Migration from Cloudmin to XCP-NG

olivierlambert

Convert your PV guest to HVM
There's a Python script to send them to XCP-ng (see https://xcp-ng.org/docs/migratetoxcpng.html#from-xen-on-linux)

gskger

@olivierlambert I think the OP tried using the Phyton script, but the link in the documentation is broken. A quick search gives no good results, so hopefully someone on the forum has the script available.

olivierlambert

Ah indeed, the link is now dead Let me check if I can find it again

edit: ah I know why. Xen community manager is migrating to Hugo. Let me ping him to get back that file!

olivierlambert

In the meantime: https://gist.github.com/olivierlambert/0182f1cee63568edffd3b71b497b2eff

I'll change the link in the doc.

olivierlambert

The doc is now updated with the right link: https://xcp-ng.org/docs/migratetoxcpng.html#from-xen-on-linux

Thanks for the feedback!

PadrinoGT

Wow!

Thank you for the response and the feedback!

Let me run with this during the day.

Is it 100% required to convert the PV to HVM before migrating?

Is it possible to convert after its been migrated or can I not just run PV on XCP-NG with some prep work on the Dom0?

olivierlambert

You can convert after But don't forget to do it, PV is deprecated anyway.

PadrinoGT

So just an update from my side.

The scripted migration works like a charm!

The VM starts up to this point.

[ 1.866672] xcpngtest kernel: blkfront: xvda: barrier: enabled; persistent gr
ants: disabled; indirect descriptors: disabled;
[ 193.898756] xcpngtest dracut-initqueue[118]: Warning: dracut-initqueue timeout - starting timeout scripts
[ 194.434593] xcpngtest dracut-initqueue[118]: Warning: dracut-initqueue timeout - starting timeout scripts
[ 194.970868] xcpngtest dracut-initqueue[118]: Warning: dracut-initqueue timeout - starting timeout scripts
[ 194.971501] xcpngtest dracut-initqueue[118]: Warning: Could not boot.
[ 194.972159] xcpngtest dracut-initqueue[118]: Warning: /dev/xvda1 does not exist
[ 195.003944] xcpngtest systemd[1]: Starting Setup Virtual Console...
[ 195.012622] xcpngtest systemd[1]: Started Setup Virtual Console.
[ 195.014922] xcpngtest systemd[1]: Starting Dracut Emergency Shell...

It then drops out to the Dracut Emergency shell.

My suspicion is that the server is presenting xvda instead of xvda1 to the VM.

Just working on that now.

PadrinoGT

My suspicion was correct.

If I edit the grub config to say the root is at /dev/xvda instead of /dev/xvda1 the vm boots succesfully in XCP-NG.

Is there a way to rather edit XCP-Ng to use xvda1 instead of my having to edit the grub file before migration?

olivierlambert

None I'm aware of, the device path is by default on xvda and this is the "right one" (Grub is on the whole device boot sector, not on a partition)

PadrinoGT

Hi.

So I found an interesting thing on the Cloudmin side.

I am able to change the grub config on the VM before I migrate, which then allows the boot to work on XCP-NG.

How ever my main concern was if for some reason I need to roll back I won't be able to boot the VM up to the point where I can change the grub config.

But in Cloudmin there is an option for me to change the device address that will then be able to match the grub config.

Thank you again for all your assistance!

I am very excited to pitch the migration path to my management this week!