flashbench: 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/flashbench - from package: flashbench

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

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