On 01/09/2013 06:46 PM, Liu Yuan wrote: > I'll collect some numbers on it.
Well, when I use hdparm -W 0 /dev/vdx to choose the writethrough cache in the Guest (virtio disk), it says: test@vm1:~$ sudo hdparm -W 0 /dev/vdb /dev/vdb: setting drive write-caching to 0 (off) HDIO_DRIVE_CMD(identify) failed: Inappropriate ioctl for device HDIO_DRIVE_CMD(flushcache) failed: Inappropriate ioctl for device HDIO_DRIVE_CMD(setcache) failed: Inappropriate ioctl for device HDIO_DRIVE_CMD(identify) failed: Inappropriate ioctl for device HDIO_DRIVE_CMD(flushcache) failed: Inappropriate ioctl for device HDIO_DRIVE_CMD(identify) failed: Inappropriate ioctl for device Do I need extra flags to enable WCE? Both Guest and Host kernel is 3.7 and I start QEMU by following command: $ qemu-system-x86_64 --enable-kvm -drive file=~/images/test1,if=virtio,cache=writeback -smp 2 -cpu host -m 1024 -drive file=sheepdog:test,if=virtio,cache=writeback Thanks, Yuan
