QoS on Juno with RBD backend dont work for VM

[Ivan Arsenault]

Hi,
QoS for volume work with RBD but not for VM. So to solve this problem, you need to pass quota:disk_write_bytes_sec etc... extra parameters to VM.

At ligne 645/usr/lib/python2.7/site-packages/nova/virt/libvirt/imagebackend.py add this at the end on the «libvirt_info» method add this extra code :

Ex:
  def libvirt_info(self, disk_bus, disk_dev, device_type, cache_mode,
             extra_specs, hypervisor_version):
...
         if auth_enabled:
             info.auth_secret_type = 'ceph'
             info.auth_secret_uuid = CONF.libvirt.rbd_secret_uuid
+ tune_items = ['disk_read_bytes_sec', 'disk_read_iops_sec',
+ 'disk_write_bytes_sec', 'disk_write_iops_sec',
+ 'disk_total_bytes_sec', 'disk_total_iops_sec']
+ for key, value in extra_specs.iteritems():
+ scope = key.split(':')
+ if len(scope) > 1 and scope[0] == 'quota':
+ if scope[1] in tune_items:
+ setattr(info, scope[1], value)
        return info

after this patch, if you «dumpxml VM ID» with virsh you got the missing <iotune>...</iotune>

Ex:

virsh # dumpxml 2

...
   <disk type='network' device='disk'>
      <driver name='qemu' type='raw' cache='writeback'/>
      <auth username='cinder'>
        <secret type='ceph' uuid='9b576159-d403-4b1a-8aa2-f18cdcaf4f4b'/>
      </auth>
      <source protocol='rbd' name='vms/20c50d63-5af1-41a6-bc68-f0a6b9ffd715_disk'>
        <host name='192.168.76.120' port='6789'/>
        <host name='192.168.76.121' port='6789'/>
        <host name='192.168.76.122' port='6789'/>
      </source>
      <target dev='vda' bus='virtio'/>
      <iotune>
        <total_bytes_sec>83886080</total_bytes_sec>
        <total_iops_sec>15000</total_iops_sec>
      </iotune>
      <alias name='virtio-disk0'/>
      <address type='pci' domain='0x0000' bus='0x00' slot='0x04' function='0x0'/>
    </disk>
...

Voilà...

Ivan

[Joe Gordon (jogo)]

If you would like to submit a patch for this, please follow the instructions in: https://github.com/openstack/nova/blob/master/CONTRIBUTING.rst

[Ivan Arsenault (ivan-arsenault)]

Hi Joe,
           I am not developper. So if someone can do the patch for me that
will be fine. :-)
Thanks

Ivan

2014-12-08 10:14 GMT-05:00 Joe Gordon <email address hidden>:

> If you would like to submit a patch for this, please follow the
> instructions in:
> https://github.com/openstack/nova/blob/master/CONTRIBUTING.rst
>
>
> ** Changed in: nova
> Importance: Undecided => Wishlist
>
> ** Changed in: nova
> Status: New => Confirmed
>
> --
> You received this bug notification because you are subscribed to the bug
> report.
> https://bugs.launchpad.net/bugs/1399706
>
> Title:
> QoS on Juno with RBD backend dont work for VM
>
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>