mf: 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/mf - from package: texlive-utils

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

On Debian possible default full paths are:

/usr/bin/mf - from package: texlive-binaries

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

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