[Rdo-list] cinder retype and QoS

[Kashyap Chamarthy]

[. . .]

> From what I understand, retype needs to be implemented on a per driver
> level, and that’s simply not the case for the rbd driver yet.
> 
> Below is a small patch to the rbd driver that “implements” the retype
> function
> and subsequently allows for QoS changes of Cinder volumes on Ceph.
> 
> (Not sure at all if that breaks things elsewhere :)

If you have time, you might want to submit an upstream review 
request and let the CI infrastructure handle that for you.

--
/kashyap

> 
> —>
> # diff -u  /usr/lib/python2.6/site-packages/cinder/volume/drivers/rbd.py.orig
> /usr/lib/python2.6/site-packages/cinder/volume/drivers/rbd.py
> --- /usr/lib/python2.6/site-packages/cinder/volume/drivers/rbd.py.orig
> 	2014-11-19 11:44:43.739979396 +0100
> +++ /usr/lib/python2.6/site-packages/cinder/volume/drivers/rbd.py	2014-11-19
> 14:28:27.853345650 +0100
> @@ -651,6 +651,29 @@
>                  new_name = "%s.deleted" % (volume_name)
>                  self.rbd.RBD().rename(client.ioctx, volume_name, new_name)
> 
> +    def retype(self, ctxt, volume, new_type, diff, host):
> +        """Retype a volume, QoS change only."""
> +        LOG.info('Retype volume request %(vol)s to be %(type)s '
> +                 '(host: %(host)s), diff %(diff)s.' %
> +                 {'vol': volume['name'],
> +                  'type': new_type,
> +                  'host': host,
> +                  'diff': diff})
> +
> +        if volume['host'] != host['host']:
> +	      LOG.error('Retype with host migration not supported')
> +            return False
> +
> +        if diff['encryption']:
> +            LOG.error('Retype of encryption type not supported')
> +            return False
> +
> +        if diff['extra_specs']:
> +	      LOG.error('Retype of extra_specs not supported')
> +            return False
> +
> +        return True
> +
> <--
> 
> Cheers,
>  Arne
> 
> --
> Arne Wiebalck
> CERN IT
> 
>