storage_classes: 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/storage_classes - from package: ctn

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