device2grub: 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 Debian possible default full paths are:

/usr/bin/device2grub - from package: fai-client

You may install the required package with command apt-get install {package}
Error in other languages:
device2grub: bevel nie gevind nie
device2grub: comandă negăsită
device2grub: comando não encontrado
device2grub: commande introuvable
device2grub: command not found
device2grub: käsku ei ole
device2grub: không tìm thấy lệnh
device2grub: komanda nerasta
device2grub: Kommando nicht gefunden.
device2grub: kommandot finns inte
device2grub: komut yok
device2grub: nie znaleziono polecenia
device2grub: níor aimsíodh an t-ordú
device2grub: no se encontró la orden
device2grub: no s'ha trobat l'ordre
device2grub: opdracht niet gevonden
device2grub: parancs nem található
device2grub: perintah tidak ditemukan
device2grub: príkaz nenájdený
device2grub: příkaz nenalezen
device2grub: команда не найдена
device2grub: командата не е открита
device2grub: 命令找不到
device2grub: コマンドが見つかりません