client_stats_9pOps: 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/client_stats_9pOps - from package: nfs-ganesha-utils

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

Error in other languages:
client_stats_9pOps: bevel nie gevind nie
client_stats_9pOps: comandă negăsită
client_stats_9pOps: comando não encontrado
client_stats_9pOps: commande introuvable
client_stats_9pOps: command not found
client_stats_9pOps: käsku ei ole
client_stats_9pOps: không tìm thấy lệnh
client_stats_9pOps: komanda nerasta
client_stats_9pOps: Kommando nicht gefunden.
client_stats_9pOps: kommandot finns inte
client_stats_9pOps: komut yok
client_stats_9pOps: nie znaleziono polecenia
client_stats_9pOps: níor aimsíodh an t-ordú
client_stats_9pOps: no se encontró la orden
client_stats_9pOps: no s'ha trobat l'ordre
client_stats_9pOps: opdracht niet gevonden
client_stats_9pOps: parancs nem található
client_stats_9pOps: perintah tidak ditemukan
client_stats_9pOps: príkaz nenájdený
client_stats_9pOps: příkaz nenalezen
client_stats_9pOps: команда не найдена
client_stats_9pOps: командата не е открита
client_stats_9pOps: 命令找不到
client_stats_9pOps: コマンドが見つかりません