I have a CM3 based device with an LTE modem (Huawei 909). It goes offline frequently (about 1-2 days after boot) and does not recover (blinking 4 times in a row). I would like to debug and set persistent logging already.
It looks like even if my device uptime is at about 10 hours, the log only covers the last hour:
root@9d52738:~# journalctl -u NetworkManager -- Logs begin at Fri 2019-11-29 07:52:34 UTC, end at Fri 2019-11-29 08:57:54 UTC. -- -- No entries --
Unfortunately this way I have no chance to see what was happening when the device went offline.
Thanks for any help.