vdr: 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/bin/vdr - from package: vdr

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