drbl-fuh: 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/drbl-fuh - from package: drbl

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

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