I maintain a persistent 3G connection on a remote device using network manager. However, every so often, the link fails and then does not restart itself. I managed to identify an occurrence of this in my syslog, but honestly I'm not really sure what I'm looking at. It seems that the machine thinks the device has been unplugged, but there's no corresponding log entry for it actually being unplugged.
Would someone mind looking at the below syslog snip and guiding me in the right direction?
Oct 13 22:25:26 tracker pppd[1091]: LCP terminated by peer Oct 13 22:25:26 tracker pppd[1091]: Connect time 206.7 minutes. Oct 13 22:25:26 tracker pppd[1091]: Sent 203306 bytes, received 182777 bytes. Oct 13 22:25:26 tracker pppd[1091]: Modem hangup Oct 13 22:25:26 tracker pppd[1091]: Connection terminated. Oct 13 22:25:26 tracker NetworkManager[333]: <info> (ttyUSB1): device state change: 8 -> 9 (reason 13) Oct 13 22:25:26 tracker NetworkManager[333]: <info> Unmanaged Device found; state CONNECTED forced. (see http://bugs.launchpad.net/bugs/191889) Oct 13 22:25:26 tracker NetworkManager[333]: <warn> Activation (ttyUSB1) failed. Oct 13 22:25:26 tracker modem-manager[337]: <info> (ttyUSB1) closing serial port... Oct 13 22:25:26 tracker NetworkManager[333]: <info> (ttyUSB1): device state change: 9 -> 3 (reason 0) Oct 13 22:25:26 tracker NetworkManager[333]: <info> (ttyUSB1): deactivating device (reason: 0). Oct 13 22:25:26 tracker kernel: [12441.840088] ata1.00: exception Emask 0x0 SAct 0x0 SErr 0x0 action 0x6 Oct 13 22:25:26 tracker kernel: [12441.846744] ata1.00: BMDMA stat 0x66 Oct 13 22:25:26 tracker kernel: [12441.850446] ata1.00: failed command: WRITE DMA Oct 13 22:25:26 tracker kernel: [12441.855020] ata1.00: cmd ca/00:02:c4:fb:5b/00:00:00:00:00/e0 tag 0 dma 1024 out Oct 13 22:25:26 tracker kernel: [12441.855024] res 51/84:00:c4:fb:5b/00:00:00:00:00/e0 Emask 0x30 (host bus error) Oct 13 22:25:26 tracker kernel: [12441.870623] ata1.00: status: { DRDY ERR } Oct 13 22:25:26 tracker kernel: [12441.874708] ata1.00: error: { ICRC ABRT } Oct 13 22:25:26 tracker kernel: [12441.878820] ata1: soft resetting link Oct 13 22:25:26 tracker modem-manager[337]: <info> (ttyUSB1) serial port closed Oct 13 22:25:26 tracker modem-manager[337]: <info> Modem /org/freedesktop/ModemManager/Modems/0: state changed (connected -> disconnecting) Oct 13 22:25:26 tracker modem-manager[337]: <info> Modem /org/freedesktop/ModemManager/Modems/0: state changed (disconnecting -> connected) Oct 13 22:25:26 tracker NetworkManager[333]: <warn> could not read ppp stats: No such device Oct 13 22:25:26 tracker pppd[1091]: Exit. Oct 13 22:25:26 tracker NetworkManager[333]: <info> Unmanaged Device found; state CONNECTED forced. (see http://bugs.launchpad.net/bugs/191889) Oct 13 22:25:26 tracker NetworkManager[333]: SCPlugin-Ifupdown: devices removed (path: /sys/devices/virtual/net/ppp0, iface: ppp0) Oct 13 22:25:26 tracker NetworkManager[333]: <info> disconnect failed: (32) The serial port is not open. Oct 13 22:25:27 tracker kernel: [12442.048218] ata1.00: configured for UDMA/100 Oct 13 22:25:27 tracker kernel: [12442.048241] ata1: EH complete Oct 13 22:25:27 tracker kernel: [12442.050941] ata1.00: exception Emask 0x0 SAct 0x0 SErr 0x0 action 0x6 Oct 13 22:25:27 tracker kernel: [12442.057483] ata1.00: BMDMA stat 0x66 Oct 13 22:25:27 tracker kernel: [12442.061153] ata1.00: failed command: WRITE DMA Oct 13 22:25:27 