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<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">Hi Matthew,<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">Doesn’t just setting “enable_new_services=False” give you what you want ?
<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">We run this on all of our servers so that any newly installed systems can be checked before they are allowed to start hosting Instances. Couple that with
a change we’ve been trying to get through for a while now to add a short text field to the services to capture what they are disabled (https://review.openstack.org/#/c/10877/ ) and you could just set the reason field to “Spare” on the ones you decide not
to enable.<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">Cheers,<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">Phil<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><b><span lang="EN-US" style="font-size:10.0pt;font-family:"Tahoma","sans-serif"">From:</span></b><span lang="EN-US" style="font-size:10.0pt;font-family:"Tahoma","sans-serif""> Matthew Sherborne [mailto:msherborne@gmail.com]
<br>
<b>Sent:</b> 22 March 2013 16:28<br>
<b>To:</b> OpenStack Development Mailing List<br>
<b>Subject:</b> [openstack-dev] blueprint for 'spare-hosts'<o:p></o:p></span></p>
<p class="MsoNormal"><o:p> </o:p></p>
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<p class="MsoNormal" style="margin-bottom:12.0pt">All comments appreciated.<br>
<br>
<a href="https://blueprints.launchpad.net/nova/+spec/spare-hosts">https://blueprints.launchpad.net/nova/+spec/spare-hosts</a><o:p></o:p></p>
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<p class="MsoNormal" style="margin-bottom:12.0pt">In summary, when one sets up a nova install, they can set some of the machines to spare.<o:p></o:p></p>
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<p class="MsoNormal" style="margin-bottom:12.0pt">Spare means disabled plus the guarantee that there are no customer vms running on there.<o:p></o:p></p>
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<p class="MsoNormal">It differs from maintenance mode in that setting a spare that has VMs on it, will just fail, rather than cause a migration.<o:p></o:p></p>
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<p class="MsoNormal"><o:p> </o:p></p>
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<p class="MsoNormal" style="margin-bottom:12.0pt">Spare machines can be used for quick chassis swaps or can be enabled to receive an emergency migration, or when an end user needs more space than was initially planned.<br>
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Having 'spare' machines in your install a useful safety buffer to let you know when to start adding more.<o:p></o:p></p>
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<p class="MsoNormal"><a href="https://wiki.openstack.org/wiki/Blueprint-spare-hosts#Possible_later_additions">https://wiki.openstack.org/wiki/Blueprint-spare-hosts#Possible_later_additions</a><o:p></o:p></p>
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----<o:p></o:p></p>
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<p class="MsoNormal" style="margin-bottom:12.0pt">Please comment on implementation ideas, additional features, and perceived usefulness.<o:p></o:p></p>
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<p class="MsoNormal">Many Thanks,<o:p></o:p></p>
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<p class="MsoNormal">Matthew Sherborne<o:p></o:p></p>
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