10400424-002 04/2013
©2013 Overland Storage, Inc.
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SnapSAN S3000/S5000 Path Manager Linux User Guide
Path Patrol Daemon
Basic Operation of the Path Patrol Daemon
The PathManager driver automatically performs path switching if a fault occurs. The driver
requires an external trigger to restore a faulty path. This trigger is given by the path patrol
daemon. You can also give this trigger using a maintenance command. The path patrol
daemon also monitors the paths. This makes it possible to detect a fault on the alternate
path.
If the path patrol daemon detects an indication of path status change when reading the proc
file system, it directs the driver to perform path repair and the other necessary processing.
Script for Operating the Path Control Daemon
For operation such as starting or stopping the path patrol daemon, use the script file
(/etc/rc.d/init.d/dd_daemon). Use this script file to stop monitoring by the path patrol daemon
for maintenance purposes and in the other cases.
Execute the script file specifying an argument string. The execution of this script requires
the root authority.
Arguments of the Path Patrol Daemon Operation Script
The example of executing the script file is shown as follows.
Root authority is necessary to execute the script file.
Monitoring Paths
The path patrol daemon monitors active paths and alternate paths at regular intervals.
When it detects a fault or recovering from fault, notices to the PathManager driver.
Setting of Monitoring Interval
There are some types of monitoring interval as follows. You can change the setting at Watch
entry in the configuration file (/etc/sps.conf).
Argument String
Operation
start
Start
stop
Stop
restart
Restart
status
Status display
