Have you tried virtio for storage? http://www.linux-kvm.org/page/Virtio
Enviado desde mi iPhone, perdona la brevedad El 26/03/2012, a las 14:59, Martin van Wilderen - JDN BV <[email protected]> escribió: > Hi List, > > I have a question about KVM disk performance. We are using Openstack Nova on > three machines. These machines have a SSD drive with a dd write performance > of about 130mb/s > > Within the instance the write performance is down to about 5 mb/s. When using > the allocate trick (dd zero to disk before newfs) we get a performance of 20 > mb/s. > > Things a have tried but don't give any extra results are: > - Settings the disklayout from qcow2 to raw > - Settings the cache type in libvirt.xml (writeback, writethrough, none) > - Switching KSM on and off. > - Tested with different guests OS, Linux, FreeBSD, Windows. > > Is there someone who had some extra info i can check? Or are there more > people with this issue? > > Snippet from libvirt.xml > <driver type='qcow2'/ cache='writeback'/> > <source file='/var/lib/nova/instances/instance-00000113/disk'/> > <target dev='vda' bus='virtio'/> > > Kind regards, > > Martin > _______________________________________________ > Mailing list: https://launchpad.net/~openstack > Post to : [email protected] > Unsubscribe : https://launchpad.net/~openstack > More help : https://help.launchpad.net/ListHelp _______________________________________________ Mailing list: https://launchpad.net/~openstack Post to : [email protected] Unsubscribe : https://launchpad.net/~openstack More help : https://help.launchpad.net/ListHelp
