HDLM can check the status of paths for which I/O operations are not being performed at regular intervals. This function is called path health checking.
Without path health checking, an error is not detected unless I/O is performed because the system only checks the path status when I/O is performed. With path health checking, however, the system checks the status of online paths at regular intervals regardless of whether I/O is performed. If an error is detected in a path, path health checking functionality switches the status of that path to Offline(E) or Online(E), so you can use the dlnkmgr command's view operation to check the path error.
For example, in a normal state, I/O operations are not performed on the paths coming from the standby host in the cluster configuration or on non-owner paths#. Because of this, for the standby host or for a host connected to non-owner paths, we recommend that you use path health checking to detect errors. This enables the system to use the most up-to-date path-status information when selecting the next path to use.
You can configure path health checking by executing the dlnkmgr command's set operation. For details on the set operation, see set (sets up the operating environment).