vgchange: 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/vgchange - from package: lvm2

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

On Debian possible default full paths are:

/sbin/vgchange - from package: lvm2

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

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