pos-array: command not found

Have You tried accessing the binary with the full path?

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/pos-array - from package: piglit

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