[Bug 517067] Re: Using virtio for block devices makes disks and partitions disappear in KVM/QEMU (using vmbuilder and libvirt)

[Andreas Ntaflos]

Thanks for the comment, but how do you figure? I did not change anything
after the fact, I modified the template used for installation and setup
of the guest domain.

First, it seems to depend on the bus type whether the virtual disks are
at all visible to QEMU, as can be seen from the screenshots. At that
point logical device names are of no consequence, yet, because the
kernel isn't even booted.

Second, it does not matter whether the disks are called "vda" or "hda"
(the default) in the libvirt domain definition. From the documentation:
"The dev attribute indicates the "logical" device name. The actual
device name specified is not guaranteed to map to the device name in the
guest OS. Treat it as a device ordering hint." This is further supported
by the fact that upon switching the bus type to "ide" the disks are
visible both to QEMU and to the booted guest Linux kernel but the
logical device name in the domain definition is still "vda"-based.

Third, the logical device name is defined and set early during
installation/setup of the guest since it looks at the modified template
in /etc/vmbuilder/libvirt. So the installation procedure is aware that
disks are named "vda" in the definition and takes that into account (or
should take that into account). It does not matter whether it is "hda"
oder "vda" there (I tried both, multiple times), /etc/fstab will always
have "/dev/sdX*" set.

So I don't think that is the problem here, but I will try again. Thanks
for the comment, again!

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Using virtio for block devices makes disks and partitions disappear in KVM/QEMU (using vmbuilder and libvirt)
https://bugs.launchpad.net/bugs/517067
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