drbl-doit: 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
/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/drbl-doit - from package: drbl

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