copybuffersubdata: 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/copybuffersubdata - from package: piglit

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

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