Comment # 21 on bug 1156441 from Michael Chang

(In reply to Ignaz Forster from comment #20)
> (In reply to Michael Chang from comment #18)
> > Here the test package for grub2-install to set up $env_block in grubenv
> > file, Would you please take some time to test if it works as expected ?
> > 
> > https://build.opensuse.org/package/show/home:michael-chang:bsc:1156441/grub2
> 
> I just rebuilt the images with your modified grub version - everything
> expected by this patch is working perfectly fine now:
> * The grubenv file is present in the image with the env_block variable set.
> * Due to this variables can be set in GRUB also during first boot.
> * Modifying the variable with grub2-editenv in the running system still
> works.

Thanks for the testing and quick turnaround. I will commit it to factory if my
other test doesn't have problem.

> 
> Thanks a lot!
> 
> The other ticket is more or less independent of this patch: On read-only
> systems it may still be a good idea to be able to write the grub environment
> block. To make this possible the idea is to put the grubenv file onto a
> separate writable partition. I've currently implemented this using a
> subvolume called "/boot/writable", which will be created on read-only
> systems only, linking /boot/grub2/grubenv to /boot/writable/grubenv.
> This would be working in theory, but unfortunately KIWI deletes any files
> called /boot/*/grubenv, so this is not working for our images. On the other
> hand the solution is quite hacky (requiring to generate a GRUB script to run
> before the 00_header) and creates differences between a read-only and a
> read-write system, so I'm not really keen to keep it.
> A saner solutions seems to be to make grub2 use a different directory for
> grubenv from the beginning and uniformly for all systems (e.g. /boot/var).
> If you are not opposed to this I'd just develop a prototype to demonstrate
> what I mean.

Well. I think it inevitable to patch or supply new grub scripts for looking up
the grubenv in different directory. And to have grub-editenv to work uniformly
it seems symlink is better (like other distor did/does). Anyway having
prototype is a good idea to help understanding mutually.

Thanks.