mk-log-player: command not found

Maybe Your $PATH variable doesn't contain the default paths? echo $PATH should give something like:

[root@server ~]# echo $PATH
/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin

If it's empty, You may set the PATH variable with this command

export PATH="/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin"

On CentOS possible default full paths are:

/usr/bin/mk-log-player - from package: maatkit

You may install the required package with command yum install {package}

Error in other languages:
mk-log-player: bevel nie gevind nie
mk-log-player: comandă negăsită
mk-log-player: comando não encontrado
mk-log-player: commande introuvable
mk-log-player: command not found
mk-log-player: käsku ei ole
mk-log-player: không tìm thấy lệnh
mk-log-player: komanda nerasta
mk-log-player: Kommando nicht gefunden.
mk-log-player: kommandot finns inte
mk-log-player: komut yok
mk-log-player: nie znaleziono polecenia
mk-log-player: níor aimsíodh an t-ordú
mk-log-player: no se encontró la orden
mk-log-player: no s'ha trobat l'ordre
mk-log-player: opdracht niet gevonden
mk-log-player: parancs nem található
mk-log-player: perintah tidak ditemukan
mk-log-player: príkaz nenájdený
mk-log-player: příkaz nenalezen
mk-log-player: команда не найдена
mk-log-player: командата не е открита
mk-log-player: 命令找不到
mk-log-player: コマンドが見つかりません