firehol: 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:

/sbin/firehol - from package: firehol

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

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