On Fedora Rawhide, grub2-install fails in BIOS mode when the root filesystem is XFS, causing bootc and Anaconda installations to fail with: grub_fs_probe: unknown filesystem This is a regression compared to Fedora 43. The same workflow succeeds when using btrfs or when booting in UEFI mode. This breaks: bootc install to-disk Anaconda installer (BootloaderInstallationError) Environment: Fedora Rawhide (current) grub2 >= 2.12-49.fc44 (Rawhide) Boot mode: BIOS (i386-pc) Root filesystem: XFS Target disk: loopback device (/dev/loop0) Tooling: bootc + bootupd Reproducible: Always Steps to Reproduce: bootc install to-disk \ --disable-selinux \ --via-loopback \ --filesystem xfs \ --source-imgref docker://quay.io/centos-bootc/centos-bootc:stream10 \ ./disk.img bootc automatically enables --generic-image. Partitioning created by bootc: /dev/loop0p1 BIOS boot 1 MiB /dev/loop0p2 EFI System 512 MiB (vfat) /dev/loop0p3 Linux root 9.5 GiB (XFS) Filesystem creation: mkfs.xfs /dev/loop0p3 mkfs.fat /dev/loop0p2 Actual Results: Bootloader installation fails: Installing for i386-pc platform. /usr/sbin/grub2-install: error: ../grub-core/kern/fs.c:grub_fs_probe:123:unknown filesystem. bootc then aborts: error: boot data installation failed: installing component BIOS Failed to run "/usr/sbin/grub2-install" ... "/dev/loop0" Full command: grub2-install --target i386-pc \ --boot-directory /run/bootc/mounts/rootfs/boot \ --modules "mdraid1x part_gpt" \ /dev/loop0 Final failure: BootloaderInstallationError / Installing bootloader failed Expected Results: Installation should succeed and GRUB should be installed to the disk as it does on early Fedora rawhide or Fedora 43. Additional Information: This appears to be caused by recent GRUB changes in Rawhide (possibly related to stricter filesystem probing introduced by the GRUB OOM-fix series). Possibly related to Bug 2427945 (GRUB regression in Rawhide), but this issue affects BIOS + XFS during installation rather than UEFI boot at runtime.
Created attachment 2122138 [details] xfs error during grub2-install
Created attachment 2122139 [details] tail of verbose grub2-install command
Nicolas identified an upstream patch that fixes this, based on my testing. It will get to fedora soon. https://cgit.git.savannah.gnu.org/cgit/grub.git/commit/?id=1ed2628b560cedac7fd1a696985ab85b24541a8e
*** Bug 2430018 has been marked as a duplicate of this bug. ***
*** Bug 2430281 has been marked as a duplicate of this bug. ***
When I click on attachments in this bug I get "Sorry, you are not authorized to access attachment". I'd like to understand what feature of XFS grub-install is failing on.
Created attachment 2122761 [details] xfs error during grub2-install
Created attachment 2122762 [details] tail of verbose grub2-install command
sorry, Chris. You should be able to access the attachments now.
OK I'm seeing it in https://bugzilla.redhat.com/show_bug.cgi?id=2430281#c11 Looks like xfsprogs 6.18 adds XFS_SB_FEAT_INCOMPAT_PARENT flag at mkfs time. And that is one of the feature flag added by https://cgit.git.savannah.gnu.org/cgit/grub.git/commit/?id=1ed2628b560cedac7fd1a696985ab85b24541a8e
Yes, also XFS_SB_FEAT_INCOMPAT_EXCHRANGE , added to grub in the same commit.
Can we please have this fixed soon? It's extremely disruptive to testing; literally over 100 openQA compose tests fail because of this bug (every install that runs with the Server profile).
This update should contain the fix: https://bodhi.fedoraproject.org/updates/FEDORA-2026-384dcb944e
Awesome, yes, looks like it does. Now I can see all the other bugs that were hiding behind it!
With grub2-common-1:2.12-52.fc44.noarch I still see this almost same error in the image refreshes in anaconda-webui CI. Jan 26 12:26:46 ibm-p8-kvm-03-guest-02.virt.pnr.lab.eng.rdu2.redhat.com org.fedoraproject.Anaconda.Modules.Storage[6490]: INFO:program:Running in chroot '/mnt/sysroot'... gen_grub_cfgstub /boot/grub2 /boot/efi/EFI/fedora org.fedoraproject.Anaconda.Modules.Storage[6490]: INFO:program:grub2-probe: error: ../grub-core/kern/fs.c:grub_fs_probe:123:unknown filesystem. Jan 26 12:26:46 ibm-p8-kvm-03-guest-02.virt.pnr.lab.eng.rdu2.redhat.com org.fedoraproject.Anaconda.Modules.Storage[6490]: DEBUG:program:Return code of gen_grub_cfgstub: 1
Can you please point me to the rawhide image you are testing with ?
Last available from rawhide: https://fedora.mirror.garr.it/fedora/linux/development/rawhide/Server/x86_64/iso/Fedora-Server-dvd-x86_64-Rawhide-20260120.n.0.iso
Sorry, comment above is inaccurate: The CI test that we hit the failures against ran on the image with this checksum: SHA256 (Fedora-Server-netinst-x86_64-Rawhide-20260126.n.0.iso) = b2971bcc2cb89e2a607891aa76cfa6211148e5995e696ff13cf9467f86398e87
The issue is definitely resolved in openQA testing.