mkp: command not found

Have You tried accessing the binary with the full path?

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/mkp - from package: check-mk

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