active/Active disk arrays. I/O is sent down the path that has the minimum number of outstanding I/O requests in the queue for a LUN.
For Active/Passive and Asymmetric Active/Active disk arrays, the default round-robin policy shares I/O equally between the available paths in a round-robin sequence. If the primary path fails, I/O is switched over to another available primary or secondary path. As the continuous transfer of ownership of LUNs from one controller to another results in severe I/O slowdown, load balancing across paths is not performed for Active/Passive disk arrays unless they support concurrent I/O.
You can use the vxdmpadm command to change the I/O policy for the paths to an enclosure or disk array.