vgrep: 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:

/usr/bin/vgrep - from package: atfs

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

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