showmount: 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/showmount - from package: nfs-utils

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

On Debian possible default full paths are:

/sbin/showmount - from package: nfs-common

You may install the required package with command apt-get install {package}

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