onnode: 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/onnode - from package: ctdb

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

On Debian possible default full paths are:

/usr/bin/onnode - from package: ctdb

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

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