vshelper: 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 Debian possible default full paths are:

/sbin/vshelper - from package: util-vserver

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

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