The image below is an example of the I/O operations where an I/O delay has occured on the slice of a single volume with panic mode is activated.
If the specified I/O response time is exeeded, the I/O of disk1 will time out and the GDS I/O Monitor Option will panic the system. Because of this the cluster will fail over.The time necessary for failover is less than if the system panic mode is set to disabled.
For cluster systems, it is recommended to set the system panic mode to enabled.
Figure 8.3 I/O Response Time Assurance (When an I/O response delay occurs on the slice of a single volume)
GDS: Global Disk Services
Information
If system panic mode is set to disabled, if an I/O response delay or I/O error occurs on all the slices making up the mirror system, or if the class was closed, an error occurs in the volume stop processing on the previous operating node while cluster failover processing is being done and because of the double fault RMS panics the previous operating node.
