The blocked path monitoring setting allows you to specify the time (in seconds) for the system to monitor blocked paths. The range is from 2 to 45 seconds. The default is 40 seconds.
If all paths become monitored because of a path error, an I/O timeout might occur in the host. Therefore, the time you specify must be less than the host's I/O timeout setting.
If iSCSI is used in a remote path, the blocked path monitoring option must be set to at least 40 seconds (default). If blocked path monitoring is less than 40 seconds, the path might be blocked due to a delay in the network such as many switches in a spanning tree protocol (STP) network or a long distance connection.