arcplugin: command not found

Have You tried accessing the binary with the full path?

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/arcplugin - from package: nordugrid-arc-devel

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

On Debian possible default full paths are:

/usr/bin/arcplugin - from package: nordugrid-arc-dev
/usr/lib/debug/usr/bin/arcplugin - from package: nordugrid-arc-dbg

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