DISKLESS_SERVER: 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/share/debian-lan-config/fai/config/files/usr/local/sbin/nbdswapd/DISKLESS_SERVER - from package: debian-lan-config

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

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