t3chnaztea/batocera-skills/batocera-maintenance

Batocera Maintenance

Keeping the cabinet healthy: running things at boot and on a schedule, backing up what matters, and surviving version upgrades. Assumes the connection pattern and filesystem model from batocera-ops.

There is no crond — use a boot service

Batocera does not run a general-purpose crond. Don't write a crontab and assume it fires; it won't. The mechanism for "run this at boot / on a schedule" is a boot service.

Since v43, the entry point is /userdata/system/services/custom_service (it replaced /userdata/system/custom.sh; the upgrade auto-converts an existing custom.sh). A service is a script Batocera runs at boot with a start argument. Enable/inspect services:

SSHB "batocera-services list"
SSHB "cat /userdata/system/services/custom_service"

Scheduling without cron: the boot-loop pattern

To run something periodically, the service launches a background loop that sleeps and re-checks. This is how the cabinet does hourly/daily/monthly work with no cron:

# inside custom_service, on the 'start' case:
(
  while true; do
    # hourly re-assert (e.g. CPU governor; see batocera-tuning)
    /etc/init.d/S18governor start 2>/dev/null
 
    # once-a-day / once-a-month gating: compare a stamp file to `date`
    stamp=/userdata/system/.last-monthly-backup
    if [ "$(cat "$stamp" 2>/dev/null)" != "$(date +%Y-%m)" ]; then
      /userdata/system/tools/backup-to-remote.sh && date +%Y-%m > "$stamp"
    fi
 
    sleep 3600
  done
) &

Key ideas:

• Catch-up, not clock-exact. Gate on "has this period's job run yet?"

(compare a stamp to date +%Y-%m or %Y-%m-%d), not on "is it exactly 3 AM?". A cabinet that's powered off at 3 AM would never run a clock-exact job; the stamp approach runs it on the first boot of the new period instead.

• Idempotent body. The loop may re-enter; the gated job must be safe to skip

when already done this period.

• Don't park schedulable scripts in `/userdata/system/scripts/` — ES invokes

executables there as game event hooks (see batocera-ops → emulationstation). Put tools in /userdata/system/tools/ or similar and call them from the service.

After editing custom_service, back it up first and test the loop logic before relying on it (run the gated command by hand once).

Backups

The doctrine: push-only, dry-run-first, over SSH. The cabinet pushes a copy of the important parts of /userdata to another machine; you always dry-run an rsync before letting it delete anything. Architecture, what to include/exclude, and the catch-up schedule are in references/backup.md.

Back up before every upgrade. A major-version upgrade is the highest-risk routine event; a fresh backup of saves/system/bios (and ideally decorations/ shaders/themes) is the difference between a 10-minute rollback and a rebuild.

Version upgrades

Major Batocera upgrades rename ROM directories, change the boot-service model, and swap emulators — each of which silently breaks things if you don't migrate. The v42→v43 migration (representative of the class) with the full rename table and a post-upgrade checklist is in references/v42-to-v43.md. The short doctrine:

1. Full backup first (above).
2. Upgrade.
3. Walk the post-upgrade checklist: move content out of renamed/stub dirs,

migrate moved saves, confirm the boot service converted, and re-check the CPU governor (a v43 build can boot stuck in powersave — see batocera-tuning).

1. Verify a game from each major system actually launches before calling it done.