User:Chrismurphy/Draft/dualboot teststation

Description

This test case creates a dual boot system with two Fedoras of different release versions, using btrfs snapshots, works as expected

Setup

1. Install Fedora 36. Any desktop, using Automatic partitioning.
2. Freshen your backups, just in case
3. Backup /boot/efi, just in case, e.g.
   1. cd /boot
   2. sudo tar -acf bootefibackup.tar efi

How to test

1. create a snapshot
2. edit the dnfconf,
3. dup the most recent bls snippet, modify its rootflags entry to match the snapshot name

Expected Results

1. GRUB menu shows boot options: variant+version+kernelversion for switching between the two.
2. Can also use grubby --set-default=/boot/vmlinuz-5.18.15-200.fc36.x86_64
3. Limitations:
   1. /boot is only 1GiB by default, so this is the limiting factor right now, how many Fedoras you can have installed at one time. Two is safe. Three is iffy unless (a) configure the test Fedora instances' dnf.conf such that the kernel is excluded from updates; (b) consider deleting the "rescue" initramfs and kernel for the test instances, also removing dracut-config-rescue-056-1.fc36.x86_64 from them so these files aren't recreated; or (c) put /boot on a Btrfs subvolume.