fence_check: 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_check - from package: cman

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

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