Unraid user script to create backups of the flash drive and appdata on a schedule. An email is sent with the full command output if the cronjob fails.

backup_flash_and_appdata.sh

#!/bin/bash
#name=Backup flash and appdata
#description=Creates tarballs of the flash drive and appdata share.
#argumentDescription=Backup directory
#argumentDefault=/mnt/user/Backup/Sovngarde
#arrayStarted=true
#noParity=true
#clearLog=true
set -eo pipefail
shopt -s extglob

PATH="/usr/local/emhttp/webGui/scripts:$PATH"
cd "${1:-/mnt/user/Backup/Sovngarde}"

create_backup() {
  # Usage: create_backup <name> <src>
  local name=$1
  local src=$2
  local date; date=$(date -I)
  local tarball="${name}_${date}.tgz"

  echo "$src -> $tarball"

  tar cvfz "$tarball" \
    --exclude-ignore .tarignore \
    --transform "s/^\./${name}/" \
    --show-stored-names \
    --totals \
    -C "$src" .

  # Remove old backups
  rm -fv "$name"_!("$date").tgz
}

run() {
  echo "Backing up to $(pwd)"
  create_backup flash /boot
  create_backup appdata /mnt/user/appdata

  # For testing error notification
  if [[ $FAIL_ON_PURPOSE ]]; then
    echo 'Task failed successfully.' >&2
    return 1
  fi
}

# Capture log for error report while still writing to stdout
# https://stackoverflow.com/a/16292136
{ log=$(run 2>&1 | tee /dev/fd/5); } 5>&1 || err=$?
if (( err > 0 )); then
  notify \
    -s "$(sed -n 's/^#name=//p' "${BASH_SOURCE[0]}") script failed" \
    -d "Exit code $err (logs below)" \
    -i 'alert' \
    -m "$log"
fi