<div dir="ltr">Hello,<div><br></div><div> I'm very curious about this as well!</div><div><br></div><div> It would be awesome to support Cinder multi-attach when using Ceph... If the code is already there, how to use it?!</div><div><br></div><div>Cheers,</div><div>Thiago</div></div><br><div class="gmail_quote"><div dir="ltr" class="gmail_attr">On Mon, 27 May 2019 at 03:52, Bernd Bausch <<a href="mailto:berndbausch@gmail.com">berndbausch@gmail.com</a>> wrote:<br></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">
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<p>The Stein release notes mention that the RBD driver now supports
multiattach, but i have not found any details. Are there
limitations? Is there a need to configure anything?</p>
<p><a href="https://opendev.org/openstack/cinder/src/branch/master/cinder/volume/drivers/rbd.py#L767" target="_blank">In
the RBD driver</a>, I find this:</p>
<pre> def _enable_multiattach(self, volume):
multipath_feature_exclusions = [
self.rbd.RBD_FEATURE_JOURNALING,
self.rbd.RBD_FEATURE_FAST_DIFF,
self.rbd.RBD_FEATURE_OBJECT_MAP,
self.rbd.RBD_FEATURE_EXCLUSIVE_LOCK,
]</pre>
<p>This seems to mean that journaling and other features (to me,
it's not quite clear what they are) will be automatically disabled
when switching on multiattachment.</p>
<p>Further down in the code I see that replication and multiattach
are mutually exclusive.</p>
<p>Is there some documentation about the Ceph multiattach feature,
even an email thread?</p>
<p>Thanks,</p>
<p>Bernd<br>
<code class="gmail-m_-6402079754429978577py gmail-m_-6402079754429978577hljs gmail-m_-6402079754429978577python"></code></p>
</div>
</blockquote></div>