<div dir="ltr"><div class="gmail_default" style="font-family:monospace,monospace"><br></div><div class="gmail_extra"><br><div class="gmail_quote">On Mon, Nov 9, 2015 at 8:15 AM, Zhenyu Zheng <span dir="ltr"><<a href="mailto:zhengzhenyulixi@gmail.com" target="_blank">zhengzhenyulixi@gmail.com</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div dir="ltr">Hi, thanks all for replying, sorry I might be a bit unclear. <div><br></div><div>We have user demands that we only change the root device of an volume-backed instance for upper layer services. It's not cloudy but it is quite common. And changing OS is another demand that sort of related to this.</div></div></blockquote><div> </div><div><div class="gmail_default" style="font-family:monospace,monospace;display:inline">I'm not sure I agree that it's "common", not to mention "common" in what context/perspective? Regardless I don't think the complexity and risk that something like this introduces is worth the questionable value that it gives. No offense perhaps I'm still not quite getting the use case. It's possible I don't know what you mean by "upper layer services".</div></div><div><div class="gmail_default" style="font-family:monospace,monospace;display:inline"><br></div></div><div><div class="gmail_default" style="font-family:monospace,monospace;display:inline">By the way, when you say things like "it's not cloudy" I unfortunately automatically think "isn't OpenStack a Cloud Platform"?</div></div><div><div class="gmail_default" style="font-family:monospace,monospace;display:inline"><br></div></div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div dir="ltr"><div><br></div><div>Cinder supports live-backup volume, but not support live-restore a volume.</div></div></blockquote><div> </div><div><div class="gmail_default" style="font-family:monospace,monospace;display:inline">Nope, no plans at all. This would be a pretty involved task given that the backup in cinder is just dd of blocks at the raw device level. It is however certainly possible to restore to a "new" volume and then swap attachments, but then that goes against your desire of keeping UUID's, and it doesn't work for Cinder backed Instances, so I guess that suggestion is out as well. </div> </div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div dir="ltr"><div><br></div><div>Are we planning to support this kind of action?</div></div></blockquote><div><br></div><div><div class="gmail_default" style="font-family:monospace,monospace;display:inline">Nope, no plans at all. I'd also argue that we rather than compromising and doing things that are "not cloudy" we should be pushing harder on being cloudy and the strengths that come from it. We should be good at one paradigm, not bad at all of them.</div></div><div><div class="gmail_default" style="font-family:monospace,monospace;display:inline"></div></div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div dir="ltr"><div><br></div><div>Yours,</div><div>Zheng</div></div><div class="gmail_extra"><br><div class="gmail_quote"><div><div class="h5">On Mon, Nov 9, 2015 at 8:24 PM, Duncan Thomas <span dir="ltr"><<a href="mailto:duncan.thomas@gmail.com" target="_blank">duncan.thomas@gmail.com</a>></span> wrote:<br></div></div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div><div class="h5"><div dir="ltr"><div class="gmail_extra"><div class="gmail_quote"><span>On 9 November 2015 at 09:04, Zhenyu Zheng <span dir="ltr"><<a href="mailto:zhengzhenyulixi@gmail.com" target="_blank">zhengzhenyulixi@gmail.com</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div dir="ltr"><div> And Nova side also doesn't support detaching root device, that means we cannot performing volume backup/restore from cinder side, because those actions needs the volume in "available" status. </div><div><br></div></div></blockquote><div><br></div><div><br></div></span><div>It might be of interest to note that volume snapshots have always worked on attached volumes, and as of liberty, the backup operation now supports a --force=True option that does a backup of a live volume (via an internal snapshot, so it should be crash consistent) </div></div><span><font color="#888888"><br clear="all"><div><br></div>-- <br><div><div dir="ltr"><div>-- <br>Duncan Thomas</div></div></div>
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