When a path recovers from an error, HDLM can automatically place the recovered path back online. This function is called the automatic failback function. In order to use the automatic failback function, HDLM must already be monitoring error recovery on a regular basis.
When non-owner paths exist, HDLM will select the path to be used next from the online owner paths, and then from the online non-owner paths. When a non-owner path is used because all of the owner-paths are placed offline, if an owner path recovers from an error and HDLM automatically places the recovered path online, the path will be automatically switched over from the non-owner path to the owner path that recovered from the error.
When intermittent errors# occur on paths and you are using the automatic failback function, the path status might frequently alternate between the online and offline statuses. In such a case, because the performance of I/Os will most likely decrease, if there are particular paths in which intermittent errors might be occurring, we recommend that you set up intermittent error monitoring so you can detect these paths, and then remove them from those subject to automatic failbacks.
You can specify the automatic failback function or intermittent error by the dlnkmgr command's set operation. For details on the set operation, see set (sets up the operating environment).