nova-clear-rabbit-queues: 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-clear-rabbit-queues - from package: nova-scheduler

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

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