Request—For native devices, this policy uses the path that would have been used if PowerPath were not installed. For
pseudo devices, it uses one arbitrary path for all I/O. For all devices, path failover is in effect, but load balancing is not.
No Redirect—Neither load balancing or failover is in effect. If this algorithm is set on a failed path and a native device is
used, I/O errors will occur when I/O is directed to that path. This policy is valid only on Symmetrix arrays.
Basic failover—Load balancing is not in effect. I/O routing on failure is limited to one host bus and one port on each
Storage Processor. This policy is required for a non-disruptive upgrade. It protects against Storage Processor and back-end
failures, but not against HBA or host loop failures. PowerPath is required to prevent HBA and/or host loop failures.
