Dell EMC PowerVault MD 34XX/38XX Series Storage Arrays Administrator's Guide

The RAID controller firmware automatically transfers virtual disk ownership if more than 75 percent of data I/O over the previous five minutes was routed to the non-owning RAID controller. This indicates that either the storage array has lost redundant connections or that some of the data paths to the virtual disk or disk group are not usable. MD Storage Manager launches the Recovery Guru (Virtual Disk Not on Preferred Path) if the condition still exists after the default alert five-minute delay time has expired. For more information, see Recovery Guru.