rage4.rb: 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/lib/ruby/vendor_ruby/fog/bin/rage4.rb - from package: ruby-fog

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

Error in other languages:
rage4.rb: bevel nie gevind nie
rage4.rb: comandă negăsită
rage4.rb: comando não encontrado
rage4.rb: commande introuvable
rage4.rb: command not found
rage4.rb: käsku ei ole
rage4.rb: không tìm thấy lệnh
rage4.rb: komanda nerasta
rage4.rb: Kommando nicht gefunden.
rage4.rb: kommandot finns inte
rage4.rb: komut yok
rage4.rb: nie znaleziono polecenia
rage4.rb: níor aimsíodh an t-ordú
rage4.rb: no se encontró la orden
rage4.rb: no s'ha trobat l'ordre
rage4.rb: opdracht niet gevonden
rage4.rb: parancs nem található
rage4.rb: perintah tidak ditemukan
rage4.rb: príkaz nenájdený
rage4.rb: příkaz nenalezen
rage4.rb: команда не найдена
rage4.rb: командата не е открита
rage4.rb: 命令找不到
rage4.rb: コマンドが見つかりません