mksmbpasswd: 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 Debian possible default full paths are:

/usr/sbin/mksmbpasswd - from package: samba

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

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