Get mysql to start automatically on startup

I realize that there are many questions around here to answer that problem - but none seems to work for me so far.

I attempted:

sudo update-rc.d mysql defaults

This resulted in a locale error, which I fixed with How do I fix my locale issue? by altering /etc/environment

LC_ALL=en_US.UTF-8
LANG=en_US.UTF-8

Now, by trying update-rc.d again, I get:

update-rc.d: warning: /etc/init.d/mysql missing LSB information
update-rc.d: see <http://wiki.debian.org/LSBInitScripts>
 System start/stop links for /etc/init.d/mysql already exist.

I found a suggestion on http://ubuntuforums.org/showthread.php?t=1313898 to use:

user@computer:/etc/init.d$ sudo update-rc.d -f mystartupscript remove
user@computer:/etc/init.d$ sudo update-rc.d mystartupscript defaults
user@computer:/etc/init.d$ sudo chmod +x ./mystartupscript

But do I risk to break my mysql implementation here? It's on a production server, so I can't just try it out and then suddenly be unable to start up mysql again.

In the end, the mysql server needs to run on startup. We had a few server restarts coming from the host, and everytime when that's the case, the database is not started and the hosted pages remain down until mysql is started manually.

Edit: /etc/init.d/mysql contents

#!/bin/sh -e
# upstart-job
#
# Symlink target for initscripts that have been converted to Upstart.

set -e

INITSCRIPT="$(basename "$0")"
JOB="${INITSCRIPT%.sh}"

if [ "$JOB" = "upstart-job" ]; then
    if [ -z "$1" ]; then
        echo "Usage: upstart-job JOB COMMAND" 1>&2
        exit 1
    fi

    JOB="$1"
    INITSCRIPT="$1"
    shift
else
    if [ -z "$1" ]; then
        echo "Usage: $0 COMMAND" 1>&2
        exit 1
    fi
fi

COMMAND="$1"
shift


if [ -z "$DPKG_MAINTSCRIPT_PACKAGE" ]; then
        ECHO=echo
else
        ECHO=:
fi

$ECHO "Rather than invoking init scripts through /etc/init.d, use the service(8)"
$ECHO "utility, e.g. service $INITSCRIPT $COMMAND"

# Only check if jobs are disabled if the currently _running_ version of
# Upstart (which may be older than the latest _installed_ version)
# supports such a query.
#
# This check is necessary to handle the scenario when upgrading from a
# release without the 'show-config' command (introduced in
# Upstart for Ubuntu version 0.9.7) since without this check, all
# installed packages with associated Upstart jobs would be considered
# disabled.
#
# Once Upstart can maintain state on re-exec, this change can be
# dropped (since the currently running version of Upstart will always
# match the latest installed version).

UPSTART_VERSION_RUNNING=$(initctl version|awk '{print $3}'|tr -d ')')

if dpkg --compare-versions "$UPSTART_VERSION_RUNNING" ge 0.9.7
then
    initctl show-config -e "$JOB"|grep -q '^  start on' || DISABLED=1
fi

case $COMMAND in
status)
    $ECHO
    $ECHO "Since the script you are attempting to invoke has been converted to an"
    $ECHO "Upstart job, you may also use the $COMMAND(8) utility, e.g. $COMMAND $JOB"
    $COMMAND "$JOB"
    ;;
start|stop)
    $ECHO
    $ECHO "Since the script you are attempting to invoke has been converted to an"
    $ECHO "Upstart job, you may also use the $COMMAND(8) utility, e.g. $COMMAND $JOB"
    if status "$JOB" 2>/dev/null | grep -q ' start/'; then
        RUNNING=1
    fi
    if [ -z "$RUNNING" ] && [ "$COMMAND" = "stop" ]; then
        exit 0
    elif [ -n "$RUNNING" ] && [ "$COMMAND" = "start" ]; then
        exit 0
    elif [ -n "$DISABLED" ] && [ "$COMMAND" = "start" ]; then
        exit 0
    fi
    $COMMAND "$JOB"
    ;;
restart)
    $ECHO
    $ECHO "Since the script you are attempting to invoke has been converted to an"
    $ECHO "Upstart job, you may also use the stop(8) and then start(8) utilities,"
    $ECHO "e.g. stop $JOB ; start $JOB. The restart(8) utility is also available."
    if status "$JOB" 2>/dev/null | grep -q ' start/'; then
        RUNNING=1
    fi
    if [ -n "$RUNNING" ] ; then
        stop "$JOB"
    fi
    # If the job is disabled and is not currently running, the job is
    # not restarted. However, if the job is disabled but has been forced into the
    # running state, we *do* stop and restart it since this is expected behaviour
    # for the admin who forced the start.
    if [ -n "$DISABLED" ] && [ -z "$RUNNING" ]; then
        exit 0
    fi
    start "$JOB"
    ;;
reload|force-reload)
    $ECHO
    $ECHO "Since the script you are attempting to invoke has been converted to an"
    $ECHO "Upstart job, you may also use the reload(8) utility, e.g. reload $JOB"
    reload "$JOB"
    ;;
*)
    $ECHO
    $ECHO "The script you are attempting to invoke has been converted to an Upstart" 1>&2
    $ECHO "job, but $COMMAND is not supported for Upstart jobs." 1>&2
    exit 1
esac