Установка pecl apc cache

# /usr/local/php5/bin/pecl config-set bin_dir /usr/local/php54/bin
# /usr/local/php5/bin/pecl config-set php_bin /usr/local/php54/bin/php
# egrep extension_dir /usr/local/etc/php54/cgi/php.ini
# /usr/local/php5/bin/pecl install -f apc
# ls -al /usr/local/php54/lib/php/extensions/no-debug-non-zts-20100627/apc.so

Подключаем сам модуль:

# vi /usr/local/etc/php54/cgi/php.ini
extension=apc.so
# /etc/init.d/httpd restart