5.6. Issues with queue_if_no_path feature

If a multipath device is configured with features "1 queue_if_no_path", then any process that issues I/O will hang until one or more paths are restored. To avoid this, set the no_path_retry N parameter in the /etc/multipath.conf file (where N is the number of times the system should retry a path).

Setting the no_path_retry parameter overrides the feature option features "1 queue_if_no_path", even if this features option is set in the devices section and no_path_retry is set in the defaults section of the multipath configuration file.

If you need to use the features "1 queue_if_no_path" option and you experience the issue noted here, use the dmsetup command to edit the policy at runtime for a particular LUN (that is, for which all the paths are unavailable). For example, if you want to change the policy on the multipath device mpathc from "queue_if_no_path" to "fail_if_no_path", execute the following command.

dmsetup message mpathc 0 "fail_if_no_path"

Note that you must specify the mpathn alias rather than the path.