lcg-rf: 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/lcg-rf - from package: lcg-util

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

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