mount.9P: 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/sbin/mount.9P - from package: nfs-ganesha-mount-9P

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

Error in other languages:
mount.9P: bevel nie gevind nie
mount.9P: comandă negăsită
mount.9P: comando não encontrado
mount.9P: commande introuvable
mount.9P: command not found
mount.9P: käsku ei ole
mount.9P: không tìm thấy lệnh
mount.9P: komanda nerasta
mount.9P: Kommando nicht gefunden.
mount.9P: kommandot finns inte
mount.9P: komut yok
mount.9P: nie znaleziono polecenia
mount.9P: níor aimsíodh an t-ordú
mount.9P: no se encontró la orden
mount.9P: no s'ha trobat l'ordre
mount.9P: opdracht niet gevonden
mount.9P: parancs nem található
mount.9P: perintah tidak ditemukan
mount.9P: príkaz nenájdený
mount.9P: příkaz nenalezen
mount.9P: команда не найдена
mount.9P: командата не е открита
mount.9P: 命令找不到
mount.9P: コマンドが見つかりません