tracker kernel: [12442.065696] ata1.00: cmd ca/00:02:c4:fb:5b/00:00:00:00:00/e0 tag 0 dma 1024 out Oct 13 22:25:27 tracker kernel: [12442.065699] res 51/84:00:c4:fb:5b/00:00:00:00:00/e0 Emask 0x30 (host bus error) Oct 13 22:25:27 tracker kernel: [12442.081273] ata1.00: status: { DRDY ERR } Oct 13 22:25:27 tracker kernel: [12442.085366] ata1.00: error: { ICRC ABRT } Oct 13 22:25:27 tracker kernel: [12442.089488] ata1: soft resetting link Oct 13 22:25:27 tracker kernel: [12442.260206] ata1.00: configured for UDMA/100 Oct 13 22:25:27 tracker kernel: [12442.260226] ata1: EH complete Oct 13 22:25:27 tracker kernel: [12442.268296] ata1.00: exception Emask 0x0 SAct 0x0 SErr 0x0 action 0x6 Oct 13 22:25:27 tracker kernel: [12442.274829] ata1.00: BMDMA stat 0x66 Oct 13 22:25:27 tracker kernel: [12442.278480] ata1.00: failed command: WRITE DMA Oct 13 22:25:27 tracker kernel: [12442.283022] ata1.00: cmd ca/00:02:c4:fb:5b/00:00:00:00:00/e0 tag 0 dma 1024 out Oct 13 22:25:27 tracker kernel: [12442.283026] res 51/84:00:c4:fb:5b/00:00:00:00:00/e0 Emask 0x30 (host bus error) Oct 13 22:25:27 tracker kernel: [12442.298605] ata1.00: status: { DRDY ERR } Oct 13 22:25:27 tracker kernel: [12442.302693] ata1.00: error: { ICRC ABRT } Oct 13 22:25:27 tracker kernel: [12442.306763] ata1: soft resetting link Oct 13 22:25:27 tracker kernel: [12442.476225] ata1.00: configured for UDMA/100 Oct 13 22:25:27 tracker kernel: [12442.476248] ata1: EH complete Oct 13 22:25:29 tracker NetworkManager[333]: <info> Activation (ttyUSB1) starting connection 'cdma' Oct 13 22:25:29 tracker NetworkManager[333]: <info> (ttyUSB1): device state change: 3 -> 4 (reason 0) Oct 13 22:25:29 tracker NetworkManager[333]: <info> Unmanaged Device found; state CONNECTED forced. (see http://bugs.launchpad.net/bugs/191889) Oct 13 22:25:29 tracker NetworkManager[333]: <info> Activation (ttyUSB1) Stage 1 of 5 (Device Prepare) scheduled... Oct 13 22:25:29 tracker NetworkManager[333]: <info> Activation (ttyUSB1) Stage 1 of 5 (Device Prepare) started... Oct 13 22:25:29 tracker NetworkManager[333]: <info> Activation (ttyUSB1) Stage 1 of 5 (Device Prepare) complete. Oct 13 22:25:30 tracker modem-manager[337]: <info> Modem /org/freedesktop/ModemManager/Modems/0: state changed (connected -> registered) Oct 13 22:25:30 tracker modem-manager[337]: <info> Modem /org/freedesktop/ModemManager/Modems/0: state changed (registered -> connecting) Oct 13 22:25:30 tracker modem-manager[337]: <info> Modem /org/freedesktop/ModemManager/Modems/0: state changed (connecting -> registered) Oct 13 22:25:30 tracker NetworkManager[333]: <warn> CDMA connection failed: (32) Sending command failed: device is not enabled Oct 13 22:25:30 tracker NetworkManager[333]: <info> (ttyUSB1): device state change: 4 -> 9 (reason 0) Oct 13 22:25:30 tracker NetworkManager[333]: <info> Unmanaged Device found; state CONNECTED forced. (see http://bugs.launchpad.net/bugs/191889) Oct 13 22:25:30 tracker NetworkManager[333]: <info> Marking connection 'cdma' invalid. Oct 13 22:25:30 tracker NetworkManager[333]: <warn> Activation (ttyUSB1) failed. Oct 13 22:25:30 tracker NetworkManager[333]: <info> (ttyUSB1): device state change: 9 -> 3 (reason 0) Oct 13 22:25:30 tracker NetworkManager[333]: <info> (ttyUSB1): deactivating device (reason: 0). Oct 13 22:25:30 tracker NetworkManager[333]: <info> Unmanaged Device found; state CONNECTED forced. (see http://bugs.launchpad.net/bugs/191889)