mt-gnu: 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:

/bin/mt-gnu - from package: cpio

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

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