Note: This bug is displayed in read-only format because
the product is no longer active in Red Hat Bugzilla.
RHEL Engineering is moving the tracking of its product development work on RHEL 6 through RHEL 9 to Red Hat Jira (issues.redhat.com). If you're a Red Hat customer, please continue to file support cases via the Red Hat customer portal. If you're not, please head to the "RHEL project" in Red Hat Jira and file new tickets here. Individual Bugzilla bugs in the statuses "NEW", "ASSIGNED", and "POST" are being migrated throughout September 2023. Bugs of Red Hat partners with an assigned Engineering Partner Manager (EPM) are migrated in late September as per pre-agreed dates. Bugs against components "kernel", "kernel-rt", and "kpatch" are only migrated if still in "NEW" or "ASSIGNED". If you cannot log in to RH Jira, please consult article #7032570. That failing, please send an e-mail to the RH Jira admins at rh-issues@redhat.com to troubleshoot your issue as a user management inquiry. The email creates a ServiceNow ticket with Red Hat. Individual Bugzilla bugs that are migrated will be moved to status "CLOSED", resolution "MIGRATED", and set with "MigratedToJIRA" in "Keywords". The link to the successor Jira issue will be found under "Links", have a little "two-footprint" icon next to it, and direct you to the "RHEL project" in Red Hat Jira (issue links are of type "https://issues.redhat.com/browse/RHEL-XXXX", where "X" is a digit). This same link will be available in a blue banner at the top of the page informing you that that bug has been migrated.
Description of problem:
In RHCOS, we support reprovisioning the root filesystem on first boot from the initramfs via Ignition.
For example, let's say the rootfs is an XFS filesystem on /dev/sda4 with label "root". So then /dev/disk/by-label/root points to /dev/sda4.
Given the right Ignition config (see example here: https://github.com/openshift/os/blob/8f1c54329f75c6cdac349ba2398c34c1812ef22d/tests/kola/luks/tpm/config.ign), RHCOS is able to save the rootfs to RAM, make /dev/sda4 a LUKS container, create a new XFS with label "root" on /dev/dm-0, then copy back the rootfs contents.
Most of the time after it does this, the /dev/disk/by-label/root symlink correctly points to the new device (/dev/dm-0). But sometimes, it seems like udev never received the event at all and so the symlink still points to /dev/sda4:
https://github.com/coreos/fedora-coreos-config/pull/779#issuecomment-745594090
Version-Release number of selected component (if applicable):
systemd-239-41.el8_3.1.x86_64
How reproducible:
One in... 5 runs maybe?
Steps to Reproduce:
1. Run the Ignition config linked above against an RHCOS 4.7 without the patch in https://github.com/coreos/fedora-coreos-config/pull/779
Actual results:
Works 100% of the time.
Expected results:
Sometimes fails because /dev/disk/by-label/root isn't updated. Failure mode looks like this:
https://github.com/coreos/fedora-coreos-config/pull/771#issuecomment-744756881.
Additional info:
- I'm not sure if udevd is necessarily to blame here or if it's the kernel. If the latter, feel free to move the component against that.
- AFAIK, we haven't noticed this in Fedora CoreOS, which could mean this is fixed in newer kernel/systemd.
Does this still happen on RHEL-8.4 or newer (systemd >= 239-44)? We backported the PR I mentioned in comment 1 in bug #1642728.
Comment 5RHEL Program Management
2022-06-17 07:27:27 UTC
After evaluating this issue, there are no plans to address it further or fix it in an upcoming release. Therefore, it is being closed. If plans change such that this issue will be fixed in an upcoming release, then the bug can be reopened.
(In reply to David Tardon from comment #4)
> Does this still happen on RHEL-8.4 or newer (systemd >= 239-44)? We
> backported the PR I mentioned in comment 1 in bug #1642728.
I briefly looked at this. I was surprised to find that even in Fedora land now we seem to be occasionally hitting this. I deduced this by grepping all available test results of Fedora CoreOS CI for all our upstream repos for 'Expected /dev/disk/by-label/.* triggering udev' (which is the text added by the workaround in https://github.com/coreos/fedora-coreos-config/pull/779) and getting many hits, especially related to RAID1 tests. So at this point, we'd need to unwind this upstream first anyway before checking that it's fixed downstream too. So let's keep this closed.