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cite="mid:CAM_m6wrApNwstu06pTMEjVWEg8doc2-eShCOTxOi_pgOMnfLwg@mail.gmail.com">
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<div>Good Day </div>
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<div>From documentation we are able to understand that we can
configure multiple backends for cinder (Ceph ,External Storage
device or NFS etc)</div>
<div>Is there any way we can choose the backend while instance
launching .Say instance1 backend should be from an external
storage device like EMC and instance2 to launch and have
backend volume from ceph .Can this be achieved using cinder
availability zone implementation or any other way?<br>
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<div>I have gone through below link (<b>section Configure Block
Storage scheduler multi back end)</b></div>
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<div><a
href="https://docs.openstack.org/cinder/latest/admin/blockstorage-multi-backend.html"
moz-do-not-send="true">https://docs.openstack.org/cinder/latest/admin/blockstorage-multi-backend.html</a><br>
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<div> Suggestions please .. </div>
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<div>Regards,</div>
<div>Deepa K R <br>
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</blockquote>
<p>Hi Deepa,</p>
<p>Backend selection is controlled by the scheduler, with the end
user being able to choose different volume types configured by the
administrator to tell the scheduler what characteristics are
needed for the selected storage.</p>
<p>The Volume Type section in the Multibackend docs briefly describe
some of this:</p>
<p><a class="moz-txt-link-freetext" href="https://docs.openstack.org/cinder/latest/admin/blockstorage-multi-backend.html#volume-type">https://docs.openstack.org/cinder/latest/admin/blockstorage-multi-backend.html#volume-type</a></p>
<p>These volume types can be configured with extra specs the
explicitly declare a specific backend name to use for creating
volumes of that type, or it can contain extra specs that just
define other properties (such as just stating the protocol needs
to be iscsi) and the scheduler will use those to decide where to
place the volume.</p>
<p>Some description of defining availability zones in extra specs
(which I'm seeing could really use some updates) can be found
here:</p>
<p><a class="moz-txt-link-freetext" href="https://docs.openstack.org/cinder/latest/admin/blockstorage-availability-zone-type.html">https://docs.openstack.org/cinder/latest/admin/blockstorage-availability-zone-type.html</a><br>
</p>
<p>From the command line, you can also explicitly state which
availability zone you want the volume created in. See bullets 2
and 3 here:</p>
<p><a class="moz-txt-link-freetext" href="https://docs.openstack.org/cinder/latest/cli/cli-manage-volumes.html#create-a-volume">https://docs.openstack.org/cinder/latest/cli/cli-manage-volumes.html#create-a-volume</a></p>
<p>Good luck!</p>
<p>Sean<br>
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