lsdvd: 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/lsdvd - from package: lsdvd

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

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