服务器信息:
[mvj3@sdk2 ~]$ cat /proc/version
Linux version 2.6.18-194.el5 (mockbuild@ca-build10.us.oracle.com) (gcc
version 4.1.2 20080704 (Red Hat 4.1.2-48)) #1 SMP Mon Mar 29 22:10:29
EDT 2010

出错信息：
[mvj3@sdk2 ~]$ sudo yum install gettext-devel httpd-devel openssl-devel
zlib-devel gcc gcc-c++ curl-devel expat-devel gettext-devel mysql-server
mysql-devel libevent-devel mysql-devel mysql pcre pcre-devel
libxml2-devel sqlite-devel ruby-devel -y
Loaded plugins: security
Error: requested datatype primary not available
[mvj3@sdk2 ~]$ sudo yum upgrade
Loaded plugins: security
Error: requested datatype primary not available

解决方案：
[mvj3@sdk2 ~]$ sudo yum clean all
Loaded plugins: security
Cleaning up Everything
[mvj3@sdk2 ~]$ sudo rpm --rebuilddb