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

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

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