drbl-etc-hosts: 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/share/drbl/sbin/drbl-etc-hosts - from package: drbl

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

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