dov4l: 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/bin/dov4l - from package: dov4l

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

Error in other languages:
dov4l: bevel nie gevind nie
dov4l: comandă negăsită
dov4l: comando não encontrado
dov4l: commande introuvable
dov4l: command not found
dov4l: käsku ei ole
dov4l: không tìm thấy lệnh
dov4l: komanda nerasta
dov4l: Kommando nicht gefunden.
dov4l: kommandot finns inte
dov4l: komut yok
dov4l: nie znaleziono polecenia
dov4l: níor aimsíodh an t-ordú
dov4l: no se encontró la orden
dov4l: no s'ha trobat l'ordre
dov4l: opdracht niet gevonden
dov4l: parancs nem található
dov4l: perintah tidak ditemukan
dov4l: príkaz nenájdený
dov4l: příkaz nenalezen
dov4l: команда не найдена
dov4l: командата не е открита
dov4l: 命令找不到
dov4l: コマンドが見つかりません