valknut: 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/valknut - from package: valknut

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

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