Hi All, I hope this email finds you well. I am currently facing an issue with booting a VM using a custom-compiled kernel and would appreciate your expertise on the matter. ### Problem Description I have downloaded the `Fedora-Server-KVM-38-1.6.x86_64.qcow2` image and successfully booted it using `qemu-system-x86_64`. However, when I try to boot this VM with a custom-compiled kernel using the `-kernel` flag, it fails to boot. The root filesystem is on LVM, and it seems the kernel needs to activate volume groups before mounting the root filesystem. ### Steps Taken 1. Copied `/boot/config-*` from inside the VM and used it to build the kernel on the host machine. 2. Also tried `make localmodconfig` after copying `/boot/config-*`. 3. Built `initrd.img` using `dracut`. #### Dracut Command ```bash dracut initrd.img --kmoddir $INSTALL_MOD_PATH/lib/modules/6.4.0+ 6.4.0+ ``` #### Qemu Command ```bash qemu-system-x86_64 -enable-kvm -nographic -vga none -smp 1 -m 2G \ -kernel arch/x86_64/boot/bzImage -initrd initrd.img -append "root=/dev/vda3 ro console=ttyS0" \ -device virtio-blk-pci,drive=rootdisk -drive file=Fedora-Server-KVM-38-1.6.x86_64.qcow2,if=none,cache=none,id=rootdisk,format=qcow2 \ -net nic,model=virtio -net user,hostfwd=tcp::5555-:22 ``` ### Error Observed The kernel panics with the following message: ``` [ 0.843818] List of all partitions: [ 0.844084] fd00 7340032 vda [ 0.844086] driver: virtio_blk [ 0.844571] fd01 1024 vda1 f3137bf4-2cf0-4ef6-98a9-dda32e23ddcd [ 0.844573] [ 0.845269] fd02 1048576 vda2 3030ca3b-6606-4a8e-a5ee-efdc7858fb64 [ 0.845270] [ 0.845976] fd03 6288384 vda3 416b3009-59d3-4ed1-b126-3cb216aa02f4 [ 0.845976] [ 0.846593] fd10 20971520 vdb [ 0.846594] driver: virtio_blk [ 0.847091] 0b00 1048575 sr0 [ 0.847092] driver: sr [ 0.847545] No filesystem could mount root, tried: [ 0.847546] ext3 [ 0.847906] ext2 [ 0.848060] ext4 [ 0.848220] fuseblk [ 0.848362] xfs [ 0.848537] btrfs [ 0.848674] [ 0.848951] Kernel panic - not syncing: VFS: Unable to mount root fs on unknown-block(253,3) [ 0.849574] CPU: 0 PID: 1 Comm: swapper/0 Not tainted 6.4.0+ #3 [ 0.850012] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.2-0-gea1b7a073390-prebuilt.qemu.o4 [ 0.850837] Call Trace: [ 0.851109] <TASK> [ 0.851261] dump_stack_lvl+0x47/0x60 [ 0.851524] panic+0x178/0x330 [ 0.851745] mount_block_root+0x278/0x280 [ 0.852030] ? __pfx_ignore_unknown_bootoption+0x10/0x10 [ 0.852403] prepare_namespace+0x156/0x180 [ 0.852705] kernel_init_freeable+0x416/0x460 [ 0.853031] ? __pfx_kernel_init+0x10/0x10 [ 0.853328] kernel_init+0x1a/0x140 [ 0.853585] ret_from_fork+0x2c/0x50 [ 0.853858] </TASK> [ 0.854067] Kernel Offset: 0x16000000 from 0xffffffff81000000 (relocation range: 0xffffffff80000000-0xffffffffbfff) [ 0.854866] ---[ end Kernel panic - not syncing: VFS: Unable to mount root fs on unknown-block(253,3) ]--- ``` ### Additional Information - `/etc/fstab` and `lsblk` output are attached for reference. #### /etc/fstab ``` /dev/mapper/sysvg-root / xfs defaults 0 0 UUID=2cd18fbf-7705-4a86-8bb8-c18dafdee822 /boot ext4 defaults 1 2 ``` #### lsblk ``` NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINTS sr0 11:0 1 1024M 0 rom zram0 251:0 0 3.8G 0 disk [SWAP] vda 252:0 0 7G 0 disk ├─vda1 252:1 0 1M 0 part ├─vda2 252:2 0 1G 0 part /boot └─vda3 252:3 0 6G 0 part └─sysvg-root 253:0 0 6G 0 lvm / ``` #### lsinitrd initrd.img ``` Image: initrd.img: 49M ======================================================================== Version: dracut-049-223.git20230119.el8 Arguments: --force --kmoddir '$INSTALL_MOD_PATH/lib/modules/6.4.0+ 6.4.0+' dracut modules: bash systemd systemd-initrd nss-softokn i18n network-manager network ifcfg drm plymouth prefixdevname crypt dm kernel-modules kernel-modules-extra kernel-network-modules lvm resume rootfs-block terminfo udev-rules biosdevname dracut-systemd usrmount base fs-lib memstrack microcode_ctl-fw_dir_override shutdown ``` I would be grateful for any guidance or suggestions you could provide to resolve this issue. vishal.c _______________________________________________ linux-lvm mailing list linux-lvm@xxxxxxxxxx https://listman.redhat.com/mailman/listinfo/linux-lvm read the LVM HOW-TO at http://tldp.org/HOWTO/LVM-HOWTO/
