gcdmaster: 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/gcdmaster - from package: gcdmaster

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

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