znol: 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/znol - from package: zephyr-clients

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

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