Boot CoreOS in secondary disk from the CoreOS GRUB in primary disk


I have a system with two hard disks and in both of them I installed a custom Fedora CoreOS image. The custom image has an additional GRUB menu entry to to chain-load the CoreOS bootloader in the second hard disk from the CoreOS GRUB in the first hard disk. The custom menu entry looks like:

menuentry "Second FCOS" { 

  set root=(hd1,gpt3) 

  chainloader +1 



But every time I select the “Second FCOS” option I get the following output:

And some seconds later, the system gets back automatically to the GRUB menu of the initial/first CoreOS.

Does someone know what could be missing or if there’s another way to boot a CoreOS image installed in the second disk from the CoreOS GRUB in the first hard disk?

Thanks in advance!

Unfortunately I think you’re going to have pain here too. We use partition and filesystem labels quite a bit and we assume them to be unique. For example, with two disks both with FCOS you’ll have two filesystems with the root label that will race on startup. Which one wins? Nobody knows.

Sorry I don’t have better answers for you on this.


Thanks for your response! The FCOS installed in the first disk (hd0) always boots first, the problem is how to boot the FCOS installed in the second disk (hd1) from the FCOS GRUB menu/console in hd0. Not sure if other environment variables apart from root also need to be updated.

Dusty’s point was that even if you fix the bootloader issue, FCOS can’t handle having two FCOS installs visible on the system at the same time. Fedora CoreOS is designed for server setups where it’s the only OS on the machine.

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