[systemd-devel] root= ignored

Chris Murphy lists at colorremedies.com
Thu Jan 29 08:38:19 PST 2015

On Thu, Jan 29, 2015 at 2:20 AM, Felix Miata <mrmazda at earthlink.net> wrote:
> I wrote "clone" for a reason. I don't "just copy" files. I clone (logical,
> root, autonomous) *partitions*, subsequently modifying only fstab, volume
> label and UUID before attempting boot from it.

Clone is a generic term, it doesn't require a particular process. Are
you changing the volume UUID with, e.g. tune2fs -U random?

>> files from old to new (I actually used btrfs send receive). I of
>> course had to install a new bootloader with grub2-install, and create
> The process I wrote was intended to make it clear that no bootloader that may
> have been on a Fedora / partition was used for booting a Fedora clone as
> adjusted to its new location. It's a process that was relatively simple and
> reliable until humanly memorable cmdline root= parameters what worked
> formerly began being disregarded by Fedora's boot process in apparent favor
> of incorporating a root filesystem UUID subject to change during
> backup/restore process in its initrd.

Like I said, I can't reproduce this behavior. The BIOS system boots
fine without rebuilding the initramfs just by changing fstab and
grub.cfg UUIDs to match the root volume's UUID. Therefore I see no
evidence root= is ignored on Fedora.

The failed UEFI boot is strictly due to the old ESP UUID not being
found. The failure has nothing to do with root=.

dracut -f -v --debug shows only on UEFI is there a wait for device by uuid
/usr/lib/dracut/modules.d/99base/module-setup.sh at 113(install):
wait_for_dev /dev/disk/by-uuid/5AC5-5766

Chris Murphy

More information about the systemd-devel mailing list