<div dir="ltr"><div class="gmail_extra"><div class="gmail_quote">On Wed, Nov 29, 2017 at 6:49 PM, Demeter Tibor <span dir="ltr"><<a href="mailto:tdemeter@itsmart.hu" target="_blank">tdemeter@itsmart.hu</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">Hi,<br>
<br>
Yes, I understand what do you talk about. It isn't too safe..:(<br>
We have terrabytes under that VM.<br>
I could make a downtime at most for eight hours (maybe), but meanwhile I have to copy 3 TB of vdisks. Firstly I need export (with a gigabit nic) to export domain, and back under 10gbe nic.<br>
I don't know how is enough this.<br>
<br>
Thanks<br>
<span class="gmail-HOEnZb"><font color="#888888"><br>
Tibor</font></span></blockquote><div><br></div><div>Hi Tibor,</div><div>I'm in shortage of time these days, but I have to admit your problem was so intriguing that I couldn't resist and I decided to try and reproduce it.</div><div>All happened on my laptop with Fedora 26 (time to upgrade? not enough time... ;-)</div><div><br></div><div>So this is the test environment of all vms inside virt-manager:</div><div><br></div><div>1) Create 3.5.6 environment</div><div><br></div><div>- CentOS 6.6 VM (this was the iso I had at hand...) with hostname c6engine35 where I installed oVirt 3.5.6 as engine</div><div>- CentOS 6.6 VM with hostname c6rhv35 (sorry for the rhv in the name but these weeks I'm also working on it so it came out quite naturally...) were I installed the Hypervisor of 3.5.6 repo</div><div><br></div><div>I created a local DC on top of a directory of the hypervisor (/ldomain)</div><div>I created a CentOS 6.6 VM in this storage domain with a 4Gb disk</div><div><br></div><div>2) Detach the local domain from DC</div><div><br></div><div>HERE YOUR THEORETICAL DOWNTIME BEGINS</div><div><br></div><div>To do so I powered off the test VM and created a fake further local domain based on another directory of c6rhv35</div><div>Then put into maintenance the local domain to be imported in 4.1</div><div>The fake local domain becomes the master.</div><div>Detach the local domain.</div><div><br></div><div><br></div><div>3) Create 4.1.7 environment (in your case it is already there..)</div><div><div>- CentOS 7.4 VM with hostname c7engine41 where I installed oVirt 4.1.7 as engine</div><div>- CentOS 7.4 VM with hostname c7rhv41 were I installed the Hypervisor of 4.1.7 repo</div></div><div> </div><div>I created a shared DC NFSDC with a cluster NFSCL</div><div>To speed things I exported a directory from the engine and used it to create an NFS storage domain (DATANFS) for the 4.1 host and activated it</div><div><br></div><div>4) Shutdown 3.5 environment and start/configure the 3.5 hypervisor to export its previously local storage domain directory</div><div><br></div><div>Start c6rhv35 in single user mode</div><div>chkconfig service_name off</div><div><br></div><div>for this service_name:</div><div>ebtables ip6tables iptables libvirt-guests libvirtd momd numad sanlock supervdsmd vdsmd wdmd</div><div><br></div><div>reboot</div><div>create an entry in /etc/exports</div><div><br></div><div><div>/ldomain c7rhv41.localdomain.local(rw)</div></div><div><br></div><div>service nfs start</div><div><br></div><div>set up accordingly the /etc/hosts of the servers involved so that all know all...