refdbd: 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/refdbd - from package: refdb-server

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

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