I read that installing grub on a new disk should be as simple as : sudo grub-install /dev/sdb (sdb being my "new" disk) sudo update-grub
Well it does not quite worked me.
My situation: I have a working linux install on an old disk I want to replace but keep as data storage / backup. (/dev/sda2) I have copied whole system over a new disk (/dev/sdb1)
When booting on my old disk, I have a nice boot menu offering to start ubuntu on either the old or the new disk and both are perfectly functionnal.
However when I boot up on my new disk from the bios I have a black screen for few seconds that explains it will be booting from (hd0,0) and after 5 seconds finally boots up normally.
I would like to set the new disk as default boot option, while having the same menu which is very convenient as it allows to boot on old system as back up.
What should it do ? I'm running ubuntu 16.04, perfectly working on both devices.