uml_mconsole: 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/uml_mconsole - from package: uml_utilities

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

On Debian possible default full paths are:

/usr/bin/uml_mconsole - from package: uml-utilities

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

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