arcsync: 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/arcsync - from package: nordugrid-arc-client

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

On Debian possible default full paths are:

/usr/bin/arcsync - from package: nordugrid-arc-client

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

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