fusioninventory-wakeonlan: 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 Debian possible default full paths are:

/usr/bin/fusioninventory-wakeonlan - from package: fusioninventory-agent

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

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