createrepo_c: 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/createrepo_c - from package: createrepo_c

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

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