Provided by: multipath-tools_0.7.9-3ubuntu4_amd64
dmmp_path_group_id_get - Retrieve path group ID.
uint32_t dmmp_path_group_id_get (struct dmmp_path_group *dmmp_pg);
dmmp_pg Pointer of 'struct dmmp_path_group'. If this pointer is NULL, your program will be terminated by assert.
Retrieve the path group ID which could be used to switch active path group via command: multipathd -k'switch multipath mpathb group $id'