mkdfiff: 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/mkdfiff - from package: directfb

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

On Debian possible default full paths are:

/usr/bin/mkdfiff - from package: libdirectfb-bin

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

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