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<p class="MsoNormal"><span style="color:#1F497D">Hi All,<o:p></o:p></span></p>
<p class="MsoNormal"><span style="color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="color:#1F497D">Is there a way to find in cinder how many instances are attached to a volume?<o:p></o:p></span></p>
<p class="MsoNormal"><span style="color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="color:#1F497D">Thanks & Regards,<o:p></o:p></span></p>
<p class="MsoNormal"><span style="color:#1F497D">Sneha Rai<o:p></o:p></span></p>
<p class="MsoNormal"><span style="color:#1F497D"><o:p> </o:p></span></p>
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<p class="MsoNormal"><b>From:</b> RAI, SNEHA <br>
<b>Sent:</b> Monday, July 1, 2019 5:26 PM<br>
<b>To:</b> openstack-dev@lists.openstack.org<br>
<b>Subject:</b> HPE 3PAR Cinder driver-Multiattach: Fails to detach second instance from volume<o:p></o:p></p>
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<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Hi Team,<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">There is a bug on 3PAR Cinder driver <a href="https://bugs.launchpad.net/cinder/+bug/1834660">
https://bugs.launchpad.net/cinder/+bug/1834660</a>.<o:p></o:p></p>
<p class="MsoNormal">I am able to attach multiple instances to 3PAR volume but only the first instance gets detached successfully.<o:p></o:p></p>
<p class="MsoNormal">For the second instance, volume goes into detaching status due to “Host does not exist” error.<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">What is happening here is, the first detach call invokes <span style="font-size:9.0pt;font-family:Consolas;color:#333333;background:white">
_delete_3par_host() </span>which removes the compute host entry from 3PAR which ideally should be done only when the last instance is to be detached.<o:p></o:p></p>
<p class="MsoNormal">It would be great if someone could help me understand if this needs to be handled in driver code or nova would internally take care of it.<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Code changes done to support multiattach-<a href="https://review.opendev.org/#/c/659443">https://review.opendev.org/#/c/659443</a><o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Thanks & Regards,<o:p></o:p></p>
<p class="MsoNormal">Sneha Rai<o:p></o:p></p>
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