nova-scheduler: 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/nova-scheduler - from package: nova-scheduler

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

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