Merci Naziel, voilà les retours des commandes demandées :
fanfan@fanfan-VR630:~$ lsb_release -a
LSB Version: core-9.20160110ubuntu0.2-ia32:core-9.20160110ubuntu0.2-noarch:security-9.20160110ubuntu0.2-ia32:security-9.20160110ubuntu0.2-noarch
Distributor ID: Ubuntu
Description: Ubuntu 16.04.3 LTS
Release: 16.04
Codename: xenial
fanfan@fanfan-VR630:~$
fanfan@fanfan-VR630:~$ cat /etc/default/grub | grep GRUB_CMDLINE_LINUX_DEFAULT
GRUB_CMDLINE_LINUX_DEFAULT="quiet splash"
fanfan@fanfan-VR630:~$