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Showing posts from April, 2020

Embedded Linux won't reboot - how to fix and repair

I have a lot of embedded systems running in our lab or in my home, all of them either as Raspberries or selfmade PCB with Yocto. Sometimes I can't reboot some systems, I think its the journald which causes some issues with SSD Cards, the error-message usually is:
Failed to open /dev/initctl

Anyhow, if you have this issue - a reboot can be force-forced:
systemctl --force --force reboot

Since a forced reboot does not sync the journal, the system typically comes up with a damaged FS. The remote fsck can be initiated by extending the command above with

sudo tune2fs -i 1m /dev/DISK && touch /forcefsck && systemctl --force --force reboot

(assumed you have access to a shell, via SSH or local access). When all goes fine, the system comes up with a clean FS. All this fuss comes from the SSD r/w actions, a well designed IoT embedded devices should have a flash mem part for the running OS.