Performance zfs

http://open-zfs.org/wiki/Performance_tuning#Alignment_Shift_.28ashift.29

choose correct value ashift

https://illumos.topicbox.com/groups/zfs/T2cf12f740806aa96-Ma3844bffd677334735f94f3d

understanding aio mode

https://specs.openstack.org/openstack/nova-specs/specs/mitaka/implemented/libvirt-aio-mode.html

option of qemu

https://heiko-sieger.info/qemu-system-x86_64-drive-options/

native or threads

https://www.reddit.com/r/VFIO/comments/9e3wwf/io_native_vs_threads_with_kvm_and_gpu_passthrough/

qemu disk with win10

http://turlucode.com/qemu-disk-io-performance-comparison-native-or-threads-windows-10-version/