nield: 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/sbin/nield - from package: nield

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