--Father job jobdetailes:It select the last storage unit from storage group;
02/06/2012 10:21:41 - requesting resource storage1
02/06/2012 10:21:41 - requesting resource eric.NBU_CLIENT.MAXJOBS.client222
02/06/2012 10:21:41 - requesting resource eric.NBU_POLICY.MAXJOBS.oracle
02/06/2012 10:21:41 - granted resource  eric.NBU_CLIENT.MAXJOBS.client222
02/06/2012 10:21:41 - granted resource  eric.NBU_POLICY.MAXJOBS.oracle
02/06/2012 10:21:41 - granted resource  eric-hcart-robot-tld-1
02/06/2012 10:21:41 - estimated 0 kbytes needed
02/06/2012 10:21:42 - started process bpbrm (pid=15184)
02/06/2012 10:21:42 - connecting
02/06/2012 10:21:44 - connected; connect time: 0:00:00
02/06/2012 10:56:17 - end writing
the requested operation was successfully completed  (0)
--From sub job jobdetailes:It select the first storage unit from storage group;
02/06/2012 10:21:57 - requesting resource storage1
02/06/2012 10:21:57 - requesting resource eric.NBU_CLIENT.MAXJOBS.client222
02/06/2012 10:21:57 - requesting resource eric.NBU_POLICY.MAXJOBS.oracle
02/06/2012 10:21:57 - granted resource  eric.NBU_CLIENT.MAXJOBS.client222
02/06/2012 10:21:57 - granted resource  eric.NBU_POLICY.MAXJOBS.oracle
02/06/2012 10:21:57 - granted resource  5004L4
02/06/2012 10:21:57 - granted resource  STK.T9840B.000
02/06/2012 10:21:57 - granted resource  eric-hcart-robot-tld-0
02/06/2012 10:21:57 - estimated 0 kbytes needed
02/06/2012 10:22:00 - started process bpbrm (pid=15239)
02/06/2012 10:22:01 - connecting
02/06/2012 10:22:12 - connected; connect time: 0:00:00
02/06/2012 10:22:16 - mounting 5004L4
02/06/2012 10:22:24 - mounted 5004L4; mount time: 0:00:08
02/06/2012 10:22:24 - positioning 5004L4 to file 4
02/06/2012 10:22:24 - positioned 5004L4; position time: 0:00:00
02/06/2012 10:22:24 - begin writing
02/06/2012 10:29:17 - end writing; write time: 0:06:53
the requested operation was successfully completed  (0)
--But check the unified log,we found that the sub job select the STU filter type to STU_FILTER_BKUP_FAILOVER when it get STU list,father job don't select STU filter type,it only select the last of the storage unit from the STU list.
    --From sub job unified log:
02/06/2012 10:21:57.297 [select_for_bkup] checking for storage units in storage unit group, name = storage1
02/06/2012 10:21:57.297 [get_stu_list] stu_filter_type = STU_FILTER_BKUP_FAILOVER, exclude_stu_type_mask = 0,mode = CONSIDER_DRIVE_MEDIA_AVAILABILITY
......................................................
02/06/2012 10:21:57.336 [sql_select_unloaded_media] media_status_mode = MEDIA_STATUS_DEFAULT, media_type_mode = TYPE_ASSIGNED, count_media = 0
02/06/2012 10:21:57.336 [include_serv_grp_media] str =  EMM_Media.ServerGroupKey IN (7000002) AND ((EMM_Media.ServerGroupKey = 7000002 AND EMM_Media.LastWriteHostKey = 1000002) OR (EMM_Media.ServerGroupKey != 7000002)) AND
02/06/2012 10:21:57.343 [sql_density_name2type] density_name = NBU    HIC1
02/06/2012 10:21:57.344 [sql_density_name2type] density type = 6
02/06/2012 10:21:57.344 [sql_select_unloaded_media] SELECTED MEDIA - media_t: id = 5004L4, key = 4000004, partner_key = 0, ass_time = 1328492124, alloc_state = 0, pool_name = test, pool_num = 6, robot_num = 0, robot_type = 8, type_name = NetBackup HCART1, density_name = NBU    HIC1, status = 0, conflicts = 0, drive_key = 0, last_whost_key = 1000002, master_server_key = 1000002, server_group_key = 7000002
02/06/2012 10:21:57.344 [get_storage_unit_attributes] name = eric-hcart-robot-tld-0
    --From father job unified:
02/06/2012 10:21:41.301 [get_twin_media_server_and_stu] stu_list has 2 storage units
02/06/2012 10:21:41.301 [is_host_online] host_info_t: key = 1000002, parent_key = 1000002, fqname = eric, state = 14, nbversion = 700000, nbtype = 3, cluster_key = 0, cluster_fqname = , active_node_key = 0, flags = 119, raw_host_key = 1000002, raw_host_name = eric, rank = 3
02/06/2012 10:21:41.302 [is_host_online] host_info_t: key = 1000002, parent_key = 1000002, fqname = eric, state = 14, nbversion = 700000, nbtype = 3, cluster_key = 0, cluster_fqname = , active_node_key = 0, flags = 119, raw_host_key = 1000002, raw_host_name = eric, rank = 3
02/06/2012 10:21:41.302 [get_storage_unit_attributes] name = eric-hcart-robot-tld-1
02/06/2012 10:21:41.302 [get_storage_unit_attributes] master_serv - host_info_t: key = 1000002, parent_key = 1000002, fqname = eric, state = 14, nbversion = 700000, nbtype = 3, cluster_key = 0, cluster_fqname = , active_node_key = 0, flags = 119, raw_host_key = 1000002, raw_host_name = eric, rank = 3
02/06/2012 10:21:41.305 [getTwinMediaServerAndStu] twin_media_server = eric, STUName = eric-hcart-robot-tld-1