I have a slackware 14.1 guest that I use with qemu/kvm. I installed it using a normal harddrive which shows up as /dev/sda, but now I want to convert it. When I connect it as a virtio harddrive it shows up as /dev/vda.

I tried the following to convert the slackware installation. I booted with the livecd, mounted the harddrive at /mnt, set up bind mounts, and chrooted into /mnt.

Then I created an initrd image where I load virtio, virtio_blk and virtio_mmio drivers. I also make sure that initrd root is correct (/dev/vda2). I get no errors. Then I add initrd entry to /etc/lilo.conf and install lilo again with -b /dev/vda switch. I have also changed fstab to point to /vda instead of /sda.

When I try to boot with my new config I get the following errors:
no kernel modules found for linux 3.10.17-smp
mounting /dev/vda2 to /mnt failed
no /sbin/init found on rootdev.

When the boot process halts I get access to a shell where I can move around in initrd. Since the initrd image is on /dev/vda it seems like it's possible read /dev/vda despite the fact that no modules are loaded.

Any ideas?

You used -k 3.10.17 for mkinitrd?

1 members found this post helpful.

Yes I did.

maybe you should use UUID instead of raw device node? if you can access the system and run blkid (as root) on /dev/vda2 (are you sure it's /dev/vda2 and not /dev/vda1 ?) and replace /dev/vdaX with UUID={uuid} in the FSTAB maybe you will have better luck.

1 members found this post helpful.

The kernel version for which no modules could be found is "3.10.17-smp" by the way. Not "3.10.17"

2 members found this post helpful.

Thanks. I ran mkinitrd with -r 3.10.17-smp and now it works.