[Pkg-libvirt-maintainers] Bug#594962: libvirt-bin: VMs using qcow2 fail to start with 0.8.3-1: "No bootable device"

[John Pearson]

Package: libvirt-bin
Version: 0.8.3-1
Severity: important


I have a number of VMS which use qcow2 files as disks.

After upgrading to 0.8.3-1 they failed to boot, with messages like "No
bootable device".

The issue appears to be that the XML files in /etc/libvirt-bin/qemu
contain disk definitions like

    <disk type='file' device='disk'>
      <driver name='qemu'/>
      <source file='/var/local/qemu/images/laurel.qcow2'/>
      <target dev='vda' bus='virtio'/>
      <address type='pci' domain='0x0000' bus='0x00' slot='0x05'
function='0x0'/>
    </disk>

Note that the "driver" element does not include the "type" attribute.

Adding "type='qcow2'" to the driver element and restarting libvirt-bin
resolves the issue, but not before seriously stressing out the operator
:)

Virt-manager does not provide a mechanism for specifying the format of
existing disk files, and adding a new disk based on an existing qcow2
file silently specifies "type='raw'", whereas previously it simply
omitted the attribute and appeared to determine it automatically at 
run time; the new version assumes existing files are raw images, both
for exisitng VMs with no 'type' attribute, and when adding an existing
disk image to a VM.

I appreciate that automatically determining the image format is
hazardous when one of the options is 'raw', but please add something to
README.Debian and ideally notify the operator about this change in
behaviour if they have VMs defined that don't specify the format of
a disk image.

I'm separately filing a wishlist bug against virt-manager, asking for
the option to specify the format of existing disk image files.

-- System Information:
Debian Release: squeeze/sid
  APT prefers testing
  APT policy: (500, 'testing')
Architecture: amd64 (x86_64)

Kernel: Linux 2.6.35-0briar (SMP w/2 CPU cores)
Locale: LANG=en_AU.UTF-8, LC_CTYPE=en_AU.UTF-8 (charmap=UTF-8)
Shell: /bin/sh linked to /bin/dash

Versions of packages libvirt-bin depends on:
ii  adduser                   3.112          add and remove users and groups
ii  libavahi-client3          0.6.26-1       Avahi client library
ii  libavahi-common3          0.6.26-1       Avahi common library
ii  libblkid1                 2.17.2-3.1     block device id library
ii  libc6                     2.11.2-2       Embedded GNU C Library: Shared lib
ii  libcap-ng0                0.6.4-1        An alternate posix capabilities li
ii  libdevmapper1.02.1        2:1.02.48-3    The Linux Kernel Device Mapper use
ii  libgcrypt11               1.4.5-2        LGPL Crypto library - runtime libr
ii  libgnutls26               2.8.6-1        the GNU TLS library - runtime libr
ii  libnl1                    1.1-5          library for dealing with netlink s
ii  libparted0debian1         2.3-1          The GNU Parted disk partitioning s
ii  libpciaccess0             0.12.0-1       Generic PCI access library for X
ii  libreadline6              6.1-3          GNU readline and history libraries
ii  libsasl2-2                2.1.23.dfsg1-5 Cyrus SASL - authentication abstra
ii  libudev0                  160-1          libudev shared library
ii  libuuid1                  2.17.2-3.1     Universally Unique ID library
ii  libvirt0                  0.8.3-1        library for interfacing with diffe
ii  libxenstore3.0            4.0.1~rc6-1    Xenstore communications library fo
ii  libxml2                   2.7.7.dfsg-4   GNOME XML library
ii  logrotate                 3.7.8-6        Log rotation utility

Versions of packages libvirt-bin recommends:
ii  bridge-utils              1.4-5          Utilities for configuring the Linu
ii  dnsmasq-base              2.55-1         A small caching DNS proxy and DHCP
ii  gawk                      1:3.1.7.dfsg-5 GNU awk, a pattern scanning and pr
ii  iptables                  1.4.8-3        administration tools for packet fi
ii  libxml2-utils             2.7.7.dfsg-4   XML utilities
pn  netcat-openbsd            <none>         (no description available)
ii  qemu                      0.12.5+dfsg-1  fast processor emulator
ii  qemu-kvm                  0.12.5+dfsg-1  Full virtualization on x86 hardwar

Versions of packages libvirt-bin suggests:
ii  policykit-1                   0.96-2     framework for managing administrat

-- no debconf information