glsl-kwin-blur-2: 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/lib64/piglit/bin/glsl-kwin-blur-2 - from package: piglit

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

Error in other languages:
glsl-kwin-blur-2: bevel nie gevind nie
glsl-kwin-blur-2: comandă negăsită
glsl-kwin-blur-2: comando não encontrado
glsl-kwin-blur-2: commande introuvable
glsl-kwin-blur-2: command not found
glsl-kwin-blur-2: käsku ei ole
glsl-kwin-blur-2: không tìm thấy lệnh
glsl-kwin-blur-2: komanda nerasta
glsl-kwin-blur-2: Kommando nicht gefunden.
glsl-kwin-blur-2: kommandot finns inte
glsl-kwin-blur-2: komut yok
glsl-kwin-blur-2: nie znaleziono polecenia
glsl-kwin-blur-2: níor aimsíodh an t-ordú
glsl-kwin-blur-2: no se encontró la orden
glsl-kwin-blur-2: no s'ha trobat l'ordre
glsl-kwin-blur-2: opdracht niet gevonden
glsl-kwin-blur-2: parancs nem található
glsl-kwin-blur-2: perintah tidak ditemukan
glsl-kwin-blur-2: príkaz nenájdený
glsl-kwin-blur-2: příkaz nenalezen
glsl-kwin-blur-2: команда не найдена
glsl-kwin-blur-2: командата не е открита
glsl-kwin-blur-2: 命令找不到
glsl-kwin-blur-2: コマンドが見つかりません