fdm: 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/fdm - from package: fdm

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

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