The percona-release rpm and the whole Percona rpm package mechanism is suboptimal for standard CentOS 6 installtions.
- mysql-libs is automatically replaced by Percona-Server-shared-51, which leads to mysqldump and other stock-CentOS6 MySQL 5.1 tools to stop working
- /etc/my.cnf is automatically replaced by a default one, if you remove the Percona-Server-shared-51 rpm using “rpm -e --nodeps Percona-Server-shared-51”. You need to move /etc/my.cnf.rpmsave to /etc/my.cnf
- Why is the packaging of Percona harmful to the stock CentOS 6 packages? Other repositories like EPEL do not overwrite/replace standard packages. When, like in my case, you do NOT want to install the Percona MySQL Server, but only percona-toolkit or xtrabackup, you must explicitely include these packages in /etc/yum.repos.d/percona-release.repo, otherwise you hose your installation. If I want to install any Percona packages instead of the standard ones, I do so on intention.
So please remove the package aliases for the standard CentOS package names / categories, to avoid the sock packages to automatically beeing replaced by your stuff.