graphStats: 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/graphStats - from package: cjdns-graph

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

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