myproxy-server-setup: 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 Debian possible default full paths are:

/usr/sbin/myproxy-server-setup - from package: myproxy-admin

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

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