On 04.05.2014 12:58, Luca Gervasi wrote: > Hello, > > i'm trying to convert my physical web servers to a virtual guest. What i'm > experiencing is a poor disk i/o, compared to the physical counterpart > (having strace telling me that each write takes approximately 100 times the > time needed on physical). > > Tested hardware is pretty good (HP Proliant 360p Gen8 with 2xSAS 15k rpm 48 > Gb Ram). > > The hypervisor part is a minimal Centos 6.5 with libvirt. > The guest is configured using: VirtIO as disk bus, qcow2 storage format > (thick allocation), cache mode: none (needed for for live migration - this > could be changed if is the bottleneck), IO mode: default. > > Is someone willing to give me some adivices? :) Have you tried using a raw images just for testing? I've seen some pretty nasty performance degradation with qcow2 but unfortunately I was never able to track down what exactly caused this. Switching to raw images fixed the issue for me. Regards, Dennis _______________________________________________ CentOS-virt mailing list CentOS-virt@xxxxxxxxxx http://lists.centos.org/mailman/listinfo/centos-virt
