Re: [Qemu-block] [Question] the problem about driver-mirror

[Rudy Zhang]

On 2015/4/24 1:32, Stefan Hajnoczi wrote:
> On Thu, Apr 23, 2015 at 5:51 PM, 张敏 <address@hidden> wrote:
>> I test the function of driver-mirror when run io stress test in vm.
>> The fio's model is 128 iodepth, 4K block-size, 100% write, 100% randon.
>> This is a continuous test, and then I start drive-mirror to copy data
>> to other image file. I find this job can't finish.
>> I analysis the problem and find the dirty bitmap is always set, the job
>> can't converge.
>> Any ideas to solve this problem?
> 
> You can use QEMU I/O throttling to limit writes to the guest's disk so
> the mirror job can complete.
> 
> I don't have a magic number for you, but if you look at the rate at
> which the block job runs, make sure that the guest write throughput is
> limited below that number.
> 
> Stefan
> 
> 
Thank you very much for your suggestion.
I will try to use Qemu I/O throttling.

-- 
Best Regards
Rudy Zhang