glx-multi-context-ib-1: 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/glx-multi-context-ib-1 - from package: piglit

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

Error in other languages:
glx-multi-context-ib-1: bevel nie gevind nie
glx-multi-context-ib-1: comandă negăsită
glx-multi-context-ib-1: comando não encontrado
glx-multi-context-ib-1: commande introuvable
glx-multi-context-ib-1: command not found
glx-multi-context-ib-1: käsku ei ole
glx-multi-context-ib-1: không tìm thấy lệnh
glx-multi-context-ib-1: komanda nerasta
glx-multi-context-ib-1: Kommando nicht gefunden.
glx-multi-context-ib-1: kommandot finns inte
glx-multi-context-ib-1: komut yok
glx-multi-context-ib-1: nie znaleziono polecenia
glx-multi-context-ib-1: níor aimsíodh an t-ordú
glx-multi-context-ib-1: no se encontró la orden
glx-multi-context-ib-1: no s'ha trobat l'ordre
glx-multi-context-ib-1: opdracht niet gevonden
glx-multi-context-ib-1: parancs nem található
glx-multi-context-ib-1: perintah tidak ditemukan
glx-multi-context-ib-1: príkaz nenájdený
glx-multi-context-ib-1: příkaz nenalezen
glx-multi-context-ib-1: команда не найдена
glx-multi-context-ib-1: командата не е открита
glx-multi-context-ib-1: 命令找不到
glx-multi-context-ib-1: コマンドが見つかりません