Hi All, I found after update my kernel from 3.0.25 to 3.2.12 or same with kernel 3.3 Disk performance inside VM reduced by 10x times!!! ( for both kvm 0.12.5 and qemu 1.0.1) For example restore postgresql database in kernel 3.0.25 took only 48sec, while in 3.2.12 or 3.3 more than 9m command to launch VM: qemu-system-x86_64 -m 512 -drive file=/Virtual/sql.raw,if=virtio,cache=none -enable-kvm or raw lvm disk: qemu-system-x86_64 -m 512 -drive file=/dev/V1/sqltest,if=virtio,cache=none -enable-kvm than in VM: time cat 20120323.sql | psql dbtest -U dbtest results: kernel 3.0.25 real 0m53.659s user 0m1.587s sys 0m2.362s kernel 3.2.12 ( or 3.3 - similar results ) real 9m6.563s user 0m4.508s sys 0m1.752s in vmware 8 ws (kernel 3.3): real 0m41.765s user 0m2.468s sys 0m1.068s Any explanation for that? And how bring kvm back to speed? one more interesting test on kernel 3.2.12 assign lvm to iscsi ( using tgt) qemu-system-x86_64 -m 512 -drive file=/dev/sdg,if=virtio,cache=none -enable-kvm result: real 1m44.862s user 0m1.392s sys 0m0.612s -- -- Michael -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
