hello I did not do windows vm on kvm since years but back in time for good io performance on windows vm on kvm virtio driver has to be installed. https://fedorapeople.org/groups/virt/virtio-win/direct-downloads/stable-virtio/virtio-win.iso oau Le jeudi 02 avril 2020 à 15:28 +0000, Frank Schilder a écrit : > Dear all, > > maybe someone can give me a pointer here. We are running OpenNebula > with ceph RBD as a back-end store. We have a pool of spinning disks > to create large low-demand data disks, mainly for backups and other > cold storage. Everything is fine when using linux VMs. However, > Windows VMs perform poorly, they are like a factor 20 slower than a > similarly created linux VM. > > If anyone has pointers what to look for, we would be very grateful. > > The OpenNebula installation is more or less default. The current OS > and libvirt versions we use are: > > Centos 7.6 with stock kernel 3.10.0-1062.1.1.el7.x86_64 > libvirt-client.x86_64 4.5.0- > 23.el7_7.1 @updates > qemu-kvm-ev.x86_64 10:2.12.0- > 33.1.el7 @centos-qemu-ev > > Some benchmark results from good to worse workloads: > > rbd bench --io-size 4M --io-total 4G --io-pattern seq --io-type write > --io-threads 16 : 450MB/s > rbd bench --io-size 4M --io-total 4G --io-pattern seq --io-type write > --io-threads 1 : 230MB/s > rbd bench --io-size 1M --io-total 4G --io-pattern seq --io-type write > --io-threads 1 : 190MB/s > rbd bench --io-size 64K --io-total 4G --io-pattern seq --io-type > write --io-threads 1 : 150MB/s > rbd bench --io-size 64K --io-total 1G --io-pattern rand --io-type > write --io-threads 1 : 26MB/s > > dd with conv=fdatasync gives awesome 500MB/s inside linux VM for > sequential write of 4GB. > > We copied a couple of large ISO files inside the Windows VM and for > the first ca. 1 to 1.5G it performs as expected. Thereafter, however, > write speed drops rapidly to ca. 25MB/s and does not recover. It is > almost as if Windows translates large sequential writes to small > random writes. > > If anyone has seen and solved this before, please let us know. > > Thanks and best regards, > > ================= > Frank Schilder > AIT Risø Campus > Bygning 109, rum S14 > _______________________________________________ > ceph-users mailing list -- ceph-users@xxxxxxx > To unsubscribe send an email to ceph-users-leave@xxxxxxx _______________________________________________ ceph-users mailing list -- ceph-users@xxxxxxx To unsubscribe send an email to ceph-users-leave@xxxxxxx
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