backup

#!/bin/sh
#
# backup

BACKUP_DIR='/mnt/backup'

if df | grep -q "${BACKUP_DIR}"; then
    # shellcheck disable=SC3009
    rsync -aAXHv --delete --exclude={"/dev/*","/proc/*","/sys/*","/tmp/*","/run/*","/mnt/*","/media/*","/lost+found"} / "$BACKUP_DIR"
else printf '%s\n' "${BACKUP_DIR} is not a mount point. Not backing up."
fi