rgmanager: 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/sbin/rgmanager - from package: rgmanager

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

On Debian possible default full paths are:

/usr/sbin/rgmanager - from package: rgmanager

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

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