dfu-suffix: 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/dfu-suffix - from package: dfu-util

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

On Debian possible default full paths are:

/usr/bin/dfu-suffix - from package: dfu-util

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

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