jrgd

More or less yes, minus the copying files back if the operation was successful. You must be careful shrinking partitions as it is very easy to destroy them, and I’d have to guess the partition layout looks vaguely (EFI System Partition (/boot/efi), Boot (/boot), Root (/), …), which would require shrink and move of the partition before or after /boot. If you’re unfamiliar with shrinking a partition, a bit of reading into how it is done for your filesystem will be required. Different setups, ext4, btrfs, lvm, LUKS, etc. will have different requirements.

Checking the /boot size on my Fedora install, I partitioned out a gibibyte for the 3 kernel plus recovery kernel setup, which takes up about 338 MiB in total. Depending on out-of-tree kernel modules and bootloader modifications installed, your initramfs images could be larger. A few things to look for:

• the size of your current initramfs and vmlinuz image(s)
• any kernel modules you needed to install alongside your system (v4l2-loopback, nvidia, realtek, etc.)
• If there are other large files present in the boot partition

If everything there looks fine and/or is necessary, you might need to expand your /boot partition (either reinstall if new system or offline partition shrinking, moving after a data backup if you have personal files you care about).

You’re likely looking for this docs section for Caddy. The failure is the automated request to populate Caddy’s root CA cert to the host system, but obviously failed as it doesn’t have root permissions. As the docs state, if you intend to use the local HTTPS functionality of Caddy, you can manually run caddy trust privileged in order to populate the Caddy root CA cert manually. If you intend to disable the local HTTPS functionality (such as if you’re running Caddy behind a http reverse proxy), you can ignore the mail message.