Path failover occurs when the active path to a LUN is changed from one path to another, usually because of a SAN component failure along the current path.

When a path fails, storage I/O might pause for 30 to 60 seconds until your host determines that the link is unavailable and completes failover. If you attempt to display the host, its storage devices, or its adapters, the operation might appear to stall. Virtual machines with their disks installed on the SAN can appear unresponsive. After failover is complete, I/O resumes normally and the virtual machines continue to run.

However, when failovers take a long time to complete, a Windows virtual machine might interrupt the I/O and eventually fail. To avoid the failure, set the disk timeout value for the Windows virtual machine to at least 60 seconds.