mirmon: 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/bin/mirmon - from package: mirmon

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

On Debian possible default full paths are:

/usr/bin/mirmon - from package: mirmon

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

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