pacemakerd: command not found

Have You tried accessing the binary with the full path?

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/sbin/pacemakerd - from package: pacemaker

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