** Project changed: qemu => qemu (Ubuntu) -- You received this bug notification because you are a member of qemu- devel-ml, which is subscribed to QEMU. https://bugs.launchpad.net/bugs/1201447
Title: Blue screen when disk uses cache='writeback' Status in qemu package in Ubuntu: New Bug description: I am running Windows 2008R2 as KVM guest on Ubuntu 12.04 hypervisor. Disk controller and network card are virtio devices with drivers from https://launchpad.net/kvm-guest-drivers-windows/+download (virtio-win-drivers-20120712-1.iso). Everything worked fine until I changed disk controller cache from the default (writethrough) to writeback. This introduced occasional blue screens. I noticed that they are linked to high disk IO. For example restoring over 1GB of backup files will results in a blue screen on around 4 out of 5 attempts. Also Windows update crashes the system sometimes. When idle the system will run fine for hours or sometimes even days. After removing cache='writeback' from the config everything came back to normal. qemu-kvm: Installed: 1.0+noroms-0ubuntu14.8 Candidate: 1.0+noroms-0ubuntu14.8 Version table: *** 1.0+noroms-0ubuntu14.8 0 500 http://archive.ubuntu.com/ubuntu/ precise-updates/main amd64 Packages 100 /var/lib/dpkg/status 1.0+noroms-0ubuntu14.7 0 500 http://security.ubuntu.com/ubuntu/ precise-security/main amd64 Packages 1.0+noroms-0ubuntu13 0 500 http://archive.ubuntu.com/ubuntu/ precise/main amd64 Packages To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/qemu/+bug/1201447/+subscriptions
