Well, it seems like it works if I create a snapshot and create a new VM from the snapshot on the new server.

Should be workable for my need.

I have an old XenServer 6.5 pool with a few VMs. I am trying to move them to a new server running XCP-ng 8.2.1 - same error when trying to move to another older but 7.5 server. I know 6.5 is ancient - that's why I am moving the VMs.

All I get is operation failed.

In detailed view of the error it shows "code 21". Internal error.

xo-server 5.91.0

I can do this by exporting to xva file, then importing, but that's painfully slow.

Any recommendation?

For what it's worth, I was having Windows 2016 freezes regularly (every few days or week). I could never trace it back to a specific cause, though I noticed very high number of handles and threads when it was hanging.

Per my records, it stopped hanging after I upgraded the PV drivers using Guest Tool ISO 7.41.0-1.

CPU are Intel E5-2609 v4 @ 1.70GHz in this case.

Overall stats show CPU below 50% usage overall, load average between 3-4 during continue replication job.

Dom0 top show 2-3 load average.

Wow, switching to http made quite a difference! By rough calculation, time to do a continuous replication is about 1/4 of what it previously was.

My XOA is connected to a 1Gbps interface and so are the various XCP servers. This is a dedicated network for VM server management / VM replication.

As comparison, a 1.76TiB VM took 11 hours 28 min to do it's initial replication when running on https. But once https was turned off, a different VM which is 4.28TiB, took 19 hours and 58 minutes. It was the first time I was able to do an initial replication on this VM as previously, it would take more than 24 hours and XCP would kill the job.

Smaller continuous replication jobs (deltas) are also faster. 40-60 minutes to do a 120GiB delta with https, on http took 25 minutes.

I can probably gain more by moving the replication to a 10G network - or at least XOA will be able to deal better with concurrent replication jobs between different servers since it all funnels through XOA.

Were you able to resolve this in the end?