ngetty: 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:

/sbin/ngetty - from package: ngetty

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

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