Thanks for the detailed info. I agree that disk starvation should not happen. Though it could be that deadline just about covers some other problem. There are a few pieces that add to slow down the host io, the RAID1 and the qcow2 file image. Using the IDE emulation would actually slow down the guest. But, and I am speculating here a bit, having the rsync going on while the guest writes to the virtual disk may just get delayed a bit over the timeout that the IDE driver expects some answer from the emulated drive. And if that is the case then there could be some potential of this to happen regardless of the scheduler choice. It just happens to help in your case. I did not see the same problems on a local setup with cfq, but then I had a raw image and were using virtio. I will try to adapt this setup to at least having qcow2 and emulated disks to see whether that reproduces the problems. If possible I would like to keep my RAID5 the way it is. ;)
-- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1008400 Title: Ubuntu server uses CFQ scheduler instead of deadline To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1008400/+subscriptions -- ubuntu-bugs mailing list [email protected] https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
