Q: What policies configure iSCSI Multipath I/O (MPIO) behavior?

Failover only is used to provide additional availability should a connection fail, but does not provide load balancing or network aggregation.

Round robin is the default setting for most connections. It aggregates network connections, sending data equally across each connection.

Round robin with a subset of paths adds one or more additional failover adapters, which are only used when each member of the round robin group has failed.

Least queue depth also provides for network aggregation, but sends each I/O request through the connection with the least number of requests in queue.

Weighted paths provides network aggregation, but adds the ability to manually assign weights to different paths. These weights determine how heavily each connection is used in comparison with the others.

Least blocks is similar to least queue depth in that it unevenly distributes I/O requests; however this policy sends each I/O request through the connection with the least number of pending I/O blocks.