shinken-arbiter: 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/sbin/shinken-arbiter - from package: shinken-arbiter

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

On Debian possible default full paths are:

/usr/bin/shinken-arbiter - from package: shinken-common

You may install the required package with command apt-get install {package}

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