pvchange: 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/pvchange - from package: lvm2

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

On Debian possible default full paths are:

/sbin/pvchange - from package: lvm2

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

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