Good moaning...

The solution was pretty simple: a toolstack restart on the master (xcp83) did get all back on track and it now allows me to move the systems with a simple shutdown/start.

@Danp Yes, they are all 'empty':

xe vm-cd-list --multiple | grep -i false

doesn't give any output.

@Danp Thanks for looking into this...

Restart: Yes, Pool Master was restarted after applying the XCP patches
VM start: Yes, I'm trying to start the VMs on the master (also, it would not allow me to start VMs on the slaves with XenServer on it during the migration phase)
Upgrade Path: Yes, vrom XS 7.1.2 to XCP 8.3

Regarding the VM_HOST_INCOMPATIBLE_VERSION: I saw those, too, but cannot think of anything obvious, as the VMs which I was able to start on the Master were of the same kind (WinSrv2019, Ubuntu Server, Win10). Of course, there might be slight differences in the metadata, but I've compared two WinSrv2019 and they are pretty close. Only "RW/MRW" differences found:

HVM-boot-params (MRW): order: dc; firmware: bios
HVM-boot-params (MRW): order: dc

platform (MRW): ...; secureboot: false
platform (MRW): ...

I've removed those two param keys from the failing VM but it did not change the behaviour.

@blueh2o
Ooops, sorry - I read your message the wrong way around. You're right, that sounds really weird in your case....

I'm currently trying to migrate our XenServer 7.1.2 pool to XCP-ng 8.3. We have 3 hosts and central LVMoiSCSI storage for the SRs.

After upgrading the pool master to XCP 8.3 including all patches, I've been able to migrate some VMs to that host. Live migration didn't work, but a shutdown and restart on the upgraded master did the trick.

It seems that the luck didn't endure for long, as currently, moving VMs is struggling on next 3 VMs in the queue with the error:

XOA:
++++++++++
INTERNAL_ERROR(Not_found)
++++++++++

or by command line:
++++++++++
The server failed to handle your request, due to an internal error. The given message may give details useful for debugging the problem.
message: Not_found
++++++++++

daemon.log & xensource.log and details in XOA log don't give me much more details, either, but maybe someone can spot a hint.
There are no .iso attached, no snapshots on the VMs in question.

BfN, -k

xoa.txt
daemon.txt
xensource.txt

Hi,

Similar to VMware, XCP-ng is also coming with its own 'guest tools', which enables the full feature-set on VMs. This message is only about those XCP guest tools, so after you install them, the message will disapear.

BfN, -k