test_rt: 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/sbin/test_rt - from package: das-watchdog

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

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