refdba: 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/bin/refdba - from package: refdb-clients

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

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