I have encountered this issue for many times on OrangePi PC, this issue happened by using following version
Armbian version: 5.41, Kernel version: 4.14.32
Armbian version: 5.77, Kernel version: 4.19.25
Armbian version: 5.90, Kernel version: 4.19.57
I have more than 10 Orangepi PC running busy tasks at the same time, and this issue happened more than 15 times in the past year, still have no idea how to deal with this, it is still able to send data to my server somehow, which means that the internet connection is available, but i'm not able to ssh.
I have tried the following methods:
Wrote a udev file to copy all system log when usb pendrive is detected, this works fine when device runs normally, but not working when encounter this issue.
Using watchdog, works fine if using fork bomb to test, but not able to recover from this issue
Tried connect to a keyboard and hdmi monitor, this works fine when device runs normally, but not working when encounter this issue.
Using TTL serial to usb adapter, I'm able to control device when it runs normally, but not working when encounter this issue.
I found that dmesg record some error message as below when I encountered this again yesterday
Currently, I might try to continuously detect whether this error message occurred in dmesg, if yes, I will try using this command "sudo systemctl --force --force reboot"(it seems that /sbin/reboot does not work at the moment)