4 Dec
2016
4 Dec
'16
6:33 p.m.
On Sun, 4 Dec 2016, Jonas Maebe wrote:
Francois Gouget wrote:
Indeed during the revert vm1 shows no read traffic (lots of RAM to cache that), but a steady 6 MB/s stream of writes ! In contrast on vm2 writes quickly ramp up to 80 MB/s, then stop after ~5 seconds and QEMU just uses CPU for the last ~4 seconds.
Maybe vm2 mounts its file systems with noatime?
The VM hosts all use relatime which provides essentially all the benefits of noatime. But in this case I expect the writes all go to the qcow2 disk image and I know vm1 is capable of sustaining more than 6 MB/s writes (e.g. when copying >100 GB around). -- Francois Gouget <fgouget(a)codeweavers.com>