debian-edu-hd-warn: 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/debian-edu-hd-warn - from package: debian-edu-config

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

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