vgsplit: 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/vgsplit - from package: lvm2

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

On Debian possible default full paths are:

/sbin/vgsplit - from package: lvm2

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

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