carbon-sync: command not found

Have You tried accessing the binary with the full path?

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/carbon-sync - from package: carbonate

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