refdb-init: 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/refdb-init - from package: refdb-server

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

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