nvdump: 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/nvdump - from package: nvtv

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

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