vgdisplay: 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:

/sbin/vgdisplay - from package: lvm2

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

On Debian possible default full paths are:

/sbin/vgdisplay - from package: lvm2

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

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