neutron-db-manage: 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/bin/neutron-db-manage - from package: neutron-common

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

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