lunzip: 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

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/lunzip - from package: lunzip

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