xrdadler32: 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/xrdadler32 - from package: xrootd-client

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

Error in other languages:
xrdadler32: bevel nie gevind nie
xrdadler32: comandă negăsită
xrdadler32: comando não encontrado
xrdadler32: commande introuvable
xrdadler32: command not found
xrdadler32: käsku ei ole
xrdadler32: không tìm thấy lệnh
xrdadler32: komanda nerasta
xrdadler32: Kommando nicht gefunden.
xrdadler32: kommandot finns inte
xrdadler32: komut yok
xrdadler32: nie znaleziono polecenia
xrdadler32: níor aimsíodh an t-ordú
xrdadler32: no se encontró la orden
xrdadler32: no s'ha trobat l'ordre
xrdadler32: opdracht niet gevonden
xrdadler32: parancs nem található
xrdadler32: perintah tidak ditemukan
xrdadler32: príkaz nenájdený
xrdadler32: příkaz nenalezen
xrdadler32: команда не найдена
xrdadler32: командата не е открита
xrdadler32: 命令找不到
xrdadler32: コマンドが見つかりません