Unknown error - this pool is already connected

rkelley

@darkbeldin Here are the steps I used:

Install 3 node cluster with XCP-NG 8.2
Install XOA
Reconfigure mgmt interface - lose all access to XCP-NG cluster.
Try to force-remove (eject) nodes from cluster. Unsuccessful.
Remove nodes from XOA
Reinstall XCP-NG on nodes - without HA (nodes are standalone)
Add node-1 to XOA; good
Add node-2 to XOA - Error: This pool is already connected
Add node-3 to XOA - Error: This pool is already connected

It seems XOA is not cleaning up some internal data structures if it sees the new standalone nodes as part of an old cluster. This seems like a bug to me.

Danp

@rkelley Have you tried restarting xo-server or rebooting the XO VM?

rkelley

@danp Yes, just rebooted XOA. Problem still exists.

abrehmc

@rkelley said in Unknown error - this pool is already connected:

@danp Yes, just rebooted XOA. Problem still exists.

We have the exact same problem, all slave servers have that error also after reboot.
Is slave servers supposed to be here in the first place? The XOA has all hosts listed "Home/Hosts) and by "pool" I guess it means "Master".
I had one missing slave server, but adding it just gave the error.
Can we delete all servers that does not have a pool listed by them under "Settings/Servers"?

olivierlambert

What? You shouldn't have any slave in Settings/server, just the IP of the pool master, that's it.

abrehmc

@olivierlambert
So, they are safe to delete?

Darkbeldin

@abrehmc More than safe to delete, you need to delete them.

olivierlambert

Yes, you are not meant to add slaves in there.

abrehmc

@olivierlambert
Thanks guys

paco

This is an old thread, but I ran into this myself recently. While there is a link to deleting the entire XO configuration, I think I fixed it with a less drastic solution. Remember: I'm just a random dude on the internet posting dangerous commands to try. It worked for me, but your mileage might vary.

I run Xen Orchestra in a container (Xen Orchestra, commit e8733 at the time of writing). So I got a command line in the container with:

docker exec -it xoa bash

Then I ran redis-cli to get a redis command prompt. I typed KEYS * to get a list of keys. One key I saw was: 7) xo:server_host:172.30.0.214". That's the IP of the host I was trying to join (the master of a single-host pool). So I ran:

del xo:server_host:172.30.0.214

Then I restarted my container with docker restart xoa. After that, I was able to successfully add the host to Xen Orchestra.

Maybe this will help someone else. It got me working again.