diod: 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/sbin/diod - from package: diod

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

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