Figure 9 When the Path Mode is Single Mode
•When the path mode is Single mode and there is at least one alternate path in the Standby status
Figure 10 (page 24) shows an example of when the path mode is Single mode, and there are alternate paths in Normal status and Standby status. Figure 11 (page 25) shows another example of when the path mode is Single mode. For Figure 11 (page 25), there are alternate paths in Standby status only.
When an error occurs in the path that is being used for I/Os, the I/O execution path is switched to the path with the second highest priority in Normal status (see Figure 10 (page 24)). If there is no path in Normal status other than the path that is being used for I/Os, the status of the path in Standby status is automatically changed to Normal, and the I/O execution path is switched to that path (see Figure 11 (page 25)).
As you restore the path with the highest priority, note that only when the external storage system is an EVA storage system, the I/O execution path is switched back to the restored highest priority path. In this case, the status of the path for which the status was changed to Normal when the error occurred changes back to Standby.
Configuring XP External Storage 23