xrdfs: 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/xrdfs - from package: xrootd-client

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

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