certmaster-ca: 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/certmaster-ca - from package: certmaster

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

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