#!/sbin/runscript
# $Header: /var/cvsroot/gentoo-x86/net-misc/memcached/files/1.3.3/init,v 1.1 2009/05/26 00:03:09 robbat2 Exp $

CONF="${SVCNAME#*.}"
CONFBASE="/etc/conf.d/memcached"

[ -z "${PIDBASE}" ] && PIDBASE="/var/run/memcached/memcached"
[ "${CONF}" == "memcached" ] && CONF=''

if [ -n "${CONF}" ]; then
        PIDFILE="${PIDBASE}-${PORT}.${CONF}.pid"
        CONFSRC="${CONFBASE}.${CONF}"
        if [ -f "${CONFSRC}" ]; then
         source "${CONFSRC}"
        else
         eerror "The configuration file $CONFSRC was not found!"
        fi
else
        PIDFILE="${PIDBASE}-${PORT}.pid"
        CONFSRC="${CONFBASE}"
fi

depend() {
        need net
		# per bug #269022, accurate time is important for memcached!
		# We include the full list of ways it might be set on boot.
		after ntp-client ntpd rdate openrdate adjtimex hwclock
}

checkconfig() {
        if [ -z "${LISTENON}" ]; then
          ewarn "You should edit $CONFSRC and specify an address to listen on."
          ewarn "Listening on any address (check your firewall!)"
        fi

}

start() {
        if [ -n "${CONF}" ]; then
                ebegin "Starting memcached (${CONF})"
        else
                ebegin "Starting memcached"
        fi
        checkconfig
        local dir="$(dirname ${PIDFILE})"
        if [ ! -d "${dir}" ]; then
          einfo " Creating ${dir}"
          mkdir -p "${dir}"
        fi
        chown ${MEMCACHED_RUNAS} "${dir}"
        if [ -f "${PIDFILE}" ]; then
          einfo "  Removing stale pidfile ${PIDFILE}"
          rm -f "${PIDFILE}" 1>/dev/null
        fi

        if [ -z "${LISTENON}" ]; then
          c_LISTENON=""
        else
          c_LISTENON="-l ${LISTENON}"
        fi

        /sbin/start-stop-daemon --start --pidfile "${PIDFILE}" \
                --exec "${MEMCACHED_BINARY}" \
				--startas "${MEMCACHED_BINARY}" -- \
                -d -p ${PORT} -U ${UDPPORT} ${c_LISTENON} -m ${MEMUSAGE} \
                -c ${MAXCONN} -u ${MEMCACHED_RUNAS} -P "${PIDFILE}" \
				${MISC_OPTS}
        eend $?
}

stop() {
        if [ -n "${CONF}" ]; then
                ebegin "Stopping memcached (${CONF})"
        else
                ebegin "Stopping memcached"
        fi
        start-stop-daemon --stop --quiet --pidfile "${PIDFILE}"
        rm -f "${PIDFILE}"
        eend $?
}

Ну и выполни команду:

rc-update add memcached default

и он будет в автозагрузке висеть всегда.
в etc/conf.d
создай файлик memcached:

# Copyright 2003 Gentoo Technologies, Inc
# $Header: /var/cvsroot/gentoo-x86/net-misc/memcached/files/1.3.3/conf,v 1.1 2009/05/26 00:03:09 robbat2 Exp $
# memcached config file

MEMCACHED_BINARY="/usr/bin/memcached"

#Specify memory usage in megabytes (do not use letters)
#64MB is default
MEMUSAGE="64"

#User to run as
MEMCACHED_RUNAS="memcached"

#Specify maximum number of concurrent connections
#1024 is default
MAXCONN="1024"

#Listen for connections on what address?
# If this is empty, memcached will listen on 0.0.0.0
# be sure you have a firewall in place!
LISTENON=""

#Listen for connections on what port?
PORT="11211"

# Listen for UDP connecitons on what port? 0 means turn off UDP
UDPPORT="${PORT}"

#PID file location
# '-${PORT}.${CONF}.pid' will be appended to this!
# You do not normally need to change this.
PIDBASE="/var/run/memcached/memcached"

#Other Options
MISC_OPTS=""

просто не помню он по дефолту там появляеться или я сам его создавал

А так memcachedb это и есть memcache или memcache(d)
Точнее memcachedb это база сама эта в оперативной памяти хранилище а вот, memcache и memcached это как бы драйвера для работы с ней.
Тоже самое что есть MYSQL база и драйверы для работы с ней mysql, mysqli, pdo и тд.
Понял?

Да, примерно понятно, спасибо!
Буду пробовать.