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

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

On Debian possible default full paths are:

/usr/sbin/fence_egenera - from package: fence-agents

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