newrelic-daemon: 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/newrelic-daemon - from package: newrelic-daemon

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

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