fence_cisco_mds: 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_cisco_mds - 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_cisco_mds - from package: fence-agents

You may install the required package with command apt-get install {package}

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