[Qemu-devel] Re: Problems KVM-84

[Anthony Liguori <anthony@codemonkey.ws>]

Avi Kivity wrote:
> Jay Mann wrote:
>> Hi,
>>
>> I just downloaded built and installed kvm-84 on ubuntu Hardy x64  
>> 2.6.24-23-
>> server and I’m getting the following 2 problems that did not exists 
>> in kvm-83.
>>
>> 1.    The qemu emulater (bios screen) takes a long time to start (~10 
>> seconds), and subsequently Libvirt times out when I try to start a 
>> guest VM from virsh.    
>
> This is caused by qemu r6404:
>
> commit 5d4cbd78aa33f6d034a62207c99ad0b64af44621
> Author: aliguori <aliguori@c046a42c-6fe2-441c-8c8c-71466251a162>
> Date:   Thu Jan 22 18:57:22 2009 +0000
>
>    block-qcow2: keep highest allocated byte (Uri Lublin)
>      We want to know the highest written offset for qcow2 images.
>    This gives a pretty good (and easy to calculate) estimation to how
>    much more allocation can be done for the block device.
>      It can be usefull for allocating more diskspace for that image
>    (if possible, e.g. lvm) before we run out-of-disk-space
>      Signed-off-by: Uri Lublin <uril@redhat.com>
>    Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
>
> Scanning the file at startup is slow.  We need to find a better way.

Any quick ideas?  Seems like this is broken by design.  Unless we can 
find a quick fix, I'm going to revert this in the stable tree.

Regards,

Anthony Liguori