Ubuntu
qemu package

  1. Bug #1783140
  2. Comment #30

Comment 30 for bug 1783140

Revision history for this message
bugproxy (bugproxy) wrote : Comment bridged from LTC Bugzilla

------- Comment From <email address hidden> 2018-09-07 08:38 EDT-------
I have some more bad surprises:
On Monday I upgraded my x86 KVM hypervisors from 16.04.5 to 18.04.1.
No problems at all.

On Wednesday I upgraded the ppc KVM hypervisors from 16.04.5 to 18.04.1.

Problem 1:
In the middle of the upgrade process I could not live migrate the guests from the 16.04 hypervisor to the 18.04 hypervisor.
None of the 13 guests!

root@pkvm2:~# virsh migrate --persistent --live pkut04 qemu+ssh://pkvm1/system
error: internal error: process exited while connecting to monitor: 2018-09-05T11:07:58.260851Z qemu-system-ppc64: warning: CPU(s) not present in any NUMA nodes: CPU 1 [core-id: 1]
2018-09-05T11:07:58.260859Z qemu-system-ppc64: warning: All CPU(s) up to maxcpus should be described in NUMA config, ability to start up with partial NUMA mappings is obsoleted and will be removed in future
2018-09-05T11:07:58.262038Z qemu-system-ppc64: This machine version does not support CPU hotplug

So I had to shutdown all the guests to do the upgrade of the second hypervisor !!!

Probem 2:
When the second hypervisor was on 18.04.1 I could not start most of the guests.
Only 4 of 13 guests started.
(a) some qcow2 disks have been marked as sharable
worked on Ubuntu 16.04, but noot on 18.04
(b) vcpu definition
on Ubuntu 16.04 <vcpu placement='static' current='8'>160</vcpu> worked
on Ubuntu 18.04 this does not work on ppc ("This machine version does not support CPU hotplug").
I had to cahnge it to <vcpu placement='static'>8</vcpu>

I could resolve 2a and 2b. But it is frustrating to get such additional adventure games in the maintenance window.
You think "just start the guests, then I can go home", and then the guests do not start.
And it is even more frustrating when you did just the same task 2 days ago on x86 without any problems.

Maybe Problem 1 has the same reason as Problem 2. In other words: With the changed domain XML, maybe a live migration from Ubuntu 16.04 hypervisor to 18.04 hypervisor would work.
But I cannot verify this assumption. Now both my hypervisors are finally on 18.04.1 and live migration between them works for all guests.