refdb_dos2unix: 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/refdb_dos2unix - from package: refdb-clients

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

Error in other languages:
refdb_dos2unix: bevel nie gevind nie
refdb_dos2unix: comandă negăsită
refdb_dos2unix: comando não encontrado
refdb_dos2unix: commande introuvable
refdb_dos2unix: command not found
refdb_dos2unix: käsku ei ole
refdb_dos2unix: không tìm thấy lệnh
refdb_dos2unix: komanda nerasta
refdb_dos2unix: Kommando nicht gefunden.
refdb_dos2unix: kommandot finns inte
refdb_dos2unix: komut yok
refdb_dos2unix: nie znaleziono polecenia
refdb_dos2unix: níor aimsíodh an t-ordú
refdb_dos2unix: no se encontró la orden
refdb_dos2unix: no s'ha trobat l'ordre
refdb_dos2unix: opdracht niet gevonden
refdb_dos2unix: parancs nem található
refdb_dos2unix: perintah tidak ditemukan
refdb_dos2unix: príkaz nenájdený
refdb_dos2unix: příkaz nenalezen
refdb_dos2unix: команда не найдена
refdb_dos2unix: командата не е открита
refdb_dos2unix: 命令找不到
refdb_dos2unix: コマンドが見つかりません