[libvirt-users] The emergence of virtual machines, probabilistic copy large file rate is very low

hi all: I used openstack+ceph to create a virtual machine for the window 2008 Enterprise Edition sp2. Now I find that almost every day I copy a large 60G file for the first time under two different folders on the same disk. Replication rate occurs only 2MB/s. But after this copy is finished, it is normal to copy again, and it can reach 70MB/s. But the first time the second day of the same operation, it will appear again. Not necessarily every day, of course any help will be appricate Wang Liming