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.