On Thu, Apr 23, 2015 at 5:51 PM, 张敏 <rudyflyzh...@gmail.com> 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
