On Tue, 28 May 2019 13:46:11 -0700 Samuel Sieb samuel@sieb.net wrote:
I'm still exploring BLS and UEFI, so the questions below might be naive.
On 5/28/19 1:23 PM, stan wrote:
On Tue, 28 May 2019 10:26:10 -0600 Chris Murphy lists@colorremedies.com wrote:
One possible gotcha is the boot volume needs to be big enough. For a few releases it's been 1GiB which probably is big enough for two Fedora's to share, because we don't use kdump by default whereas I guess it's configured on RHEL and that was the impetus behind the boot volume size change.
Does this larger boot volume have to be at the start of the drive. Could I re-purpose a swap partition into a boot volume?
The /boot partition can be anywhere. I generally don't even create a separate partition, it's just included in /. But if you're wanting to share it, it would need to be separate.
I just got into the habit when that was the recommended configuration, and haven't changed.
My understanding, after some reading, is that there has to be a separate /boot/efi partition, and that was where the BLS information resided. Except for people using systemd-boot, as described here, https://bugzilla.redhat.com/show_bug.cgi?id=1714007 and here, https://wiki.archlinux.org/index.php/Systemd-boot
So, couldn't there be a utility, which when the user points it at an alternate installation, it creates a link in the boot volume with priority. The way grub(1) used to do with the configfile entry.
You can still do that. Even with BLS I would expect you could add an entry in the static part of the grub.cfg to point to the other installation.
But aren't all these BLS scriptlets in the same partition for Fedora? I thought that under BLS the grub.cfg was just a dummy place holder, and all the heavy lifting was done by the scriptlets.
Another gotcha is on UEFI, the older Fedora during software updates will (rarely) need to update the bootloader which will step on the binary files in /boot/efi/EFI/fedora, which isn't the end of the world but it's probably better if the old Fedora /etc/fstab is modified to remove the automount of /boot/efi so that the EFI System partition isn't ever updated except by the new Fedora.
For a single large boot directory for all OSs on the system, couldn't there be a directory for each OS, allowing for both update and a boot selection screen (a menu of available OSs).
Probably, but you would somehow have to convince each OS install to update its own part.
Wouldn't that just be a symbolic link from the /boot(/efi) partiition to wherever the BLS scriptlets reside?
On UEFI the contents of the EFI system partition in EFI/fedora are blown away and replaced. It's been that way since we've had UEFI support as far as I can recall. The nice thing is that on Fedora 30 with BLS support, the grub.cfg on the ESP no longer contains the Fedora menu entries, those are now on the boot volume. So they will be preserved, but again they're ignored out of the box because we don't automatically share boot volumes.
I'm not familiar with the term ESP. From context, some kind of partition? Is the boot volume you refer to where the Fedora menu entries are stored /boot? Or a separate partition?
It's the EFI boot partition where the firmware knows to find the boot loaders. It's not /boot, it's normally mounted at /boot/efi.
And I don't have one. I think this is why my attempt to install as UEFI failed, because I used a custom configuration and didn't create a /boot/efi partition. But isn't the /boot/efi partition where the BLS scriptlets reside?