gridftpd: 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/sbin/gridftpd - from package: nordugrid-arc-gridftpd

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

On Debian possible default full paths are:

/usr/sbin/gridftpd - from package: nordugrid-arc-gridftpd
/usr/lib/debug/usr/sbin/gridftpd - from package: nordugrid-arc-dbg

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

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