Rubens, deu isso:

root@server [/tmp]# rm -rf *
root@server [/tmp]# yum install mysql*
Loaded plugins: fastestmirror
Loading mirror speeds from cached hostfile
 * base: mirror.highspeedweb.net
 * centosplus: ftp.usf.edu
 * epel: serverbeach1.fedoraproject.org
 * extras: mirror.metrocast.net
 * rpmforge: apt.sw.be
 * updates: centos.omnispring.com
Excluding Packages in global exclude list
Finished
Excluding Packages from CentOS-5 - Base
Finished
Reducing CentOS-5 - Plus to included packages only
Finished
Excluding Packages from CentOS-5 - Updates
Finished
Setting up Install Process
No package mysql* available.
  * Maybe you meant: MySQL-devel, MySQL-client, MySQL-server, MySQL-test,
                   : MySQL-shared, MySQL-zrm
Nothing to do