celeryd-multi: 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/celeryd-multi - from package: python-celery

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

On Debian possible default full paths are:

/usr/bin/celeryd-multi - from package: python-celery-common

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

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