GRUB timeout on Fedora 22 / 23
On GNU/Linux systems, boot details are managed by GRUB system. GRUB is a nice way to set up boot and kernel options without some frustrating issues. GRUB is a Multiboot boot loader, something like the first software program that runs when a computer starts. GRUB is easy to configure and doesn’t need much work, but on modern PCs with UEFI and EFI and something different could cause some troubles.
The Fedora UEFI/EFI system (aka MacBook Pro)
Pay attention to working with GRUB, because GRUB problems will make your computer not able to boot.
Fedora, like many other Linux distributions, on UEFI/EFI systems (like the Apple MacBook Pro) reads the GRUB settings from a different location, so if you change the old /grub files nothing will be happen to your system boot. Actually, GRUB 2 has replaced what was formerly known as GRUB and the old GRUB has become GRUB Legacy.
So GRUB is fun and useful, but something wrong is dangerous.
Change the GRUB timeout value
To modify GRUB timeout value, we need to edit a GRUB configuration file, so open terminal console and type:
sudo vi /etc/default/grub
To modify GRUB timeout value, put the value to a different one, like:
GRUB_TIMEOUT=0 GRUB_HIDDEN_TIMEOUT=1 GRUB_HIDDEN_TIMEOUT_QUIET=true
With the 1 second hidden timeout, we have time to press ‘ESC’ and to enter in GRUB menu.
After, we need to regenerate the GRUB configuration file, so put this:
grub2-mkconfig -o /boot/efi/EFI/fedora/grub.cfg
Take a look that we used the new EFI directory instead of the old one(usual BIOS mode).
We can check the regenerated GRUB file:
And reboot it!