bandwidthd: 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/bandwidthd - from package: bandwidthd-pgsql
/usr/sbin/bandwidthd - from package: bandwidthd

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

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