<div dir="ltr">Apologies about missing this question earlier, here's a thread on openstack-operators where this was covered:<br><a href="http://lists.openstack.org/pipermail/openstack-operators/2015-May/007142.html">http://lists.openstack.org/pipermail/openstack-operators/2015-May/007142.html</a><br></div><br><div class="gmail_quote"><div dir="ltr">On Wed, May 13, 2015 at 2:24 PM Forrest Flagg <<a href="mailto:fostro.flagg@gmail.com">fostro.flagg@gmail.com</a>> wrote:<br></div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div dir="ltr">Hi,<div><br></div><div>Looking at the documentation for Fuel 6.0 [1] and it's stated that when using Ceph one should disable qcow2 so that images are stored in raw format.  This is due to the fact that Ceph includes its own mechanisms for copy-on-write and snapshots.  According to [2] this is true only when using a BTRFS file system, but in Fuel 6.0 Ceph uses XFS which doesn't provide this functionality.  Also, [2] recommends not using BTRFS for production as it isn't considered fully mature.  In addition, Fuel 6.0 [3] states that OpenStack with raw images doesn't support snapshotting.</div><div><br></div><div>Given this, why does Fuel suggest not using qcow2 with Ceph?  How can Ceph be useful if snapshotting isn't an option with raw images and qcow2 isn't recommended?  Are there other factors to take into consideration that I'm missing?</div><div><br></div><div>[1]  <a href="https://docs.mirantis.com/openstack/fuel/fuel-6.0/terminology.html#qcow2" target="_blank">https://docs.mirantis.com/openstack/fuel/fuel-6.0/terminology.html#qcow2</a></div><div>[2]  <a href="http://ceph.com/docs/master/rados/configuration/filesystem-recommendations/" target="_blank">http://ceph.com/docs/master/rados/configuration/filesystem-recommendations/</a></div><div>[3]  <a href="https://docs.mirantis.com/openstack/fuel/fuel-6.0/user-guide.html#qcow-format-ug" target="_blank">https://docs.mirantis.com/openstack/fuel/fuel-6.0/user-guide.html#qcow-format-ug</a></div><div><br></div><div>Forrest</div><div><br></div></div>
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