celeryev: 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 CentOS possible default full paths are:

/usr/bin/celeryev - from package: python-celery

You may install the required package with command yum install {package}

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