All drive are down驱动器自动down

Question

每次都是在成功备份完之后，umount media，驱动器就down了。日子如下：
10:00:20.193 [19732] <2> nb_bind_on_port_addr: bound to port 49347
10:00:20.194 [19732] <2> logconnections: BPDBM CONNECT FROM 10.20.0.36.49347 TO 10.20.0.36.13721
10:00:20.194 [19732] <2> vauth_authentication_required: vauth_comm.c.792: no methods for address: no authentication required
10:00:20.194 [19732] <2> vauth_connector: vauth_comm.c.192: no methods for address: no authentication required
10:00:20.194 [19732] <2> check_authentication: no authentication required
10:00:20.195 [19732] <2> vnet_check_vxss_client_magic_with_info: vnet_vxss_helper.c.775: Ignoring VxSS authentication: 2 0x00000002
10:00:20.195 [19732] <2> vnet_check_vxss_client_magic_with_info: vnet_vxss_helper.c.931: Not using VxSS authentication: 2 0x00000002
10:00:20.475 [19732] <4> write_backup: successfully wrote backup id hht_app2_1305683939, copy 1, fragment 1, 112032 Kbytes at 32911.868 Kbytes/sec
10:00:20.475 [19732] <2> notify: executing - /usr/openv/netbackup/bin/backup_notify bptm hht_app2_1305683939
10:00:20.521 [19732] <2> bptm: EXITING with status 0 <----------
10:00:22.329 [20158] <2> bptm: INITIATING (VERBOSE = 5): -count -cmd -rt 8 -rn 0 -stunit hht_app2-hcart2-robot-tld-0 -den 14 -mt 2 -masterversion 500000
10:00:22.329 [20158] <2> bptm: EXITING with status 0 <----------
10:03:45.587 [21114] <2> bptm: INITIATING (VERBOSE = 5): -U
10:03:45.588 [21114] <2> db_byid: search for media id X134L2
10:03:45.588 [21114] <2> db_byid: X134L2 found at offset 0
10:03:45.588 [21114] <2> tpunmount_all: tpunmount'ing /usr/openv/netbackup/db/media/tpreq/X134L2
10:03:45.598 [21114] <2> TpUnmountWrapper: SCSI RELEASE
10:03:45.631 [21114] <2> bptm: EXITING with status 0 <----------
10:03:48.198 [21128] <2> bptm: INITIATING (VERBOSE = 5): -delete_expired
10:03:48.198 [21128] <2> bptm: EXITING with status 0 <----------
10:06:12.679 [21785] <2> bptm: INITIATING (VERBOSE = 5): -count -cmd -rt 8 -rn 0 -stunit hht_app2-hcart2-robot-tld-0 -den 14 -mt 2 -masterversion 500000
10:06:12.683 [21785] <4> bptm: all drives are down for the specified robot number = 0, robot type = TLD and density = hcart2
10:06:12.683 [21785] <2> bptm: EXITING with status 0 <----------
10:16:12.697 [24555] <2> bptm: INITIATING (VERBOSE = 5): -count -cmd -rt 8 -rn 0 -stunit hht_app2-hcart2-robot-tld-0 -den 14 -mt 2 -masterversion 500000
10:16:12.700 [24555] <4> bptm: all drives are down for the specified robot number = 0, robot type = TLD and density = hcart2
10:16:12.701 [24555] <2> bptm: EXITING with status 0 <----------