fence_hpblade: 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/sbin/fence_hpblade - from package: fence-agents

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

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