momd: 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

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/momd - from package: mom

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