mb2md: 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/mb2md - from package: mb2md

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

On Debian possible default full paths are:

/usr/bin/mb2md - from package: mb2md

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

Error in other languages:
mb2md: bevel nie gevind nie
mb2md: comandă negăsită
mb2md: comando não encontrado
mb2md: commande introuvable
mb2md: command not found
mb2md: käsku ei ole
mb2md: không tìm thấy lệnh
mb2md: komanda nerasta
mb2md: Kommando nicht gefunden.
mb2md: kommandot finns inte
mb2md: komut yok
mb2md: nie znaleziono polecenia
mb2md: níor aimsíodh an t-ordú
mb2md: no se encontró la orden
mb2md: no s'ha trobat l'ordre
mb2md: opdracht niet gevonden
mb2md: parancs nem található
mb2md: perintah tidak ditemukan
mb2md: príkaz nenájdený
mb2md: příkaz nenalezen
mb2md: команда не найдена
mb2md: командата не е открита
mb2md: 命令找不到
mb2md: コマンドが見つかりません