centos5.3,centos5.4安装webmin默认的是 mysql 5.0,php5.1 我需要升级到mysql5.1和php5.2(禁止php5.3)，怎么办？

给yum安装rpmforge：
http://wiki.centos.org/AdditionalResources/Repositories/RPMForge

yum list mysql php 发现都是最新版本了，看来标准的yum源没有更新

http://download.fedora.redhat.com/pub/epel/5/i386/ 这里有些可用的库源

wget http://download.fedora.redhat.com/pub/epel/5/i386/epel-release-5-4.noarch.rpm
wget http://rpms.famillecollet.com/el5.i386/remi-release-5-7.el5.remi.noarch.rpm
rpm -Uvh remi-release-5-7.el5.remi.noarch.rpm epel-release-5-*.noarch.rpm
yum --enablerepo=remi list mysql

发现可以升级到 mysql 5.1.44-1.el5.remi

yum --enablerepo=remi update mysql

发现需要把php也一并升级到 5.3，
而zend optimizer 目前不支持 Php5.3，于是需要禁止升级php5.3

vi /etc/yum.conf

最后一行增加

exclude=php*5.3*

然后再yum --enablerepo=remi update mysql，就看不到php的升级了

搞定：
[[email protected] backup]# php -v  还是旧的5.1.6
PHP 5.1.6 (cli) (built: Jan 13 2010 17:13:05)
Copyright (c) 1997-2006 The PHP Group
Zend Engine v2.1.0, Copyright (c) 1998-2006 Zend Technologies
    with Zend Extension Manager v1.2.2, Copyright (c) 2003-2007, by Zend Technologies
    with Zend Optimizer v3.3.3, Copyright (c) 1998-2007, by Zend Technologies
[[email protected] backup]# mysql -V  升级到5.1.44了
mysql  Ver 14.14 Distrib 5.1.44, for redhat-linux-gnu (i686) using readline 5.1

升級mysql 5.1.41-1之後,請執行下列動作:
(1)將原有的/etc/my.cnf備份,將/etc/my.cnf.rpmnew改 為my.cnf
(2)升級table
mysql_upgrade -p
(3)自動修復table
mysqlcheck --all-databases --check-upgrade --auto-repair -p

找到一个yum源，有php5.2，方法如下：
http://www.webtatic.com/blog/2009/06/php-530-on-centos-5/


rpm --import http://repo.webtatic.com/yum/RPM-GPG-KEY-webtatic-andy
wget -P /etc/yum.repos.d/ http://repo.webtatic.com/yum/webtatic.repo
yum --enablerepo=webtatic list php
发现有php5.2 和 php5.3可以升级，
OK，我们vi /etc/yum.conf 禁止升级php5.3
vi /etc/yum.conf
最后一行增加
exclude=php*5.3*

或者：
yum --enablerepo=webtatic --exclude=php*5.3* list php

yum --enablerepo=webtatic --exclude=php*5.3* update -y php

[[email protected] backup]# php -v  升级到5.2.12了，收工！
PHP 5.2.12 (cli) (built: Dec 17 2009 19:40:56)
Copyright (c) 1997-2009 The PHP Group
Zend Engine v2.2.0, Copyright (c) 1998-2009 Zend Technologies
    with Zend Extension Manager v1.2.2, Copyright (c) 2003-2007, by Zend Technologies
    with Zend Optimizer v3.3.3, Copyright (c) 1998-2007, by Zend Technologies


yum-allowdowngrade 可以降级的插件：

allow downgrade for yum:

yum install yum-allowdowngrade

Add a line to  yum.conf:

showdupesfromrepos=1

After that list all php packages:

yum list php

If php 5.2.8 is available, remove new one:

yum remove php

and install an old one:

yum --allow-downgrade install php-5.2.8
 

另一个yum升级php方法：

rpm --import http://www.jasonlitka.com/media/RPM-GPG-KEY-jlitka 
vi /etc/yum.repos.d/utterramblings.repo

[utterramblings]
name=Jason's Utter Ramblings Repo
baseurl=http://www.jasonlitka.com/media/EL$releasever/$basearch/
enabled=0
gpgcheck=1
gpgkey=http://www.jasonlitka.com/media/RPM-GPG-KEY-jlitka

yum --enablerepo=utterramblings --exclude=php*5.3* update -y php