The xtrabackup binary actually exists as four separate binaries: xtrabackup, xtrabackup_51, xtrabackup_55 and xtrabackup_56. This is to ensure binary compatibility of InnoDB data files across releases. Which binary you should use depends on the version of the server that produced the data files you want to back up. It’s important to use the correct binary. Whichever binary is used to create a backup should also be the binary used to prepare that backup.
Throughout the documentation, whenever the xtrabackup binary is mentioned, it’s assumed that the name of the correct binary will be substituted. The following table summarizes which binary should be used with different server versions.
|MySQL 5.1.* with InnoDB plugin||xtrabackup|
|Percona Server 5.0||xtrabackup_51|
|Percona Server 5.1||xtrabackup|
|Percona Server 5.5||xtrabackup_55|
|Percona Server 5.6||xtrabackup_56|