После установки memcached и указания кэширования вместо file на memory — в config.php
Notice: MemcachePool::get(): Server localhost (tcp 11211, udp 0) failed with: В соединении отказано (111) in /var/www/user/data/www/skize.ru/engine/lib/external/DklabCache/Zend/Cache/Backend/Memcached.php on line 134
Отправил тикет в тех.поддержку хостинга
Написали что проблема была исправлена:

У Вас не был запущен memcache:
root@skize:~# /etc/init.d/memcached status
[FAIL] memcached is not running… failed!

Посмотрел логи и обнаружил, что не была создана папка для socket'a:
failed to listen on UNIX socket: /var/run/memcached/memcached.sock: Invalid argument
bind(): No such file or directory
failed to listen on UNIX socket: /var/run/memcached/memcached.sock: Invalid argument

Создал папку и теперь сервис доступен:
root@skize:~# /etc/init.d/memcached status
[ ok ] memcached is running.

Дело в том, что ошибка в верху сайта:

Notice: MemcachePool::get(): Server localhost (tcp 11211, udp 0) failed with: В соединении отказано (111) in /var/www/user/data/www/skize.ru/engine/lib/external/DklabCache/Zend/Cache/Backend/Memcached.php on line 134

Всё равно появляется Помогите пожалуйста

Заранее — в etc/memcached.conf

# memcached default config file
# 2003 - Jay Bonci <jaybonci@debian.org>
# This configuration file is read by the start-memcached script provided as
# part of the Debian GNU/Linux distribution. 

# Run memcached as a daemon. This command is implied, and is not needed for the
# daemon to run. See the README.Debian that comes with this package for more
# information.
-d

# Log memcached's output to /var/log/memcached
logfile /var/log/memcached.log

# Be verbose
# -v

# Be even more verbose (print client commands as well)
# -vv

# Start with a cap of 64 megs of memory. It's reasonable, and the daemon default
# Note that the daemon will grow to this size, but does not start out holding this much
# memory
-m 350

# Default connection port is 11211
-p 11211 

# Run the daemon as root. The start-memcached will default to running as root if no
# -u command is present in this config file
-u root

# Specify which IP address to listen on. The default is to listen on all IP addresses
# This parameter is one of the only security measures that memcached has, so make sure
# it's listening on a firewalled interface.
-l 127.0.0.1

# Limit the number of simultaneous incoming connections. The daemon default is 1024
# -c 1024

# Lock down all paged memory. Consult with the README and homepage before you do this
# -k

# Return error when memory is exhausted (rather than removing items)
# -M

# Maximize core file limit
# -r

# Specify the maximum size permitted for storing an object within the memcached instance.
# -I 8m
# Unix socket path to listen on (disables network support).
-s /var/run/memcached.socket
# Permissions (in octal format) for Unix socket created with -s option.
-a 0777

Как решена была проблема:

Ошибка была в порте 11211 — попросил тех поддержку открыть данный порт для memcached — ошибка ушла