whisper-aggregate: 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/whisper-aggregate - from package: carbonate

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

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