1) PHP に関して

# yum install -y php-mysql php-mbstring

2) /etc/php.ini の修正

# vi /etc/php.ini

内容

; PHP's default character set is set to empty.
; http://www.php.net/manual/en/ini.core.php#ini.default-charset
;default_charset = "iso-8859-1"
default_charset = EUC-JP

[mbstring]
; language for internal character representation.
; http://www.php.net/manual/en/mbstring.configuration.php#ini.mbstring.language
mbstring.language = Japanese

; internal/script encoding.
; Some encoding cannot work as internal encoding.
; (e.g. SJIS, BIG5, ISO-2022-*)
; http://www.php.net/manual/en/mbstring.configuration.php#ini.mbstring.internal-encoding
mbstring.internal_encoding = EUC-JP
;mbstring.internal_encoding = UTF-8

; http input encoding.
; http://www.php.net/manual/en/mbstring.configuration.php#ini.mbstring.http-input
mbstring.http_input = auto

; http output encoding. mb_output_handler must be
; registered as output buffer to function
; http://www.php.net/manual/en/mbstring.configuration.php#ini.mbstring.http-output
;mbstring.http_output = SJIS
mbstring.http_output = pass

; enable automatic encoding translation according to
; mbstring.internal_encoding setting. Input chars are
; converted to internal encoding by setting this to On.
; Note: Do _not_ use automatic encoding translation for
;       portable libs/applications.
; http://www.php.net/manual/en/mbstring.configuration.php#ini.mbstring.encoding-translation
;mbstring.encoding_translation = Off
mbstring.encoding_translation = On

; automatic encoding detection order.
; auto means
; http://www.php.net/manual/en/mbstring.configuration.php#ini.mbstring.detect-order
mbstring.detect_order = auto

; substitute_character used when character cannot be converted
; one from another
; http://www.php.net/manual/en/mbstring.configuration.php#ini.mbstring.substitute-character
mbstring.substitute_character = none;

2) /etc/my.cnf

# vi /etc/my.cnf

内容

[mysqld]
datadir=/var/lib/mysql
socket=/var/lib/mysql/mysql.sock
user=mysql
# Disabling symbolic-links is recommended to prevent assorted security risks
symbolic-links=0
# for EUCJP
default-character-set = ujis

[mysqld_safe]
log-error=/var/log/mysqld.log
pid-file=/var/run/mysqld/mysqld.pid

[client]
password=
# for EUCJP
default-character-set = ujis

[mysqldump]
# for EUCJP
default-character-set = ujis

3) データベース作成時
パスワードを指定してない場合は mysqld のみ

# mysqld -p -u root

mysql> create database XoopsKEC character set ujis;
mysql> exit

4) サービス再起動

# service mysqld restart
# service httpd restart

5) コピー

# chown -R apache:apache html/*
# chown -R apache:apache xoops_trust_path
# cp html/* /var/www/html/
# cp xoops_trust_path /var/www/

注意
HDE Controller では、 apache:apache が apache:root で、
/var/www が /home/lcvirtualdomain/ドメイン名 となります。
/home/lcvirtualdomain/ドメイン名/htdocs の所有者も apache:root にしておいたほうがインストーラーが権限を設定できます。

謝意：
http://d.hatena.ne.jp/iww/20090911/ujis
http://xoopscube.jp/forum/comment/17643