With info you provided, I think you have enabled rbd cache. As for performance improvement, it's related to your performance tests On Tue, Jul 8, 2014 at 8:34 PM, lijian <blacker1981 at 163.com> wrote: > Hello, > > I want to enable the qemu rbd writeback cache, the following is the settings > in /etc/ceph/ceph.conf > [client] > rbd_cache = true > rbd_cache_writethrough_until_flush = false > rbd_cache_size = 27180800 > rbd_cache_max_dirty = 20918080 > rbd_cache_target_dirty = 16808000 > rbd_cache_max_dirty_age = 60 > > and the next section is the vm definition xml: > <disk type='network' device='disk'> > <driver name='qemu' cache='writeback'/> > <auth username='estack'> > <secret type='ceph' uuid='101ae7dc-bd59-485e-acba-efc8ddbe0d01'/> > </auth> > <source protocol='rbd' name='estack/new-libvirt-image'> > <host name='X.X.X.X' port='6789'/> > </source> > <target dev='vdb' bus='virtio'/> > <address type='pci' domain='0x0000' bus='0x00' slot='0x07' > function='0x0'/> > </disk> > > my host OS is Ubuntu, kernel 3.11.0-12-generic, the kvm-qemu is > 1.5.0+dfsg-3ubuntu5.4, the guest os is Ubuntu 13.11 > ceph version is 0.80.1 (a38fe1169b6d2ac98b427334c12d7cf81f809b74) > > no performance improvements using the above cache settings, So what's wrong > with me, please help, thanks! > > Jian Li > > > > _______________________________________________ > ceph-users mailing list > ceph-users at lists.ceph.com > http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com > -- Best Regards, Wheat
 |