vax: 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/vax - from package: simh

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

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