I might have some ideas about what could be going on. Posted this over at the Neon OS Matrix channels but will do it here as well for your information.
Journald by default is configured to automatically write either to memory or disk. This is done by the “Storage=auto” setting within journald.conf
https://www.freedesktop.org/software/systemd/man/journald.conf.html
There are a few options. Volatile, Persistent and Auto.
- volatile means writing to /run/log/journal which is mounted as tmpfs into memory
- persistant means writing to /var/log/journal which most of the time is just a folder on disk.
- auto means writing to /run however as soon as systemd has all things mounted and /var becomes available switch over to that location.
I believe Dinkum is running quite some systemd services that are all configured to output to journald. As mycroft is rather verbal on logging, especially when running the default DEBUG log setting, that are enormous writes to disk. If it then also writes to EXt4 with journalling it even has a write multiplication of 4x - 6x.
Writing all these log lines continuously to disk if not configured correctly is killing embedded storage devices. There are more of these disk killers out there, like for instance fake-hwclock. This writes the time every few seconds to a file such that when the rpi reboots and as it doesn’t have a real time clock, it can grab the time from that file preventing it to be thrown back into 1900.
Combining this with a USB disk that has a long time bug of completely shutting down when to much bad blocks are detected.
This could be the cause of these devices just going black after a period of time.
Anyhow, perhaps you should just leave a Mark2 running on your desk and run IO tools in a shell to see how active the disk IO is. Especially the writing to disk.