Re: [Qemu-discuss] gentoo linux, vanilla 3.10.23, libvirt 1.1.4, libvirt-glibc 0.1.7 , qemu 1.6.0-r1 problem with cache =none

[Fam Zheng]

On 2013年12月12日 20:13, Marko Weber | 8000 wrote:>
>>
>> Another question, what is the physical block size of the device for
>> your xfs partition?
>
>>
>> # lsblk -o NAME,PHY-SeC
>
> atabunka virtual # lsblk -o NAME,PHY-SeC
> NAME      PHY-SEC
> sda           512
> ├─sda1        512
> ├─sda2        512
> ├─sda3        512
> ├─sda4        512
> └─sda5        512
> sdb           512
> └─sdb1        512
>    └─md127    4096
> sdc           512
> └─sdc1        512
> sdd          4096
> └─sdd1       4096
>    └─md127    4096
> sde           512
> └─sde1        512
>    └─md127    4096
> sr0           512
>
> ahh yes, i can see now, the disks in the raid array have 4k sectors
>
>
>>
>> I think there is known problem with direct IO with 4K sector size,
>> someone in the community is working on it now.
>
> is this xfs related or qemu related. someone from the qemu / redhat
> community is working on it ?
>

This is qemu related. There are some new patches on qemu-devel to 
address this:

http://lists.gnu.org/archive/html/qemu-devel/2013-12/msg02180.html

Thanks,
Fam