drbl-nfs-conf: 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-nfs-conf - from package: drbl

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

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