Unable to add a host to a pool

Kajetan321

I'm trying to create my first pool with more than one host. When I try to add host to pool I get this in the logs:

POOL_JOINING_EXTERNAL_AUTH_MISMATCH()

This is a XenServer/XCP-ng error

All hosts have all patches applied. I'm running xo-server 5.98.1 built from source, Xen Orchestra, commit 82452.

Any ideas?

tjkreidl

@Kajetan321 Check the BIOS versions and settings to make sure they are the same; mismatches can in some cases cause CPU masking differences.

Kajetan321

@tjkreidl Umm, I didn't realize that all hosts in a pool need to run on identical hardware. Is this the case? My two hosts in question have different CPUs. Is that a non starter?

tjkreidl

@Kajetan321 They have to be pretty close! Similar to XenServer, the CPU masks must be pretty close for things to work, and never Intel + AMD hosts. See for example the XCP-ng documentation on heterogeneous pools or for example: https://support.citrix.com/article/CTX127059/understanding-heterogeneous-cpu-pooling-in-xenserver

Kajetan321

@tjkreidl Thanks, reading it now.

olivierlambert

This message means you have different ways to authenticate. If you use AD integration, please disable it.

Kajetan321

Well, that deteriorated quickly. After disabling the LDAP plugin I was finally able to migrate the VM, but only when it was powered off.

The problem is now the VM will not start on this new host and it will not migrate back to the host it was on before.

I used the my backups to restore the VM in question on to it's original host. When I powered it up, unfortunately VM did not complete booting, something about the clock has gone backwards. After restarting the VM however, everything is working as it should.

I suspect this system is too old, it's an Intel(R) Core(TM) i5-4570 CPU @ 3.20GHz, I just set it up for experimenting. It also only has 8GB of RAM.

tjkreidl

@Kajetan321 I'm guessing there is an incompatibility issue. Again, the CPUs have to be quite similar for this to work and the BIOD settings have to also match closely. Sorry for your hassles, but try finding a more compatible CPU. Citrix at least used to have a compatibility list though it's not updated as often as one would want. See also this article for some useful info, as old as it is. Some of these utility may no longer exist, alas.
https://support.citrix.com/article/CTX127059/understanding-heterogeneous-cpu-pooling-in-xenserver

olivierlambert

Sadly, it's hard to know what happened without getting the errors you had (eg when you tell: "VM will not start" is very vague).