Bug 1290296 - ostree+grub2 will not auto-regenerate root=UUID=
ostree+grub2 will not auto-regenerate root=UUID=
Product: Fedora
Classification: Fedora
Component: rpm-ostree (Show other bugs)
Unspecified Unspecified
unspecified Severity unspecified
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Assigned To: Colin Walters
Fedora Extras Quality Assurance
Depends On:
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Reported: 2015-12-10 01:08 EST by Chris Murphy
Modified: 2016-12-20 11:52 EST (History)
2 users (show)

See Also:
Fixed In Version:
Doc Type: Bug Fix
Doc Text:
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Clone Of:
Last Closed: 2016-12-20 11:52:15 EST
Type: Bug
Regression: ---
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oVirt Team: ---
RHEL 7.3 requirements from Atomic Host:
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Attachments (Terms of Use)
grub.cfg post upgrade (4.28 KB, text/plain)
2015-12-10 01:12 EST, Chris Murphy
no flags Details
bash -x grub2-mkconfig (9.06 KB, text/plain)
2015-12-10 01:16 EST, Chris Murphy
no flags Details

  None (edit)
Description Chris Murphy 2015-12-10 01:08:33 EST
Description of problem:

After using rpm-ostree upgrade, the resulting system doesn't reboot either tree because the grub.cfg contains the wrong root=UUID. Instead of containing the UUID for the actual root fs, it contains the UUID for the OS it was originally installed to.

Version-Release number of selected component (if applicable):


How reproducible:
Once, only one new tree to test right now

Steps to Reproduce:
1. rpm-ostree upgrade
2. reboot either 23 or 23.29 trees

Actual results:

Boot fails because root=UUID=24e16099-88fc-4a84-96d8-eabea2cbef82 specified in the grub.cfg doesn't exist.

Since the original grub.cfg is wiped out in the course of the ugprade, both trees have the wrong UUID, so rollback doesn't work.

Expected results:

Should boot. The grub.cfg should have root=UUID=8b0c4840-4fc7-4782-a4c0-25fec8a40dd4.

Additional info:

Normally I'd use 'bash -x grub2-mkconfig' to figure out why/how it's pulling in wrong information like this. But that command, and even "grub2-mkconfig" as root in a normal shell produces a menu entry free configuration - nothing is listed under the 15_ostree header at all. Is ostree/rpm-ostree running grub2-mkconfig is some kind of chroot or other environment that'd cause it to produce different results than directly calling that script from the command line?
Comment 1 Chris Murphy 2015-12-10 01:12 EST
Created attachment 1104217 [details]
grub.cfg post upgrade

grub.cfg created via 'rpm-ostree upgrade' (presumably calling grub2-mkconfig)

This file has the wrong root=UUID= value as boot param.
Comment 2 Chris Murphy 2015-12-10 01:16 EST
Created attachment 1104218 [details]
bash -x grub2-mkconfig

This is the output from 'bash -x grub2-mkconfig' which shows it's aware of the correct UUID for root. But it doesn't contain the menu entries for some reason, as if there's a difference in a regular shell environment calling grub2-mkconfig, and rpm-ostree calling it. (?) Weird. Makes this harder to troubleshoot.
Comment 3 Chris Murphy 2015-12-10 01:21:55 EST
OK so I'm finding the wrong UUID is in /boot/loader.1/entries/*.conf which are then pulled into the grub.cfg by grub2-mkconfig. Now the question is what creates those conf files? And does is just copy root=UUID= from an earlier conf file, or does it determine it some other way?

Normally grub2-mkconfig determines this via grub2-probe, but ostree/rpm-ostree seems to inhibit that in favor of it's own determination of the root fs UUID.
Comment 4 Colin Walters 2015-12-16 10:03:35 EST
This is an Anaconda install?  I'll take a look.
Comment 5 Colin Walters 2015-12-16 10:20:57 EST
Oh, this is for your clone-installed-system-to-btrfs thing?  Yeah, so OSTree indeed owns the bootloader config and propagates the whole kernel command line forward from the loader config files.

If you change your clone script to edit the UUID in the loader files, that should fix it.
Comment 6 Chris Murphy 2015-12-16 11:38:42 EST
The clone script was just btrfs send/receive, there isn't that much to clean up. Manually I modified ostree-fedora-atomic-0.conf and ostree-fedora-atomic-1.conf with the correct volume UUID and the problem is fixed. It's a really minor regression that grub isn't permitted to insert the correct root=UUID= as it's really unlikely the UUID changes from installation.

The cloning is a work around for bug 1289752.
Comment 7 Fedora End Of Life 2016-11-24 09:07:50 EST
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Comment 8 Fedora End Of Life 2016-12-20 11:52:15 EST
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