This is my ceph performance data: Total time run: 30.370630 Total writes made: 849 Write size: 4194304 Bandwidth (MB/sec): 111.819 Stddev Bandwidth: 21.6665 Max bandwidth (MB/sec): 124 Min bandwidth (MB/sec): 0 Average IOPS: 27 Average Latency(s): 0.572236 Stddev Latency(s): 0.421846 Max latency(s): 4.06547 Min latency(s): 0.121321 Thanks! chagg at foxmail.com From: Chris Friesen Date: 2017-08-24 23:14 To: openstack at lists.openstack.org Subject: Re: [Openstack] guest rbd block device speed limit On 08/24/2017 01:04 AM, chagg at foxmail.com wrote: > Hello: > I am using openstack + libvirt + qemu-kvm. The speed of copying files > between virtual machines exceeds 300M Byte per second but the speed of dd command: > "watch dd oflag=direct,nonblock if=/dev/zero of=/opt/iotest1 bs=4M count=10" > is around 20M byte per second. Every guest is the same, and there is no io > tuning in libvirt. What can I do to unleash the speed of disk io speed inside > the guest? > Thanks! It looks like you're using ceph for your root disk. What sort of performance do you get accessing the ceph volumes from the host? Chris _______________________________________________ Mailing list: http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack Post to : openstack at lists.openstack.org Unsubscribe : http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.openstack.org/pipermail/openstack/attachments/20170825/ca520cd3/attachment.html>