dcfldd: 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 CentOS possible default full paths are:

/usr/bin/dcfldd - from package: dcfldd

You may install the required package with command yum install {package}

On Debian possible default full paths are:

/usr/bin/dcfldd - from package: dcfldd

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

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