B.6. Guest virtual machine booting stalls with error: No boot device
- Symptom
- After building a guest virtual machine from an existing disk image, the guest booting stalls with the error message
No boot device. However, the guest virtual machine can start successfully using theQEMUcommand directly. - Investigation
- The disk's bus type is not specified in the command for importing the existing disk image:
# virt-install \ --connect qemu:///system \ --ram 2048 -n rhel_64 \ --os-type=linux --os-variant=rhel5 \ --disk path=/root/RHEL-Server-5.8-64-virtio.qcow2,device=disk,format=qcow2 \ --vcpus=2 --graphics spice --noautoconsole --import
However, the command line used to boot up the guest virtual machine using QEMU directly shows that it usesvirtiofor its bus type:# ps -ef | grep qemu /usr/libexec/qemu-kvm -monitor stdio -drive file=/root/RHEL-Server-5.8-32-virtio.qcow2,index=0,if=virtio,media=disk,cache=none,format=qcow2 -net nic,vlan=0,model=rtl8139,macaddr=00:30:91:aa:04:74 -net tap,vlan=0,script=/etc/qemu-ifup,downscript=no -m 2048 -smp 2,cores=1,threads=1,sockets=2 -cpu qemu64,+sse2 -soundhw ac97 -rtc-td-hack -M rhel5.6.0 -usbdevice tablet -vnc :10 -boot c -no-kvm-pit-reinjectionNote thebus=in the guest's XML generated by libvirt for the imported guest:<domain type='qemu'> <name>rhel_64</name> <uuid>6cd34d52-59e3-5a42-29e4-1d173759f3e7</uuid> <memory>2097152</memory> <currentMemory>2097152</currentMemory> <vcpu>2</vcpu> <os> <type arch='x86_64' machine='rhel5.4.0'>hvm</type> <boot dev='hd'/> </os> <features> <acpi/> <apic/> <pae/> </features> <clock offset='utc'> <timer name='pit' tickpolicy='delay'/> </clock> <on_poweroff>destroy</on_poweroff> <on_reboot>restart</on_reboot> <on_crash>restart</on_crash> <devices> <emulator>/usr/libexec/qemu-kvm</emulator> <disk type='file' device='disk'> <driver name='qemu' type='qcow2' cache='none'/> <source file='/root/RHEL-Server-5.8-64-virtio.qcow2'/> <emphasis role="bold"><target dev='hda' bus='ide'/></emphasis> <address type='drive' controller='0' bus='0' unit='0'/> </disk> <controller type='ide' index='0'/> <interface type='bridge'> <mac address='54:52:00:08:3e:8c'/> <source bridge='br0'/> </interface> <serial type='pty'> <target port='0'/> </serial> <console type='pty'> <target port='0'/> </console> <input type='mouse' bus='ps2'/> <graphics type='vnc' port='-1' autoport='yes' keymap='en-us'/> <video> <model type='cirrus' vram='9216' heads='1'/> </video> </devices> </domain>The bus type for the disk is set aside, which is the default value set by libvirt. This is the incorrect bus type, and has caused the unsuccessful boot for the imported guest. - Solution
Procedure B.2. Correcting the disk bus type
- Undefine the imported guest, then re-import it with
bus=virtioand the following:# virsh destroy rhel_64 # virsh undefine rhel_64 # virt-install \ --connect qemu:///system \ --ram 1024 -n rhel_64 -r 2048 \ --os-type=linux --os-variant=rhel5 \ --disk path=/root/RHEL-Server-5.8-64-virtio.qcow2,device=disk,bus=virtio,format=qcow2 \ --vcpus=2 --graphics spice --noautoconsole --import - Edit the imported guest's XML using
virsh editand correct the disk bus type.
