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IDProjectCategoryView StatusLast Update
0001137channel: kernel/el8kernel-mlpublic2022-03-14 21:03
Reportergeorge.hansper Assigned Toburakkucat  
PrioritylowSeverityminorReproducibilityalways
Status closedResolutionno change required 
Summary0001137: kernel-ml 5.14.* fails to boot xen VMs - drops to dracut# prompt (missing driver xen-blkfront)
DescriptionAfter upgrading kernel-ml to 5.14.* xen virtual machines fail to boot, and drop back to the dracut:/# prompt

This is due to a missing driver xen-blkfront which is normally included by dracut when the initrd is created.

The dracut tool runs a command:

# /usr/lib/dracut/dracut-install -D /var/tmp/dracut.jxzXqv/initramfs -H --kerneldir /lib/modules/5.14.4-1.el8.elrepo.x86_64/ -m -o -s 'ahci_platform_get_resources|ata_scsi_ioctl|scsi_add_host|blk_cleanup_queue|register_mtd_blktrans|scsi_esp_register|register_virtio_device|usb_stor_disconnect|mmc_add_host|sdhci_add_host|scsi_add_host_with_dma' =drivers

In kernels up to 5.13.*, this would include the driver xen-blkfront.ko because the module contains the symbol `blk_cleanup_queue`

# nm xen-blkfront.ko | grep -E 'ahci_platform_get_resources|ata_scsi_ioctl|scsi_add_host|blk_cleanup_queue|register_mtd_blktrans|scsi_esp_register|register_virtio_device|usb_stor_disconnect|mmc_add_host|sdhci_add_host|scsi_add_host_with_dma'
                 U blk_cleanup_queue

In kernels 5.14.* this symbol is no longer present, due to changes in the kernel source code.
Steps To Reproduce
In a xen virtual machine:

In a xen virtual machine

# yum update kernel-ml
# reboot

Entering emergency mode. Exit the shell to continue.
Type "journalctl" to view system logs.
You might want to save "/run/initramfs/rdsosreport.txt" to a USB stick or /boot
after mounting them and attach it to a bug report.

dracut:/#
Additional InformationAs a solution for xen virtual machines, it is possible to add a file:
   /etc/dracut.conf.d/10-xen-blkfront.conf

with the contents:

   add_drivers+="xen-blkfront"

This forces the required kernel module xen-blkfront.ko to be included in the initrd by dracut.
TagsNo tags attached.

Relationships

related to 0001142 assignedburakkucat channel: kernel/el7 AWS EC2 non-nitro instances fail to boot via kernel-ml-5.14.X 

Activities

pperry

2021-09-20 07:30

administrator   ~0007850

Acknowledged, and thank you for the report.

As I read it, there is nothing for us to do here which would help. As you've identified, the solution is to manually recreate the initramfs with the missing module, and updating /etc/dracut.conf.d/10-xen-blkfront.conf as you state will ensure the module is always included in the initramfs image if it's not being included automatically.

Issue History

Date Modified Username Field Change
2021-09-20 01:44 george.hansper New Issue
2021-09-20 01:44 george.hansper Status new => assigned
2021-09-20 01:44 george.hansper Assigned To => burakkucat
2021-09-20 07:30 pperry Note Added: 0007850
2021-09-25 07:44 pperry Relationship added related to 0001142
2022-03-14 21:03 burakkucat Status assigned => closed
2022-03-14 21:03 burakkucat Resolution open => no change required