<div dir="ltr">Hi Chenzongliang,<div><br></div><div>I still don't understand what is difference between proposed feature and 'restore volume from snapshot'? Could you please explain it?</div></div><div class="gmail_extra"><br clear="all"><div><div class="gmail_signature"><div dir="ltr"><div>Regards,<br>Ivan Kolodyazhny,<br><a href="http://blog.e0ne.info/" target="_blank">http://blog.e0ne.info/</a></div></div></div></div>
<br><div class="gmail_quote">On Thu, Apr 7, 2016 at 12:00 PM, Chenzongliang <span dir="ltr"><<a href="mailto:chenzongliang@huawei.com" target="_blank">chenzongliang@huawei.com</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
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<p class="MsoNormal"><span lang="EN-US" style="font-size:10.5pt;font-family:"Calibri","sans-serif";color:#44546a">Dear Cruz:<u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:10.5pt;font-family:"Calibri","sans-serif";color:#44546a"><u></u> <u></u></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:10.5pt;font-family:"Calibri","sans-serif";color:#44546a"> Thanks for you kind support, I will review the previous spec according to the following links. May be more user scenario we should
considered,such as backup,create volume from snapshot,consistency group and etc,we will spend some time to gather
<u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:10.5pt;font-family:"Calibri","sans-serif";color:#44546a">the user's scenarios and determin what to do next step.
<u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:10.5pt;font-family:"Calibri","sans-serif";color:#44546a"><u></u> <u></u></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:10.5pt;font-family:"Calibri","sans-serif";color:#44546a">Sincerely,<u></u><u></u></span></p>
<p class="MsoNormal" style="text-align:start;word-spacing:0px">
<span lang="EN-US" style="font-size:10.5pt;font-family:"Calibri","sans-serif";color:#44546a">zongliang chen<u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:10.5pt;font-family:"Calibri","sans-serif";color:#44546a"><u></u> <u></u></span></p>
<div style="border:none;border-top:solid #b5c4df 1.0pt;padding:3.0pt 0cm 0cm 0cm">
<p class="MsoNormal"><b><span style="font-size:10.0pt">发件人<span lang="EN-US">:</span></span></b><span lang="EN-US" style="font-size:10.0pt"> Erlon Cruz [mailto:<a href="mailto:sombrafam@gmail.com" target="_blank">sombrafam@gmail.com</a>]
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</span><b><span style="font-size:10.0pt">发送时间<span lang="EN-US">:</span></span></b><span lang="EN-US" style="font-size:10.0pt"> 2016</span><span style="font-size:10.0pt">年<span lang="EN-US">4</span>月<span lang="EN-US">5</span>日<span lang="EN-US"> 2:50<br>
</span><b>收件人<span lang="EN-US">:</span></b><span lang="EN-US"> OpenStack Development Mailing List (not for usage questions)<br>
</span><b>抄送<span lang="EN-US">:</span></b><span lang="EN-US"> Zhangli (ISSP); Shenhong (C)<br>
</span><b>主题<span lang="EN-US">:</span></b><span lang="EN-US"> Re: [openstack-dev] [Cinder] About snapshot Rollback?<u></u><u></u></span></span></p>
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<p class="MsoNormal"><span lang="EN-US"><u></u> <u></u></span></p>
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<p class="MsoNormal"><span lang="EN-US">Hi Chen,<u></u><u></u></span></p>
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<p class="MsoNormal"><span lang="EN-US"><u></u> <u></u></span></p>
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<p class="MsoNormal"><span lang="EN-US">Not sure if I got you right but I brought this topic in #openstack-cinder some days ago. The idea is to be able to rollback a snapshot in Cinder. Today what is possible to do is to create a volume from a snapshot. From
the user point of view, this is not ideal, as there are several cases, if not the majority of, that the purpose of the snapshot is to revert to a desired state, and not keep the original volume. For some backends, keeping the original volume means space consumption.
This space problem becomes bold when we think about consistency groups. For consistency groups, some backends might have to copy an entire filesystem for each snapshot, consuming space and time. So, I think it would be desired to have the ability to revert
snapshots.<u></u><u></u></span></p>
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<p class="MsoNormal"><span lang="EN-US"><u></u> <u></u></span></p>
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<p class="MsoNormal"><span lang="EN-US">I know there have been efforts in the past[1] to implement that, but for some reason the work was stopped. If you want to retake the effort please create a spec[2] sol everybody can provide feedback. <u></u><u></u></span></p>
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<p class="MsoNormal"><span lang="EN-US"><u></u> <u></u></span></p>
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<p class="MsoNormal"><span lang="EN-US">Erlon<u></u><u></u></span></p>
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<p class="MsoNormal"><span lang="EN-US"><u></u> <u></u></span></p>
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<p class="MsoNormal"><span lang="EN-US"><u></u> <u></u></span></p>
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<p class="MsoNormal"><span lang="EN-US">[1] <a href="https://blueprints.launchpad.net/cinder/+spec/cinder-volume-rollback-snapshot" target="_blank">
https://blueprints.launchpad.net/cinder/+spec/cinder-volume-rollback-snapshot</a><u></u><u></u></span></p>
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<p class="MsoNormal"><span lang="EN-US">[2] <a href="https://github.com/openstack/cinder-specs" target="_blank">https://github.com/openstack/cinder-specs</a><u></u><u></u></span></p>
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<p class="MsoNormal"><span lang="EN-US"><u></u> <u></u></span></p>
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<p class="MsoNormal"><span lang="EN-US">On Thu, Mar 24, 2016 at 6:09 AM, Chenzongliang <<a href="mailto:chenzongliang@huawei.com" target="_blank">chenzongliang@huawei.com</a>> wrote:<u></u><u></u></span></p>
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<p class="MsoNormal"><span lang="EN-US">Hi all:<u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-US"> We are condering add a fucntion rollback_snapshot when we use backup. In the end user's scenario. If a vm fails, we hope that we can use snapshot to to recovery
the volume's data. <u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-US"> Beacuse it can quickly recovery our vm. But if we use the remote data to recovery. We will spend more time.<u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-US"> But i'm not sure if the data was recoveried from the backend. whether the host need to rescan the volumes? At the same time. If a volume have been extended,
whether it can be roolback? <u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-US">
<u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-US"> I want to know whether the topic have been discussed or have other recommendations to us?<u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-US">
<u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-US"> Thanks<u></u><u></u></span></p>
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<p class="MsoNormal" style="margin-bottom:12.0pt"><span lang="EN-US"><br>
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