drbl-gen-ssh-host-keys: 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/drbl/sbin/drbl-gen-ssh-host-keys - from package: drbl

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

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