Re: [Libguestfs] debug a corrupted VHDX file with libguestfs
On Fri, Aug 04, 2023 at 10:37:50PM +0000, Lin, HongYi - Dell Team wrote:
I tried to recompile Ubuntu kernel and add some printk messages, they
don’t
show up in dmesg when I run
root@HenrikUbuntu2204:/mnt/sdj# guestmount -a
c1eef115-00000006-ec888b8d-64888b8d-00155000-4a448456 -m /dev/sda1 --ro /mnt/
sdk/
I guess the following messages are from libvirt / KVM ?
[ 46.629055] EXT4-fs (sda1): ext4_check_descriptors: Block bitmap for group
524288 not in group (block 0)!
[ 46.629656] EXT4-fs (sda1): group descriptors corrupted!
These messages are from the kernel.
However you will need to tell libguestfs to use your recompiled
kernel. This can be done easily by setting some environment
variables. This is what I do when I want to test a new kernel:
rm -rf /tmp/kernel/*
make
make INSTALL_MOD_PATH=/tmp/kernel modules_install
# In case the kernel modules are built with debug symbols:
find /tmp/kernel/ -name '*.ko' -exec strip --strip-debug {} \;
modules=`echo /tmp/kernel/lib/modules/*/`
export SUPERMIN_KERNEL=$PWD/arch/x86/boot/bzImage
export SUPERMIN_MODULES=$modules
rm -rf /var/tmp/.guestfs-`id -u`/
Then run guestmount in the usual way.
Rich.
--
Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones
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