intel_gtt: 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/intel_gtt - from package: intel-gpu-tools

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

On Debian possible default full paths are:

/usr/bin/intel_gtt - from package: intel-gpu-tools

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

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