drbl-userdel-file: 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-userdel-file - from package: drbl

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

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