</div><div><br></div><div>5) import domain in 4.1</div><div>Select Storage -> Import domain and put </div><div><br></div><div>c6rhv35.localdomain.local:/ldomain <br></div><div><br></div><div>You will get a warning about it being already part of another DC:</div><div><a href="https://drive.google.com/file/d/1HjFZhW6fCkasPak0jQH5k49Bdsg1NLSN/view?usp=sharing">https://drive.google.com/file/d/1HjFZhW6fCkasPak0jQH5k49Bdsg1NLSN/view?usp=sharing</a><br></div><div><br></div><div>Approve operation and you arrive here:</div><div><a href="https://drive.google.com/file/d/10d1ea0TbPCZhoaAf7br5IVqnvZx0LzSu/view?usp=sharing">https://drive.google.com/file/d/10d1ea0TbPCZhoaAf7br5IVqnvZx0LzSu/view?usp=sharing</a><br></div><div><br></div><div>Activate the domain and you arrive here:</div><div><a href="https://drive.google.com/file/d/1-4sMfVVj5WyaglPI8zhWUsdJqkVkxzAT/view?usp=sharing">https://drive.google.com/file/d/1-4sMfVVj5WyaglPI8zhWUsdJqkVkxzAT/view?usp=sharing</a><br></div><div><br></div><div>Now you can proceed importing your VMs; in my case only the testvm</div><div>Select he imported storage domain and then the "VM Import" tab; select the VM and "Import":</div><div><br></div><div><a href="https://drive.google.com/file/d/18yjPvoHjTw6mOhUrlHJ2RpsdPph4qBxL/view?usp=sharing">https://drive.google.com/file/d/18yjPvoHjTw6mOhUrlHJ2RpsdPph4qBxL/view?usp=sharing</a><br></div><div><br></div><div><a href="https://drive.google.com/file/d/1CrCzVUYC3vI4aQ2ly83b3uAQ3QQh1xhm/view?usp=sharing">https://drive.google.com/file/d/1CrCzVUYC3vI4aQ2ly83b3uAQ3QQh1xhm/view?usp=sharing</a><br></div><div><br></div><div>Note that it is an immediate operation, and not depending on the size of the disks of the VM itself</div><div>At the end you get your VM imported; here details:</div><div><br></div><div><a href="https://drive.google.com/file/d/1W00TpIKAQ7cWUit_tLIQkm30wj5j56AN/view?usp=sharing">https://drive.google.com/file/d/1W00TpIKAQ7cWUit_tLIQkm30wj5j56AN/view?usp=sharing</a><br></div><div><a href="https://drive.google.com/file/d/1qq7sZV2vwapRRdjbi21Z43OOBM0m2NuY/view?usp=sharing">https://drive.google.com/file/d/1qq7sZV2vwapRRdjbi21Z43OOBM0m2NuY/view?usp=sharing</a><br></div><div><br></div><div>While you import, you can then gradually start your VMs, so that your downtime becomes partial and not total</div><div><a href="https://drive.google.com/file/d/1kwrzSJBXISC0wBTtZIpdh3yJdA0g3G0A/view?usp=sharing">https://drive.google.com/file/d/1kwrzSJBXISC0wBTtZIpdh3yJdA0g3G0A/view?usp=sharing</a><br></div><div><br></div><div>When you have started all your imported VMs, YOUR THEORETICAL DOWNTIME ENDS</div><div><br></div><div>Your VMS are now running on your old local storage, exported from your old 3.5 host to your new 4.1 hosts via NFS</div><div><br></div><div>You can now execute live storage migration of your disks one by one to the desired 4.1 storage domain:</div><div><a href="https://drive.google.com/file/d/1p6OOgDBbOFFGgy3uuWT-V8VnCMaxk4iP/view?usp=sharing">https://drive.google.com/file/d/1p6OOgDBbOFFGgy3uuWT-V8VnCMaxk4iP/view?usp=sharing</a><br></div><div><br></div><div>and at the end of the move</div><div><a href="https://drive.google.com/file/d/1dUuKQQxI0r4Bhz-N0TmRcsnjwQl1bwU6/view?usp=sharing">https://drive.google.com/file/d/1dUuKQQxI0r4Bhz-N0TmRcsnjwQl1bwU6/view?usp=sharing</a><br></div><div><br></div><div>Obviously there are many caveats in a real environment such as:</div><div><br></div><div>- actual oVirt origin and target version could differ from mine and behavior be different</div><div>- network visibility between the two oVirt environments</div><div>- layout of the logical networks of the two oVirt environments: when you import you could need to change logical network and have conflicting MACS: </div><div>in my test scenario it was all on ovirtmgmt with the same macs range</div><div>- live storage migration of TB of disks.. not tested yet (by me at least)....</div><div>- other things that don't come to mind right now....</div><div><br></div><div>HIH,</div><div>Gianluca</div><div><br></div><div><br></div><div><br></div><div><br></div><div><br></div><div><br></div><div><br></div><div><br></div><div> </div><div><br></div><div><br></div><div><br></div><div><br></div><div><br></div><div> </div></div></div></div>