certmaster-sync: 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-sync - from package: certmaster

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

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