nmbd: 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/sbin/nmbd - from package: samba4
/usr/sbin/nmbd - from package: samba

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

On Debian possible default full paths are:

/usr/sbin/nmbd - from package: samba

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

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