fdo28551: 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/fdo28551 - from package: piglit

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

Error in other languages:
fdo28551: bevel nie gevind nie
fdo28551: comandă negăsită
fdo28551: comando não encontrado
fdo28551: commande introuvable
fdo28551: command not found
fdo28551: käsku ei ole
fdo28551: không tìm thấy lệnh
fdo28551: komanda nerasta
fdo28551: Kommando nicht gefunden.
fdo28551: kommandot finns inte
fdo28551: komut yok
fdo28551: nie znaleziono polecenia
fdo28551: níor aimsíodh an t-ordú
fdo28551: no se encontró la orden
fdo28551: no s'ha trobat l'ordre
fdo28551: opdracht niet gevonden
fdo28551: parancs nem található
fdo28551: perintah tidak ditemukan
fdo28551: príkaz nenájdený
fdo28551: příkaz nenalezen
fdo28551: команда не найдена
fdo28551: командата не е открита
fdo28551: 命令找不到
fdo28551: コマンドが見つかりません