[virt-tools-list] Question about the image format
Cole Robinson
crobinso at redhat.com
Thu Apr 8 14:22:25 UTC 2010
On 04/08/2010 10:09 AM, Daniel P. Berrange wrote:
> On Thu, Apr 08, 2010 at 09:58:51AM -0400, Cole Robinson wrote:
>> On 04/07/2010 10:45 PM, Dustin Xiong wrote:
>>>
>>>
>>>
>>>> Date: Tue, 6 Apr 2010 14:17:47 +0800
>>>> Subject: Re: [virt-tools-list] Question about the image format
>>>> From: miles.kuo at gmail.com
>>>> To: x_k_123 at hotmail.com
>>>> CC: virt-tools-list at redhat.com
>>>>
>>>> The virt-manager supports it I think. I've tried it on
>>>> virt-manager-0.8.3 and it works well as the qemu-kvm commands.
>>>>
>>>> Could you paste your XML file of the VM under virt-manager here?
>>>>
>>> I can't create the VM, so I didn't have the XML file.
>>> But I could use the same way to create VM2. The only differences is the disk images.
>>> The vm2.img comes from this command : qemu-img create -f qcow vm2.img 4G
>>> The vm3.img comes from the command : qemu-img create -b vm1.img -f qcow vm3.img
>>>
>>> virsh # create vm3.xml
>>> error: Failed to create domain from vm3.xml
>>> error: internal error unable to start guest: qemu: could not open disk image /var/lib/libvirt/images/vm3.img
>>>
>>> virsh # create vm2.xml
>>> Domain vm2 created from vm2.xml
>>>
>>> The XML file as below:
>>> <domain type='kvm'>
>>> <name>vm2</name>
>>> <uuid>7cb40798-1247-85e3-5e5b-e044eafbfff3</uuid>
>>> <memory>524288</memory>
>>> <currentMemory>524288</currentMemory>
>>> <vcpu>1</vcpu>
>>> <os>
>>> <type arch='i686' machine='pc-0.11'>hvm</type>
>>> <boot dev='hd'/>
>>> </os>
>>> <features>
>>> <acpi/>
>>> <apic/>
>>> <pae/>
>>> </features>
>>> <clock offset='utc'/>
>>> <on_poweroff>destroy</on_poweroff>
>>> <on_reboot>restart</on_reboot>
>>> <on_crash>restart</on_crash>
>>> <devices>
>>> <emulator>/usr/bin/kvm</emulator>
>>> <disk type='file' device='disk'>
>>> <driver name='qemu' type='qcow'/>
>>> <source file='/var/lib/libvirt/images/vm2.img'/>
>>> <target dev='hda' bus='ide'/>
>>> </disk>
>>> <disk type='block' device='cdrom'>
>>> <driver name='qemu' type='raw'/>
>>> <target dev='hdc' bus='ide'/>
>>> <readonly/>
>>> </disk>
>>> <interface type='network'>
>>> <mac address='52:54:00:5d:2c:c6'/>
>>> <source network='default'/>
>>> </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>
>>>
>>>
>>> <domain type='kvm'>
>>> <name>vm3</name>
>>> <uuid>7cb40798-1247-85e3-5e5b-e044eafbfff3</uuid>
>>> <memory>524288</memory>
>>> <currentMemory>524288</currentMemory>
>>> <vcpu>1</vcpu>
>>> <os>
>>> <type arch='i686' machine='pc-0.11'>hvm</type>
>>> <boot dev='hd'/>
>>> </os>
>>> <features>
>>> <acpi/>
>>> <apic/>
>>> <pae/>
>>> </features>
>>> <clock offset='utc'/>
>>> <on_poweroff>destroy</on_poweroff>
>>> <on_reboot>restart</on_reboot>
>>> <on_crash>restart</on_crash>
>>> <devices>
>>> <emulator>/usr/bin/kvm</emulator>
>>> <disk type='file' device='disk'>
>>> <driver name='qemu' type='qcow'/>
>>> <source file='/var/lib/libvirt/images/vm3.img'/>
>>> <target dev='hda' bus='ide'/>
>>> </disk>
>>> <disk type='block' device='cdrom'>
>>> <driver name='qemu' type='raw'/>
>>> <target dev='hdc' bus='ide'/>
>>> <readonly/>
>>> </disk>
>>> <interface type='network'>
>>> <mac address='52:54:00:5d:2c:c6'/>
>>> <source network='default'/>
>>> </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>
>>>
>>>
>>>>> I use the command 'qemu-img create -b vm1.img -f qcow vdisk.img'
>>>>> create a new image vdisk.img. When I use virt-manager create a new VM based
>>>>> on vdisk.img, failed.
>>>>> The error as below:
>>>>>
>>>>> Unable to complete install '<class 'libvirt.libvirtError'> internal error
>>>>> unable to start guest: qemu: could not open disk image
>>>>> /media/disk/images/vdisk.img
>>>>>
>>>>> Traceback (most recent call last):
>>>>> File "/usr/local/share/virt-manager/virtManager/create.py", line 1437, in
>>>>> do_install
>>>>> dom = guest.start_install(False, meter = meter)
>>>>> File "/usr/local/lib/python2.6/dist-packages/virtinst/Guest.py", line 795,
>>>>> in start_install
>>>>> return self._do_install(consolecb, meter, removeOld, wait)
>>>>> File "/usr/local/lib/python2.6/dist-packages/virtinst/Guest.py", line 896,
>>>>> in _do_install
>>>>> self.domain = self.conn.createLinux(install_xml, 0)
>>>>> File "/usr/lib/python2.6/dist-packages! /libvirt.py", line 1077, in
>>>>> createLinux
>>>>> if ret is None:raise libvirtError('virDomainCreateLinux() failed',
>>>>> conn=self)
>>>>> libvirtError: internal error unable to start guest: qemu: could not open
>>>>> disk image /media/disk/images/vdisk.img
>>>>>
>>>>> But if I don't use virt-manager. I just use the command
>>>>> kvm -hda vdisk.img -m 1024 -cdrom rhel-server-5.4-i386-dvd.iso -boot d
>>>>> or kvm vdisk.img -m 1024
>>>>> The VM could running.
>>>>>
>>>>> So I want to ask whether the virt-manager support the disk created by
>>>>> 'qemu-img create -b vm1.img -f qcow vdisk.img' or not.
>>>>>
>>>>> Thank you very much.
>>>>>
>>
>> There is a similar bug already filed against libvirt in fedora:
>>
>> https://bugzilla.redhat.com/show_bug.cgi?id=579067
>>
>> I don't think the security drivers know to change permissions of qcow2
>> backing files when launching a domain.
>
> Yes they do know how to deal with backing files, at least in the current
> libvirt release.
Good to know, thanks. This is probably just an issue for Fedora 12 then
where we aren't running latest libvirt. Dustin, are you using F12? Might
what to check out the virt-preview repo:
http://jforbes.fedorapeople.org/virt-preview/README
- Cole
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