arb_draw_instanced-elements: 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/arb_draw_instanced-elements - from package: piglit

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

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