TOPIC:

I don't think that is possible. The master UUID is read by the slave when it connects to the master. On the master, that value is read-only and can not be changed.

Are you certain that the two hosts you have provided screenshots for are actually in the same pool? Even the pool-uuid is different. Both hosts are reporting to be part of a pool, but not with eachother.
Please confirm whether you have other hosts on the network that could have been mixed up..

Hi Salvatore,
Thanks for you prompt reply again.
If I look to the screenshots, the Pool UUID's are the same, so why do you think they are different?
Both machines are in the same pool (and were working perfectly until we changed the network card)
To my knowledge those 2 machines are the only XenServers in our VLAN and if I check with Xen Center, they are still in the same pool.

One thing I remember from last week, I had to change the interface from xapi7 to xapi0 to get iscsi back to work, could this be of influence?

You are correct about the pool-uuid.. the image resolution is not good and it was hard to read.

Changing NIC configuration could have contributed to this. Lets rule out a few things by bypassing ha-cfg.

1) Ensure the pool-uuid is the same on each host
2) Try fetching HA status directly from the DB from each host.. The result should be the same (true or false). The result comes from the DB on the pool master. Meaning the master will locally connect to API and the slave will connect to the master via API to request the same data from the same DB.
3) Confirm the host UUIDs
Lets see if this provides any more clues. Try each command on both hosts. The results should be identical in each case.

Hi Salvatore,
1) The pool list xe pool-list --minimal, shows the exact same UUID: 1e461c89-52da-6ac5-9673-79a126d1d16b
2) The status of xe pool-parameter get gives for both systems false (even if I set one to HA-cfg enabled)
3) The host list is exactly the same

So no additional clues

It's hard to tell from the image, but the master's host-uuid looks different than the master-uuid in the output of ha-cfg for the master. These 2 values should be the same.

Can you run the following 2 commands on the master and let me know whether they match:

Hi Salvatore,
Sorry I didn't com back to you on Friday, my weekend in Europe started already
I get the following info:
[root@aeudcimpnlhyp2 ~]# xe host-list hostname=$(hostname) --minimal
36f63b61-7f8c-441f-8c6e-d3559c5d8832
[root@aeudcimpnlhyp2 ~]# xe pool-param-get uuid=$(xe pool-list --minimal) param-name=master
36f63b61-7f8c-441f-8c6e-d3559c5d8832

And on the other:

[root@aeudcimpnlhyp1 ~]# xe host-list hostname=$(hostname) --minimal
3afdf3d7-cf15-4a2b-86ed-b60fc8c4d12b
[root@aeudcimpnlhyp1 ~]# xe pool-param-get uuid=$(xe pool-list --minimal) param-name=master
36f63b61-7f8c-441f-8c6e-d3559c5d8832

So the master UUID are matching, with those commands
However, the Master UUID of the HYP2, lis different when I run ha-cfg status: 3afdf3d7-cf15-4a2b-86ed-b60fc8c4d12b

The master UUID of the HYP1, dispalyed in the ha-cfg status is correct : 36f63b61-7f8c-441f-8c6e-d3559c5d8832

Hans