really: 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/sbin/really - from package: chiark-really

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

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