nandwrite: 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/nandwrite - from package: mtd-utils

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

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