faireboot: 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/faireboot - from package: fai-nfsroot

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

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