Bug 2306035

Summary: [btrfs] kdump generates broken initrd with default config
Product: [Fedora] Fedora Reporter: Marius Vollmer <mvollmer>
Component: kdump-utilsAssignee: Lichen Liu <lichliu>
Status: CLOSED DUPLICATE QA Contact:
Severity: medium Docs Contact:
Priority: unspecified    
Version: 41CC: coxu, lichliu, mpitt
Target Milestone: ---Keywords: Regression
Target Release: ---Flags: ruyang: mirror+
Hardware: x86_64   
OS: Linux   
Whiteboard: CockpitTest
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Last Closed: 2025-11-24 08:08:42 UTC Type: ---
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Description Marius Vollmer 2024-08-20 12:52:41 UTC
kdump-utils-1.0.44-2.fc41.x86_64

Running "kdump rebuild" on a standard Fedora 41 cloud image produces a initrd that wont boot when the kernel crashes. It hangs waiting for a disk that will never appear:

[    **] Job dev-disk-by\x2dpath-pci\x2d0000…ice/start running (29s / no limit)

I think this happens because the kdump initrd has these arguments:

    # lsinitrd /boot/initramfs-6.11.0-0.rc3.30.fc41.x86_64kdump.img 
    Image: /boot/initramfs-6.11.0-0.rc3.30.fc41.x86_64kdump.img: 34M
    ========================================================================
    Version: dracut-102-3.fc41

    Arguments:  --add 'kdumpbase' --quiet --hostonly --hostonly-cmdline --hostonly-i18n --hostonly-mode 'strict' --hostonly-nics '' --aggressive-strip -o 'plymouth resume ifcfg earlykdump' --mount '/dev/disk/by-path/pci-0000:00:04.0-part /kdumproot  defaults' --squash-compressor 'zstd' --no-hostonly-default-device -f

Note the "--mount '/dev/disk/by-path/pci-0000:00:04.0-part /kdumproot  defaults'" part. /dev/disk/by-path/pci-0000:00:04.0-part is a directory, not a device node.

I think these arguments are wrong because /var is a btrfs subvolume:

    # findmnt /var
    TARGET SOURCE          FSTYPE OPTIONS
    /var   /dev/vda4[/var] btrfs rw,relatime,seclabel,compress=zstd:1,discard=async,space_cache=v2,subvolid=258,subvol=/var

Changing the "path" in kdump.conf to "/crash" (without "/var") produces a working initrd. It has these arguments:

    # lsinitrd /boot/initramfs-6.11.0-0.rc3.30.fc41.x86_64kdump.img 
    Image: /boot/initramfs-6.11.0-0.rc3.30.fc41.x86_64kdump.img: 35M
    ========================================================================
    Version: dracut-102-3.fc41

    Arguments:  --add 'kdumpbase' --quiet --hostonly --hostonly-cmdline --hostonly-i18n --hostonly-mode 'strict' --hostonly-nics '' --aggressive-strip -o 'plymouth resume ifcfg earlykdump' --mount '/dev/disk/by-uuid/98723e31-b94f-4b1f-a619-f08c352cf776 /sysroot btrfs rw,relatime,seclabel,compress=zstd:1,discard=async,space_cache=v2,subvolid=256,subvol=/root' --squash-compressor 'zstd' --no-hostonly-default-device -f


Reproducible: Always

Comment 1 Coiby 2024-08-21 07:54:38 UTC
I think this bug is the same as https://bugzilla.redhat.com/show_bug.cgi?id=2270423. So let me reassign it to Lichen.

Comment 2 Lichen Liu 2025-11-24 08:08:42 UTC
Hi Marius, this issue has the same root cause with 2357959, so let's track it in one ticket.

Thanks,
Lichen

*** This bug has been marked as a duplicate of bug 2357959 ***