I have a router with an embedded 4G modem, a ZBT-WE826, running a customized build based on 18.06.7 (r7976). It's been solid for the past two years but today it's having some issues. The router is working and responsive but operations on the JFFS2 filesystem are all hanging in device wait (process status: D).
The problem is the router is about 2 hours away from where I am. I have working ssh access but I can't get it to reboot from the command line, because the reboot command is also stuck in device wait:
PID USER VSZ STAT COMMAND 12063 root 1200 D reboot
Is there any way to force a reboot under these circumstances, short of driving there and physically resetting it?