drbl-get-nfsserver: 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

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/bin/drbl-get-nfsserver - from package: drbl

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