In OpenStack, I am facing I/O performance issues. I am using virtio-scsi driver support in the quest. Currently, I am getting below mentioned performance.

WRITE: bw=37.2MiB/s (39.1MB/s), 37.2MiB/s-37.2MiB/s (39.1MB/s-39.1MB/s), io=4096MiB (4295MB), run=109977-109977msec

I got good performance enabling multi-queue virtio-scsi support in the guest. In order to do that I have to manually change in the VM's XML. Following are the changes:

<controller type='scsi' index='0' model='virtio-scsi'>
    <driver queues='N' /> <--- Added this line

Result: WRITE: bw=448MiB/s (470MB/s), 448MiB/s-448MiB/s (470MB/s-470MB/s), io=4096MiB (4295MB), run=9144-9144msec

My question is, is there any way we can configure this manual change by openstack parameter or any other automated way for new and running VMs?

I tried to search the option to set this parameter but couldn't find anything and also tried to tune other configurational parameters like chachemode but the performance was the same. However, there is a multi-queue enabling option in glance for network "hw_vif_multiqueue_enabled" with this option no success at all.

  • It seems this can be configured in Nova as of Train. See the release notes. – berndbausch Mar 1 at 8:36
  • Thank you Bernd for your quick response. Your suggestion was helpful :-) – gautam Mar 2 at 8:17

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