App Note : "Motion"

FYI

I use 'motion' on a few units - primarily a BeeLink
box.

Alas that box kept malfunctioning after awhile.
Re-installed a couple of times (DID use MX utils
to make a custom ISO of a working version as
a cheat, the thumb drive is taped to the unit).

Checking, the system disk was TOTALLY full. The
box couldn't boot properly - hung on a black
terminal-like screen - and could not update
giving a message about /var/cache/apt being
too full.

Managed to get the thing to boot to a raw
terminal by 'e'diting the grub menu item
and adding a '4' to the main line. This
gives you a terminal with networking.
'3' is a terminal with no networking.

'df' revealed that the entire main disk
was used up. Zero free space.

Using 'du' with appropriate params narrowed the
issue down to /var and eventually /var/lib/motion.

THE PROBLEM ... I'd forgotten to set 'movie_output'
to off in /etc/motion/motion.conf.

This saved movies to /var/lib/motion ... until
the whole disk was packed full. Apparently 'motion'
can't, or not obviously can't, regulate its own
disk usage there.

Fix :

Cleared all movies from /var/lib/motion.

This cleaned up the disk very nicely.

In /etc/motion/motion.conf I edited and
set "movie_output" to 'off'.

For fun I set the movie output default dir
to /dev/null too.

This SHOULD prevent future issues.

I made/had another app that makes low-speed
movies - using the 'stream' produced by
'motion' using OpenCV2 routines. Those are
relatively small and go where I want them
to go - and I have a "too old" function in
the app so only a few days worth are allowed
to exist.

Additional note for BeeLink boxes ... the
initial weird messages suggested an ACPI
error, LOTS of such messages. Tried to set
'acpi=off' both by editing the initial grub
entry AND in /etc/default/grub ... in both
cases this caused lock-up errors, something
about 16 and int0. Apparently you CAN'T turn
off ACPI on these things.

IF you want 'motion' to make/save movies for
you then you kinda HAVE to make a 'too-old'
daemon to auto-trim the specified directory.

(latest MX Linux, non-systemd incarnation)