Re: [gentoo-amd64] Sanity check: systemd works with LVM2 root volume?

[Rich Freeman]

On Mon, Nov 30, 2015 at 12:24 PM, Steven Lembark <lembark@×××××××.com> wrote:
>
> I've tried tracing the logic produced by dracut to see why it failed,
> but at over 1000 lines I do not have time to verify its logic and see
> where it failed; ditto genkernel: there is too much logic to ignore
> checking modules that don't exist because they are in the kernel.
>

Did you try enabling debug output on dracut and an emergency shell?
The debug output is quite verbose in general and tends to give you a
good idea of where the problem lies (worst case you can add more
output if the specific function lacks it).  You can then try running
commands from the emergency shell to get root mounted and see if that
works, which will give you an idea of what is needed to fix the
problem.

As long as you mount the root on whatever mount point it creates
(/sysroot or something like that) and exit the shell, dracut will
attempt to complete the boot using the new root.

Oh, one other gotcha with dracut is that you need a valid /etc/fstab
for your root partition.  Since root is typically not mounted with
fstab with other initramfs systems sometimes it gets neglected.
Dracut attempts to mount it using its internal configuration, and then
remount it using the settings in /etc/fstab.  If you have a really
tricky setup there is also an fstab.sys module (or something along
those lines) that lets you create a special initramfs fstab in /etc
which contains just filesystems that need to be mounted early - dracut
embeds this file inside the initramfs and will mount everything it in
before launching init so it is useful if something like /sbin or
/usr/lib or whatever is on its own mountpoint).


-- 
Rich